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HomeMy WebLinkAbout010_BIKEFILL ONSITE DRAINAGE REPORT DRAINAGE REPORT 22147.01 Bozeman, MT AUGUST 2026 FOR BIKEFILL BIKE PARK DRAINAGE REPORT FOR BIKEFILL BIKE PARK CERTIFICATION I hereby state that this Final Drainage Report has been prepared by me or under my supervision and meets the standard of care and expertise which is usual and customary in this community of professional engineers. The analysis has been prepared utilizing procedures and practices specified by the City of Bozeman and within the standard accepted practices. Robert Egeberg, P.E. Date 8/18/2026 August 18, 2026 Project No. 22147.01 STORM DRAINAGE REPORT FOR BIKEFILL BIKE PARK BOZEMAN, MONTANA INTRODUCTION The project is in the City of Bozeman within Gallatin County, Montana. The purpose of this storm drainage report is to describe the drainage design associated with the improvements to the Bikefill Bike Park located east of McIlhattan Road. The proposed park and parking lot will be situated to the east of the separately improved section of McIlhattan Road, north of St. Andrews Drive and south of Snowfill Dog Park. HYDROLOGY The detention volumes for each basin are designed using the full range of storm events, which includes the 2-year through 100-year storms per the City of Bozeman Design and Construction Standards (COBDCS), October 2024. Calculations for 2-year, 5-year, 10-year, 25-year, 50-year, and 100-year storm events are provided in this report. Subbasin watersheds were delineated based on the existing and proposed site topography, as shown in Appendix A. The rational method was used, in accordance with the City of Bozeman Design and Construction Standards. Hydraflow was used for hydrology and pond routing calculations. The City of Bozeman Frequency Correction Factors for the Rational Method were applied to the City’s Precipitation-Depth-Duration table, as the software does not allow for varying runoff coefficients for each storm interval. Thus, in highly impervious areas, the curve number may be artificially inflated above 1.0 and may lead to an overestimation of peak flow and a more conservative basin design, as all pre-development flow rates were calculated from pervious basins. The unadjusted weighted runoff coefficients are reported for ponds using the adjusted Precipitation-Depth-Duration table. Pond 1 and 2 are full retention ponds, and their retention volumes were calculated directly from their basin characteristics, thus, the runoff coefficients are reported as weighted coefficients adjusted with the City of Bozeman Frequency Correction Factors. Hydrology calculations are provided in Appendix B. 2 (08/17/26) ALS/RPE All existing subbasins were delineated using the site topography. Within these watersheds, impervious, pervious, and gravel areas were determined to calculate the weighted runoff coefficients for each watershed. Runoff Coefficients Impervious 0.95 Pervious 0.20 Gravel 0.75 EXISTING STORMWATER DRAINAGE CONDITIONS Existing drainage conditions for the proposed project site include public open land with native plants and grasses that slope downwards from east to west across the site, towards McIlhattan Road. There is a ridge running east/west across the property that forces drainage to flow either to existing drainages on the north and south sides of the property. The stormwater drainages for the areas being impacted by impervious areas such as the asphalt parking lot, Family Hub, and asphalt pump tracks have been delineated and accounted for as part of the stormwater design. The other trails and upper trails have not been delineated at this time since it is assumed they will be natural features and historic drainage patterns will be maintained. Stormwater drainage is split into ten different subbasins. These delineated subbasins can be seen in Exhibit A of Appendix A. Pre-development hydrographs and associated hydrology were created using Hydraflow software, and the calculated pre-development flow rates were used as design discharge constraints for post-development discharge. In cases where post-development conditions collect multiple basins, the basins were combined into one hydrograph to compare pre- and post-development flow rates. The pre-development hydrology calculations can be seen below and in Appendix B. There is one existing culvert, 30-inches CMP, which collects drainage from Churn Creek and crosses McIlhattan Road that will be replaced. This culvert will be replaced as part of a separate project for McIlhattan Road and the hydraulics associated with this replacement have been included in the McIlhattan Road drainage report, Appendix H. PROPOSED STORMWATER DRAINAGE SYSTEM The proposed drainage system associated with the new Bikefill Bike Park improvements will consist of new asphalt, curb and gutter, inlets/outfalls, culverts, and underground storage with either gravel or chambers. The proposed drainage has been split into ten on-site drainage basins and two off-site drainage basins. Refer to Appendix A, to see the watersheds. The captured flow will be conveyed to the existing wetland basins or Churn Creek to perpetuate historical drainage. In captured areas, the water quality and quantity volume will be stored and released at pre-development flowrates. 3 (08/17/26) ALS/RPE It is anticipated that drywells/boulder pits will be installed as part of the pump track installation. However, we have designed the detention and retention ponds within the parking lot to accept all the upstream drainage in the Family Hub area, including the pump tracks in the event no upstream storage is provided. If any additional storage is provided upstream, it will only improve the performance of the downstream drainage system within the parking lot but is not required. Required Storage Volume Calculations – 100-Year Storm There are six proposed storage areas proposed within the design of the project. The storage has been designed to capture the runoff volume from the full range of storm events for multiple proposed watershed basins. Each storage area has been designed as a retention facility or a detention facility. Detention facilities release runoff events at the pre-development flowrate for the minor and major storm event, and discharge does not exceed the pre-development flow rate for each calculated storm event (2-year, 5-year, 10-year, 25-year, 50-year, and 100-year). The pre-development peak flowrates for the combined basins contributing to each proposed pond are shown below for comparison to post-development discharge. 2-yr Qpeak (cfs) 5-yr Qpeak (cfs) 10-yr Qpeak (cfs) 25-yr Qpeak (cfs) 50-yr Qpeak (cfs) 100-yr Qpeak (cfs) Basin 1 – Pond 1 0.03 0.04 0.05 0.06 0.07 0.07 Basin 2 – Pond 2 0.02 0.03 0.04 0.04 0.05 0.06 Basin 3 – Pond 3 0.28 0.42 0.52 0.64 0.73 0.82 Basin 4,5,8 – Pond 4 0.41 0.62 0.76 0.93 1.06 1.19 Basin 6,9 - Pond 5 0.08 0.12 0.15 0.19 0.21 0.24 Pond 7,10 – Pond 6 Runoff 0.10 0.15 0.18 0.22 0.26 0.29 Combined Routed Pond 6 0.40 0.60 0.73 0.90 1.02 1.15 Full calculations for pre- and post-development peak flowrates, required storage volumes, and basin characteristics are provided in Appendix B. Pond 1 Proposed basin one is fully retained for the post-development runoff from the major storm (100-year, 24-hour) by Pond 1. Percolation was not used when sizing the pond. The basin has an area of 0.13-acres and has a runoff coefficient of 0.74. Full retention of post-development runoff from the major storm (100-year, 24-hour) is required where no viable receiving conveyance channel or drainage system is available. The major storm 100-year, 24-hour required retention volume is 1,001-ft3. The surface pond has a volume of 764-ft3, while the gravel storage underground has a volume of 840-ft3, making the total storage of the retention system 1,604-ft3. Thus, the storm system is 4 (08/17/26) ALS/RPE adequate to meet the storage requirements. A portion of the gravel in the retention system was not required for storage but was added to tie into native gravels and infiltrate the runoff within 72 hours. Runoff enters the gravel via a beehive inlet with a 9-inch sump and then flows through a perforated pipe to help distribute the water evenly within the gravel section. V = (C x I x A x t x 60) Where: C=0.92; i=0.10; A=0.13 acres; t=1440 min Water Quantity Volume=1,001-ft3 Pond 1 Required Volume=1,001-ft3 Pond 1 Draw-Down Time Using test pits in each proposed pond depth to suspected native gravel deposits were determined. Test pits can be found in Appendix G. In all test pits ground water was not encountered. From the geotechnical report this soil has a USCS classification of GC. USCS allows a maximum infiltration rate of 0.50 inches/hour. On July 6th, 2026 Sanbell conducted infiltration testing in accordance with DEQ-8. During infiltration testing this soil was observed to have an infiltration rate of nearly 1 inch/hour, thus making the 0.50 inches/hour from USCS a viable rate to use for calculations. Drawdown time = 1,001 ft3 / 400 ft2 / 0.042 ft/hr = 60 hours. Pond 2 Proposed basin two is fully retained for the post-development runoff from the major storm (100-year, 24-hour) by Pond 2. Percolation was not used when sizing the pond. The basin has an area of 0.08-acres and has a runoff coefficient of 0.63. Full retention of post-development runoff from the major storm (100-year, 24-hour) is required where no viable receiving conveyance channel or drainage system is available. The major storm 100-year, 24-hour required retention volume is 510-ft3. The surface pond has a volume of 691-ft3, while the gravel storage underground has a volume of 360- ft3, making the total storage of the retention system 1,051-ft3. Thus, the storm system is adequate to meet the storage requirements. Gravel in the pond was not added for storage but was added to tie into native gravels and infiltrate the runoff within 72 hours of cessation of the storm event. Runoff enters the gravel via a beehive inlet with a 9-inch sump and then flows through a perforated pipe to help distribute the water evenly within the gravel section. V = (C x I x A x t x 60) Where: C=0.79; i=0.10; A=0.08 acres; t=1440 min 5 (08/17/26) ALS/RPE Water Quantity Volume=510-ft3 Pond 2 Required Volume=510-ft3 Pond 2 Draw-Down Time Drawdown time = 510 ft3 / 200 ft2 / 0.042 ft/hr = 61 hours. Pond 3 Proposed basin three is detained by the proposed surface Pond 3 and ADS A chamber system for the 100-year storm event. The basin has a total area of 1.68-acres and a runoff coefficient of 0.63, a required water quantity storage of 3,369-ft3, and a water quality storage of 731-ft3. The surface pond has a volume of 1,319-ft3 and the ADS chamber system underground has a volume of 2,324-ft3, for an overall total volume of 3,643-ft3, making the storm system adequate to meet the storage requirements. The 100-year pre-development peak flow 0.82-cfs was used as a discharge rate when sizing the pond and chamber system, and the discharge during each flood event is limited to the pre-development flow rate. The pond discharges through a curb cut that functions as a weir and flows north towards Pond 6. The curb cut has been sized to discharge during the 25-year, 50-year, and 100-year flow only, since the 2-year through the 10-year storm are retained prior to reaching the curb cut weir. Until volume within the pond reaches 3,250-ft3 the pond acts as a retention pond. Once runoff volume reaches the weir the pond becomes a detention system. WQV = (((P)(Rv)(A))/12) x 43,560 Where: P=0.5, Rv=0.38; A=0.88-acres Water Quality Volume=731-ft3 Pond 3 Required Volume=3,369-ft3 Pond 3 Draw-Down Time Drawdown time = 3,369 ft3 / 1,136 ft2 / 0.042 ft/hr = 71 hours. Pond 4 Proposed basin 4, 5, and 8 are detained by the proposed surface Pond 4 and ADS B chamber system for the full range of storm events. The basin has a total area of 1.23- acres and have a runoff coefficient of 0.71, a required water quantity storage of 2,404- ft3, and a water quality storage of 1,287-ft3. The surface pond has a volume of 364-ft3 and the ADS chamber system has a volume of 2,065-ft3, for an overall total volume of 2,429-ft3, making the storm system adequate to meet the storage requirements. The pre-development peak flows were used as a discharge rate when sizing the pond and 6 (08/17/26) ALS/RPE chamber system. Additional storage in the chamber system is from tying bottom stone into native gravels to infiltrate runoff within 72 hours of cessation of the storm event. In the event of a storm, the ADS chamber system will act as a retention pond until runoff volume exceeds 2,074-cfs. The system will then work as a detention pond with runoff filling the surface pond and flowing out the outfall structure towards the wetland area. Water flowing from northeast of the pump track above proposed basins 3 and 4 will be routed through the historical crossing northeast of the pump track to Snowfill Recreation Area through a trapezoidal drainage swale. The swale has been sized to convey a 100-year flood of 94.7 cfs (determined from USGS StreamStats) with a 5-foot channel width and 3:1 side slopes. See Appendix C and sheet C5.2 for hydraulic calculations and location of the drainage swale. With the drainage swale conveying flow from the northeast away from the pump track through the historical drainage patterns, the pump track and surface pond will not need to accommodate drainage from northeast of the site. WQV = (((P)(Rv)(A))/12) x 43,560 Where: P=0.5, Rv=0.57; A=1.23-acres Water Quality Volume=1,287-ft3 Pond 4 Required Volume=2,404-ft3 Pond 4 Draw-Down Time Drawdown time = 2,404 ft3 / 854 ft2 / 0.042 ft/hr = 67 hours. Pond 5 Proposed basins 6 and 9 are detained by the proposed surface Pond 5 for the full range of storm events. The basin has an area of 0.38-acres and has a runoff coefficient of 0.74, a required water quantity storage of 955-ft3, and a water quality storage of 486-ft3. The surface pond has a volume of 283-ft3, while the gravel storage underground stores 675-ft3, making the total storage of the detention system 958-ft3. This is adequate to meet the storage requirements. Pre-development peak flow rates were used as a discharge rate when sizing the detention pond. Pond 5 discharges to pond 6 via an outlet structure. The structure has been sized to release the pre-development discharge rates for basins 6 and 9 to pond 6. WQV = (((P)(Rv)(A))/12) x 43,560 Where: P=0.5, Rv=0.69; A=0.38-acres Water Quality Volume=486-ft3 7 (08/17/26) ALS/RPE Pond 5 Required Volume=955-ft3 Pond 5 Draw-Down Time Drawdown time = 955 ft3 / 900 ft2 / 0.042 ft/hr = 25 hours. Pond 6 Proposed basins 3, 6, 7, 9, and 10 are detained by the proposed surface ponds 3, 5, and ultimately 6. The proposed surface pond 6 has been sized to release the combined pre- development discharge rates for basins 3, 6, 7, 9 and 10. Pond 6 inflow was calculated as the combined inflow from the routed Pond 3 outflow, the routed Pond 5 outflow, and runoff from proposed basins 7 and 10. The combined runoff basin (7 and 10) has an area of 0.49-acres and has a runoff coefficient of 0.84, and a water quality storage of 727-ft3. Because the water quality storage for Ponds 3 and 5 was met in each respective pond, the total required water quality storage for Pond 6 is 727-ft3. The required water quantity storage for the combined routed inflow to Pond 6 from the two ponds and runoff is 1,188-ft3. Pond 6 has a surface pond volume of 987-ft3, while the gravel storage has a volume of 787-ft3, making the total storage of the detention system 1,774-ft3. Pre- development peak flows were used as a discharge rate when sizing the detention pond. Gravel in the pond was not added for storage but was added to tie into native gravels and infiltrate the runoff within 72 hours of cessation of the storm event and to treat the 727-cf of water quality volume within basins 7 and 10. Runoff enters the gravel underground via a beehive inlet with a 9-inch sump and then flows through a perforated pipe to help distribute the water evenly within the gravel section. WQV = (((P)(Rv)(A))/12) x 43,560 Where: P=0.5, Rv=0.82; A=.49-acres Water Quality Volume=727-ft3 Pond 6 Required Volume=1,118-ft3 Pond 6 Draw-Down Time Drawdown time = 1,188 ft3 / 750 ft2 / 0.042 ft/hr = 38 hours. Offsite-1 Basin Offsite-1 will be detained by ADS Chamber System C within the McIlhattan Road project. At the time the McIlhattan Road project storm report was submitted it was anticipated that the grading of the Bikefill approach would flow onsite. However, to make onsite grading effective, half of the approach flows towards the road project. Offsite-1 has an area of 0.13 acres and has a runoff coefficient of 0.41 and a required 8 (08/17/26) ALS/RPE water quality storage of 73-ft3. ADS Chamber System C had been sized for water quality and the minor storm event and has a storage volume of 755-ft3 and currently has a planned storage of 602-ft3, therefore adding an additional 73-ft3 of water quantity storage still allows for an appropriate design of the storage system. See Appendix F for the McIlhattan Road Drainage Report. There is no structure designed to reduce flow from the approach to the ADS Chamber System C within the ditch. The discharge rate is from the structure within ADS Chamber System C. V = (C x i x A x t x 60)-(d x t x 60) Where: C=0.41; i=3.87; A=0.13 acres; t=5 min; d=0.58-cfs Water Quantity Volume=0-ft3 WQV = (((P)(Rv)(A))/12) x 43,560 Where: P=0.5, Rv=0.30; A=0.13-acres Water Quality Volume=73-ft3 ADS Chamber C Required Quality Volume=675-ft3; Available=755-ft3 Offsite-2 Basin Offsite-2 is not captured by proposed storm infrastructure. This basin continues its existing drainage pattern and flows towards existing drainage facilities north of the approach and east of McIlhattan Road. The amount of impervious area has not increased significantly enough in this area to affect existing storm infrastructure as peak flow increases by approximately 0.06 cfs in this area. Water Quality The City of Bozeman has a requirement to capture or reuse the runoff generated from the first 0.5-inches of rainfall from a 24-hour storm. This requirement is met by detaining or retaining runoff on-site in the six ponds. Stormwater detention and retention systems need to be maintained, per the recommendations in the Operations and Maintenance Manual, see Appendix D. Storm Piping Design Storm drain pipes exiting outfall structures, were sized to handle peak flow resulting from the major storm. All storm drain pipes were designed with a minimum slope to maintain a full-flow velocity of at least 2.5-feet per second while limiting the full flow velocity to a maximum of 12-feet per second. The Federal Highway Administration (FHWA) Hydraulic Toolbox Software Version 5.3.0 was used to determine pipe sizing for the full flow capacity of the pipes. 9 (08/17/26) ALS/RPE One 15” RCP culvert is proposed along the McIlhattan Road trail at Station 5+35.2. This culvert will convey drainage collected from the north that flows down from the fill that begins at the City of Bozeman owned parking lot at 2143 Story Mill Road to a culvert proposed for the McIlhattan Road project. The flow area and design flows are described in Appendix H for the culvert in the McIlhattan Road project under Basin 3, and the proposed culvert under the trail is designed to convey flow to that culvert with the same design parameters. The culvert was also modeled in Hydraflow. For further information on storm drain and culvert capacity calculations, see Appendix B and Appendix C. OUTLET STRUCTURES Ponds 1 and 2 have been designed as full retention ponds for the post-development major storm and do not have an outlet structure. Pond 3 has been designed to have an overflow curb opening that releases the full range of storm events to the pre-development peak flow rates. The pond will retain water for the 2-year through the 10-year event as the hydraulic volume generated from the storms do not exceed the volume required to reach the weir. Ponds 4, 5, and 6 have been designed using orifices within a structure similar to the COB Standard Drawing No. 02720-12. Orifices had been calculated to release runoff at pre-development runoff rates for the range of storm events. Each orifice was designed and modeled in Hydraflow, and the full results from the model can be viewed in Appendix B. The following summarizes the outlet and pond design for each pond: Pond 3 Includes runoff from Basin 3 Bottom of Chamber System Elevation = 4695.50’ Stone Encasement = 3.75’ deep, 30% porosity Top of Chamber System Elevation = 4698.75’ Top of Surface Pond Elevation = 4703.28’ Provide 0.60’ curb cut weir as called out in drawings. 2-yr, Q-discharge = 0-cfs Max Elevation= 4697.03’ Max Storage= 1,460 cf 5-yr, Q-discharge = 0-cfs Max Elevation= 4698.40’ Max Storage= 2,204 cf 10-yr, Q-discharge = 0-cfs Max Elevation= 4702.25’ Max Storage= 2,696 cf 25-yr, Q-discharge = 0.16-cfs Max Elevation= 4702.92’ Max Storage= 3,250 cf 50-yr, Q-discharge = 0.49-cfs Max Elevation= 4703.12’ Max Storage= 3,472 cf 100-yr, Q-discharge = 0.81-cfs Max Elevation= 4703.28’ Max Storage= 3,639 cf 10 (08/17/26) ALS/RPE Pond 4 Includes runoff from Basins 4, 5 and 8 Bottom of Chamber System Elevation = 4692.25’ Stone Encasement = 5.50’ deep, 30% porosity Top of Chamber System Elevation = 4695.50’ Top of Surface Pond Elevation = 4702.00 Provide 12-inch riser pipe in discharge outlet structure with the following: One 5.0” hole with invert at 4699.70’ One 2.0” hole with invert at 4701.00’ One 0.5” hole with invert at 4701.50’ 2-yr, Q-discharge = 0-cfs Max Elevation= 4693.26’ Max Storage= 1,163 cf 5-yr, Q-discharge = 0-cfs Max Elevation= 4694.38’ Max Storage= 1,751 cf 10-yr, Q-discharge = 0.26-cfs Max Elevation= 4700.06’ Max Storage= 2,078 cf 25-yr, Q-discharge = 0.70-cfs Max Elevation= 4701.03’ Max Storage= 2,169 cf 50-yr, Q-discharge = 0.90-cfs Max Elevation= 4701.51’ Max Storage= 2,270 cf 100-yr, Q-discharge = 1.03-cfs Max Elevation= 4701.92’ Max Storage= 2,404 cf Pond 5 Includes runoff from Basins 6 and 9 Bottom of Underground Gravel Elevation = 4698.20’ Top of Underground Gravel Elevation = 4700.70’ Top of Surface Pond Elevation = 4702.50 Provide 8-inch riser pipe in discharge outlet structure with the following: One 2.0” hole with invert at 4700.49’ One 1.5” hole with invert at 4700.80’ One 1.0” hole with invert at 4702.30’ 2-yr, Q-discharge = 0-cfs Max Elevation= 4699.65’ Max Storage= 391 cf 5-yr, Q-discharge = 0-cfs Max Elevation= 4700.38’ Max Storage= 590 cf 10-yr, Q-discharge = 0.13-cfs Max Elevation= 4701.26’ Max Storage= 693 cf 25-yr, Q-discharge = 0.19-cfs Max Elevation= 4701.95’ Max Storage= 791 cf 50-yr, Q-discharge = 0.21-cfs Max Elevation= 4702.26’ Max Storage= 871 cf 100-yr, Q-discharge = 0.23-cfs Max Elevation= 4702.49’ Max Storage= 955 cf Pond 6 Includes surface runoff from Basins 7 & 10, and routed discharge from Ponds 3 & 5. Bottom of Underground Gravel Elevation = 4689.91’ Top of Underground Gravel Elevation = 4693.41’ Top of Surface Pond Elevation = 4699.61’ Provide 12-inch riser pipe in discharge outlet structure with the following: One 4.0” hole with invert at 4695.61’ One 2.0” hole with invert at 4696.79’ One 1.0” hole with invert at 4698.14’ 11 (08/17/26) ALS/RPE 2-yr, Q-discharge = 0-cfs Max Elevation= 4692.46’, Max Storage= 574 cf 5-yr, Q-discharge = 0.34-cfs Max Elevation= 4696.42’ Max Storage= 801 cf 10-yr, Q-discharge = 0.50-cfs Max Elevation= 4696.99’ Max Storage= 840 cf 25-yr, Q-discharge = 0.64-cfs Max Elevation= 4697.54’ Max Storage= 914 cf 50-yr, Q-discharge = 0.72 -cfs Max Elevation= 4697.92’ Max Storage= 990 cf 100-yr, Q-discharge = 0.85 -cfs Max Elevation= 4698.55’ Max Storage= 1,188 cf The table below shows the combined pre-development discharge rates compared to the post-development discharge rates split by the post-development outfall locations for the site. The combined northern basins 1, 4, 5 and 8 are shown in comparison to the combined post-development discharge from Pond 4, and the combined southern basins 2, 3, 6, 7, 9 and 10 in comparison to the combined post-development discharge from Pond 6. Combined North Runoff – Pond 4 Combined South Runoff – Pond 6 Storm Interval Pre- Development Qpeak (cfs) Post- Development Qpeak (cfs) Pre- Development Qpeak (cfs) Post- Development Qpeak (cfs) 2-year 0.43 0.00 0.40 0.00 5-year 0.65 0.00 0.60 0.34 10-year 0.79 0.26 0.74 0.50 25-year 0.98 0.70 0.91 0.64 50-year 1.11 0.90 1.04 0.72 100-year 1.25 1.03 1.16 0.85 GROUNDWATER MOUNDING CALCULATIONS Groundwater mounding calculations were completed as recommended by the City of Bozeman Design and Construction Standards using the Hantush method provided by the USGS. Each storm pond has gravel proposed to tie the bottom of the storm pond in with existing the existing native gravel found in test pits onsite to promote infiltration to groundwater. The existing native layer is clayey gravel with sand. A maximum infiltration rate of 0.5-inches per hour (1-foot per day) was used for each pond per USCS determination of soils on the site. A conservative horizontal hydraulic conductivity of ten times the infiltration rate was used as assumed by the USGS SIR 2010-5102 report accompanying the Hantush method spreadsheet used. This rate correlates well with reported values for clayey gravels with sand. A specific yield of 0.015 was used for each pond correlating with gravels with some fines as per the test pit sieve results. The half width and length of each storm pond were input as the half length extents of the gravel tying the storm pond to native gravels, and the infiltration period duration was set as 72-hours (3-days). The initial thickness of the saturated zone is unknown. The deepest nearby well found on GWIC (GWIC ID 147681) shows a total depth of 240-feet with a static water level of 105-feet, indicating a saturated zone thickness of at least 135-feet. No deeper wells were found, and an initial saturated zone thickness of 135-feet was 12 (08/17/26) ALS/RPE assumed in groundwater mounding calculations. Results of mounding were changed by a few tenths of a foot when the saturated zone thickness was increased to 200- and 500-feet, but with no foundations nearby the ponds, mounding is best represented under the ponds by a lower, more conservative estimate. Groundwater mounding calculations under each proposed storm pond and up to 120-feet away are shown in Appendix G. Maximum mounding under the center of each storm pond is 0.157-feet at Pond 1, 0.091-feet at Pond 2, 0.276-feet at Pond 3, 0.313-feet at Pond 4, 0.309-feet at Pond 5, and 0.215-feet and Pond 6. All pond bottoms are well above the mounding height. CONCLUSION All runoff from the new hardscape and landscape areas being constructed will be captured and detained or retained on-site matching historical flow patterns. There are two retention ponds and four detention ponds that will be constructed. Surface ponds 3 and 4 also have additional storage below grade within ADS chambers, while ponds 1, 2, 5, and 6 have additional gravel storage below grade. The proposed detention ponds capture and release outflow at the pre-development peak flow rates for the full range of storm events. The proposed retention ponds fully retain the post-development 100- year, 24-hour storm. APPENDICES Appendix A – Stormwater Basins Appendix B – Hydrology Calculations Appendix C – Hydraulic Calculations Appendix D – Groundwater Mounding Calculations Appendix E – O&M Plan Appendix F – TD&H Geotechnical Report Appendix G – Additional Test Pit Data Appendix H – McIlhattan Road Drainage Report APPENDIX A STORMWATER BASINSBIKEFILL BIKE PARK 22147.01 030SCALE:1" = 60'6030 030SCALE:1" = 60'6030 APPENDIX B HYDROLOGY CALCULATIONS BIKEFILL BIKE PARK 22147.01 Hydraflow Table of Contents 22147_Bikefill_Onsite_Hydraflow.gpw Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hydrograph Return Period Recap............................................................................. 1 2 - Year Summary Report......................................................................................................................... 2 Hydrograph Reports................................................................................................................... 3 Hydrograph No. 1, Mod. Rational, Pre-Development Basin 3-Pond 3..................................... 3 TR-55 Tc Worksheet............................................................................................................ 4 Hydrograph No. 2, Mod. Rational, Post-Development Basin 3-Pond 3.................................... 5 TR-55 Tc Worksheet............................................................................................................ 6 Hydrograph No. 3, Mod. Rational, Total Pre-Development Basins 4,5&8-Pond 4................... 7 TR-55 Tc Worksheet............................................................................................................ 8 Hydrograph No. 4, Mod. Rational, Tota Post-Development Basins 4,5&8-Pond 4................... 9 TR-55 Tc Worksheet.......................................................................................................... 10 Hydrograph No. 5, Mod. Rational, Total Pre-Development Basins 6&9-Pond 5.................... 11 TR-55 Tc Worksheet.......................................................................................................... 12 Hydrograph No. 6, Mod. Rational, Total Post-Development Basins 6&9-Pond 5................... 13 Hydrograph No. 7, Mod. Rational, Total Pre-Development Basins 7&10-Pond 6.................. 14 TR-55 Tc Worksheet.......................................................................................................... 15 Hydrograph No. 8, Mod. Rational, Total Post-Development Basins 7&10-Pond 6................. 16 Hydrograph No. 9, Reservoir, Pond 3 Routed Outflow........................................................... 17 Pond Report - POND 3...................................................................................................... 18 Hydrograph No. 10, Reservoir, Pond 5 Routed Outflow......................................................... 19 Pond Report - POND 5...................................................................................................... 20 Hydrograph No. 11, Combine, Total Pond 6 Routed Inflow (P3,P5,B7&B10)........................ 21 Hydrograph No. 12, Combine, Total Pond 6 Pre-Development Inflow (B3,6,7,9,10)............. 22 Hydrograph No. 13, Reservoir, Pond 6 Routed Outflow......................................................... 23 Pond Report - POND 6...................................................................................................... 24 Hydrograph No. 14, Mod. Rational, Pre-Development Basin 1-Pond 1................................. 25 TR-55 Tc Worksheet.......................................................................................................... 26 Hydrograph No. 15, Mod. Rational, Pre-Development Basin 2-Pond 2................................. 27 TR-55 Tc Worksheet.......................................................................................................... 28 Hydrograph No. 16, Reservoir, Pond 4 Routed Outflow......................................................... 29 Pond Report - POND 4...................................................................................................... 30 Hydrograph No. 17, Mod. Rational, McIlhatten Basin 3 - Offsite............................................ 31 Hydrograph No. 18, Mod. Rational, 8-inch Culvert Drainage................................................. 32 Hydrograph No. 19, Combine, Total Pre-Development North................................................ 33 Hydrograph No. 20, Combine, Total Pre-Development South................................................ 34 5 - Year Summary Report....................................................................................................................... 35 Hydrograph Reports................................................................................................................. 36 Hydrograph No. 1, Mod. Rational, Pre-Development Basin 3-Pond 3................................... 36 Hydrograph No. 2, Mod. Rational, Post-Development Basin 3-Pond 3.................................. 37 Hydrograph No. 3, Mod. Rational, Total Pre-Development Basins 4,5&8-Pond 4................. 38 Hydrograph No. 4, Mod. Rational, Tota Post-Development Basins 4,5&8-Pond 4................. 39 Hydrograph No. 5, Mod. Rational, Total Pre-Development Basins 6&9-Pond 5.................... 40 Hydrograph No. 6, Mod. Rational, Total Post-Development Basins 6&9-Pond 5................... 41 Hydrograph No. 7, Mod. Rational, Total Pre-Development Basins 7&10-Pond 6.................. 42 Contents continued...22147_Bikefill_Onsite_Hydraflow.gpw Hydrograph No. 8, Mod. Rational, Total Post-Development Basins 7&10-Pond 6................. 43 Hydrograph No. 9, Reservoir, Pond 3 Routed Outflow........................................................... 44 Hydrograph No. 10, Reservoir, Pond 5 Routed Outflow......................................................... 45 Hydrograph No. 11, Combine, Total Pond 6 Routed Inflow (P3,P5,B7&B10)........................ 46 Hydrograph No. 12, Combine, Total Pond 6 Pre-Development Inflow (B3,6,7,9,10)............. 47 Hydrograph No. 13, Reservoir, Pond 6 Routed Outflow......................................................... 48 Hydrograph No. 14, Mod. Rational, Pre-Development Basin 1-Pond 1................................. 49 Hydrograph No. 15, Mod. Rational, Pre-Development Basin 2-Pond 2................................. 50 Hydrograph No. 16, Reservoir, Pond 4 Routed Outflow......................................................... 51 Hydrograph No. 17, Mod. Rational, McIlhatten Basin 3 - Offsite............................................ 52 Hydrograph No. 18, Mod. Rational, 8-inch Culvert Drainage................................................. 53 Hydrograph No. 19, Combine, Total Pre-Development North................................................ 54 Hydrograph No. 20, Combine, Total Pre-Development South................................................ 55 10 - Year Summary Report....................................................................................................................... 56 Hydrograph Reports................................................................................................................. 57 Hydrograph No. 1, Mod. Rational, Pre-Development Basin 3-Pond 3................................... 57 Hydrograph No. 2, Mod. Rational, Post-Development Basin 3-Pond 3.................................. 58 Hydrograph No. 3, Mod. Rational, Total Pre-Development Basins 4,5&8-Pond 4................. 59 Hydrograph No. 4, Mod. Rational, Tota Post-Development Basins 4,5&8-Pond 4................. 60 Hydrograph No. 5, Mod. Rational, Total Pre-Development Basins 6&9-Pond 5.................... 61 Hydrograph No. 6, Mod. Rational, Total Post-Development Basins 6&9-Pond 5................... 62 Hydrograph No. 7, Mod. Rational, Total Pre-Development Basins 7&10-Pond 6.................. 63 Hydrograph No. 8, Mod. Rational, Total Post-Development Basins 7&10-Pond 6................. 64 Hydrograph No. 9, Reservoir, Pond 3 Routed Outflow........................................................... 65 Hydrograph No. 10, Reservoir, Pond 5 Routed Outflow......................................................... 66 Hydrograph No. 11, Combine, Total Pond 6 Routed Inflow (P3,P5,B7&B10)........................ 67 Hydrograph No. 12, Combine, Total Pond 6 Pre-Development Inflow (B3,6,7,9,10)............. 68 Hydrograph No. 13, Reservoir, Pond 6 Routed Outflow......................................................... 69 Hydrograph No. 14, Mod. Rational, Pre-Development Basin 1-Pond 1................................. 70 Hydrograph No. 15, Mod. Rational, Pre-Development Basin 2-Pond 2................................. 71 Hydrograph No. 16, Reservoir, Pond 4 Routed Outflow......................................................... 72 Hydrograph No. 17, Mod. Rational, McIlhatten Basin 3 - Offsite............................................ 73 Hydrograph No. 18, Mod. Rational, 8-inch Culvert Drainage................................................. 74 Hydrograph No. 19, Combine, Total Pre-Development North................................................ 75 Hydrograph No. 20, Combine, Total Pre-Development South................................................ 76 25 - Year Summary Report....................................................................................................................... 77 Hydrograph Reports................................................................................................................. 78 Hydrograph No. 1, Mod. Rational, Pre-Development Basin 3-Pond 3................................... 78 Hydrograph No. 2, Mod. Rational, Post-Development Basin 3-Pond 3.................................. 79 Hydrograph No. 3, Mod. Rational, Total Pre-Development Basins 4,5&8-Pond 4................. 80 Hydrograph No. 4, Mod. Rational, Tota Post-Development Basins 4,5&8-Pond 4................. 81 Hydrograph No. 5, Mod. Rational, Total Pre-Development Basins 6&9-Pond 5.................... 82 Hydrograph No. 6, Mod. Rational, Total Post-Development Basins 6&9-Pond 5................... 83 Hydrograph No. 7, Mod. Rational, Total Pre-Development Basins 7&10-Pond 6.................. 84 Hydrograph No. 8, Mod. Rational, Total Post-Development Basins 7&10-Pond 6................. 85 Hydrograph No. 9, Reservoir, Pond 3 Routed Outflow........................................................... 86 Contents continued...22147_Bikefill_Onsite_Hydraflow.gpw Hydrograph No. 10, Reservoir, Pond 5 Routed Outflow......................................................... 87 Hydrograph No. 11, Combine, Total Pond 6 Routed Inflow (P3,P5,B7&B10)........................ 88 Hydrograph No. 12, Combine, Total Pond 6 Pre-Development Inflow (B3,6,7,9,10)............. 89 Hydrograph No. 13, Reservoir, Pond 6 Routed Outflow......................................................... 90 Hydrograph No. 14, Mod. Rational, Pre-Development Basin 1-Pond 1................................. 91 Hydrograph No. 15, Mod. Rational, Pre-Development Basin 2-Pond 2................................. 92 Hydrograph No. 16, Reservoir, Pond 4 Routed Outflow......................................................... 93 Hydrograph No. 17, Mod. Rational, McIlhatten Basin 3 - Offsite............................................ 94 Hydrograph No. 18, Mod. Rational, 8-inch Culvert Drainage................................................. 95 Hydrograph No. 19, Combine, Total Pre-Development North................................................ 96 Hydrograph No. 20, Combine, Total Pre-Development South................................................ 97 50 - Year Summary Report....................................................................................................................... 98 Hydrograph Reports................................................................................................................. 99 Hydrograph No. 1, Mod. Rational, Pre-Development Basin 3-Pond 3................................... 99 Hydrograph No. 2, Mod. Rational, Post-Development Basin 3-Pond 3................................ 100 Hydrograph No. 3, Mod. Rational, Total Pre-Development Basins 4,5&8-Pond 4............... 101 Hydrograph No. 4, Mod. Rational, Tota Post-Development Basins 4,5&8-Pond 4............... 102 Hydrograph No. 5, Mod. Rational, Total Pre-Development Basins 6&9-Pond 5.................. 103 Hydrograph No. 6, Mod. Rational, Total Post-Development Basins 6&9-Pond 5................. 104 Hydrograph No. 7, Mod. Rational, Total Pre-Development Basins 7&10-Pond 6................ 105 Hydrograph No. 8, Mod. Rational, Total Post-Development Basins 7&10-Pond 6............... 106 Hydrograph No. 9, Reservoir, Pond 3 Routed Outflow......................................................... 107 Hydrograph No. 10, Reservoir, Pond 5 Routed Outflow....................................................... 108 Hydrograph No. 11, Combine, Total Pond 6 Routed Inflow (P3,P5,B7&B10)...................... 109 Hydrograph No. 12, Combine, Total Pond 6 Pre-Development Inflow (B3,6,7,9,10)........... 110 Hydrograph No. 13, Reservoir, Pond 6 Routed Outflow....................................................... 111 Hydrograph No. 14, Mod. Rational, Pre-Development Basin 1-Pond 1............................... 112 Hydrograph No. 15, Mod. Rational, Pre-Development Basin 2-Pond 2............................... 113 Hydrograph No. 16, Reservoir, Pond 4 Routed Outflow....................................................... 114 Hydrograph No. 17, Mod. Rational, McIlhatten Basin 3 - Offsite.......................................... 115 Hydrograph No. 18, Mod. Rational, 8-inch Culvert Drainage............................................... 116 Hydrograph No. 19, Combine, Total Pre-Development North.............................................. 117 Hydrograph No. 20, Combine, Total Pre-Development South.............................................. 118 100 - Year Summary Report..................................................................................................................... 119 Hydrograph Reports............................................................................................................... 120 Hydrograph No. 1, Mod. Rational, Pre-Development Basin 3-Pond 3................................. 120 Hydrograph No. 2, Mod. Rational, Post-Development Basin 3-Pond 3................................ 121 Hydrograph No. 3, Mod. Rational, Total Pre-Development Basins 4,5&8-Pond 4............... 122 Hydrograph No. 4, Mod. Rational, Tota Post-Development Basins 4,5&8-Pond 4............... 123 Hydrograph No. 5, Mod. Rational, Total Pre-Development Basins 6&9-Pond 5.................. 124 Hydrograph No. 6, Mod. Rational, Total Post-Development Basins 6&9-Pond 5................. 125 Hydrograph No. 7, Mod. Rational, Total Pre-Development Basins 7&10-Pond 6................ 126 Hydrograph No. 8, Mod. Rational, Total Post-Development Basins 7&10-Pond 6............... 127 Hydrograph No. 9, Reservoir, Pond 3 Routed Outflow......................................................... 128 Hydrograph No. 10, Reservoir, Pond 5 Routed Outflow....................................................... 129 Hydrograph No. 11, Combine, Total Pond 6 Routed Inflow (P3,P5,B7&B10)...................... 130 Contents continued...22147_Bikefill_Onsite_Hydraflow.gpw Hydrograph No. 12, Combine, Total Pond 6 Pre-Development Inflow (B3,6,7,9,10)........... 131 Hydrograph No. 13, Reservoir, Pond 6 Routed Outflow....................................................... 132 Hydrograph No. 14, Mod. Rational, Pre-Development Basin 1-Pond 1............................... 133 Hydrograph No. 15, Mod. Rational, Pre-Development Basin 2-Pond 2............................... 134 Hydrograph No. 16, Reservoir, Pond 4 Routed Outflow....................................................... 135 Hydrograph No. 17, Mod. Rational, McIlhatten Basin 3 - Offsite.......................................... 136 Hydrograph No. 18, Mod. Rational, 8-inch Culvert Drainage............................................... 137 Hydrograph No. 19, Combine, Total Pre-Development North.............................................. 138 Hydrograph No. 20, Combine, Total Pre-Development South.............................................. 139 IDF Report................................................................................................................ 140 Hydrograph Return Period Recap 1 Hyd. Hydrograph Inflow Peak Outflow (cfs) Hydrograph No. type hyd(s) Description (origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr 1 Mod. Rational ------ ------- 0.281 ------- 0.423 0.516 0.636 0.726 0.816 Pre-Development Basin 3-Pond 3 2 Mod. Rational ------ ------- 0.695 ------- 1.049 1.284 1.581 1.802 2.026 Post-Development Basin 3-Pond 3 3 Mod. Rational ------ ------- 0.412 ------- 0.619 0.755 0.931 1.063 1.194 Total Pre-Development Basins 4,5&8- 4 Mod. Rational ------ ------- 0.692 ------- 1.042 1.272 1.567 1.789 2.010 Tota Post-Development Basins 4,5&8 5 Mod. Rational ------ ------- 0.083 ------- 0.124 0.151 0.186 0.213 0.239 Total Pre-Development Basins 6&9-P 6 Mod. Rational ------ ------- 0.186 ------- 0.281 0.344 0.423 0.482 0.542 Total Post-Development Basins 6&9- 7 Mod. Rational ------ ------- 0.099 ------- 0.149 0.181 0.223 0.255 0.287 Total Pre-Development Basins 7&10- 8 Mod. Rational ------ ------- 0.273 ------- 0.378 0.428 0.527 0.649 0.730 Total Post-Development Basins 7&10 9 Reservoir 2 ------- 0.000 ------- 0.000 0.000 0.164 0.492 0.808 Pond 3 Routed Outflow 10 Reservoir 6 ------- 0.000 ------- 0.000 0.125 0.185 0.206 0.231 Pond 5 Routed Outflow 11 Combine 8, 9, 10 ------- 0.273 ------- 0.378 0.553 0.712 0.856 1.047 Total Pond 6 Routed Inflow (P3,P5,B 12 Combine 1, 5, 7, ------- 0.396 ------- 0.596 0.727 0.896 1.023 1.149 Total Pond 6 Pre-Development Inflow 13 Reservoir 11 ------- 0.000 ------- 0.337 0.499 0.644 0.724 0.851 Pond 6 Routed Outflow 14 Mod. Rational ------ ------- 0.025 ------- 0.038 0.047 0.057 0.066 0.074 Pre-Development Basin 1-Pond 1 15 Mod. Rational ------ ------- 0.020 ------- 0.029 0.036 0.044 0.050 0.057 Pre-Development Basin 2-Pond 2 16 Reservoir 4 ------- 0.000 ------- 0.000 0.259 0.699 0.901 1.032 Pond 4 Routed Outflow 17 Mod. Rational ------ ------- 0.239 ------- 0.363 0.446 0.548 0.624 0.701 McIlhatten Basin 3 - Offsite 18 Mod. Rational ------ ------- 0.060 ------- 0.091 0.112 0.138 0.157 0.176 8-inch Culvert Drainage 19 Combine 3, 14, ------- 0.431 ------- 0.648 0.791 0.975 1.113 1.250 Total Pre-Development North 20 Combine 1, 5, 7, 15, ------- 0.402 ------- 0.604 0.736 0.907 1.037 1.164 Total Pre-Development South Proj. file: 22147_Bikefill_Onsite_Hydraflow.gpw Tuesday, 08 / 18 / 2026 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hydrograph Summary Report 2 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 Mod. Rational 0.281 1 26 439 ------ ------ ------ Pre-Development Basin 3-Pond 3 2 Mod. Rational 0.695 1 25 1,470 ------ ------ ------ Post-Development Basin 3-Pond 3 3 Mod. Rational 0.412 1 26 642 ------ ------ ------ Total Pre-Development Basins 4,5&8- 4 Mod. Rational 0.692 1 26 1,166 ------ ------ ------ Tota Post-Development Basins 4,5&8 5 Mod. Rational 0.083 1 18 89 ------ ------ ------ Total Pre-Development Basins 6&9-P 6 Mod. Rational 0.186 1 5 391 ------ ------ ------ Total Post-Development Basins 6&9- 7 Mod. Rational 0.099 1 20 119 ------ ------ ------ Total Pre-Development Basins 7&10- 8 Mod. Rational 0.273 1 5 574 ------ ------ ------ Total Post-Development Basins 7&10 9 Reservoir 0.000 1 n/a 0 2 4697.03 1,460 Pond 3 Routed Outflow 10 Reservoir 0.000 1 n/a 0 6 4699.65 391 Pond 5 Routed Outflow 11 Combine 0.273 1 5 574 8, 9, 10 ------ ------ Total Pond 6 Routed Inflow (P3,P5,B 12 Combine 0.396 1 26 646 1, 5, 7, ------ ------ Total Pond 6 Pre-Development Inflow 13 Reservoir 0.000 1 n/a 0 11 4692.46 574 Pond 6 Routed Outflow 14 Mod. Rational 0.025 1 21 32 ------ ------ ------ Pre-Development Basin 1-Pond 1 15 Mod. Rational 0.020 1 15 18 ------ ------ ------ Pre-Development Basin 2-Pond 2 16 Reservoir 0.000 1 n/a 0 4 4693.26 1,163 Pond 4 Routed Outflow 17 Mod. Rational 0.239 1 5 72 ------ ------ ------ McIlhatten Basin 3 - Offsite 18 Mod. Rational 0.060 1 5 18 ------ ------ ------ 8-inch Culvert Drainage 19 Combine 0.431 1 26 674 3, 14, ------ ------ Total Pre-Development North 20 Combine 0.402 1 20 664 1, 5, 7, 15, ------ ------ Total Pre-Development South 22147_Bikefill_Onsite_Hydraflow.gpw Return Period: 2 Year Tuesday, 08 / 18 / 2026 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 1 Pre-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 0.281 cfs Storm frequency = 2 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 439 cuft Drainage area = 1.680 ac Runoff coeff. = 0.2 Intensity = 0.837 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 3 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Pre-Development Basin 3-Pond 3 Hyd. No. 1 -- 2 Year Hyd No. 1 TR55 Tc Worksheet 4 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hyd. No. 1 Pre-Development Basin 3-Pond 3 Description A B C Totals Sheet Flow Manning's n-value = 0.240 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 1.18 0.00 0.00 Land slope (%) = 3.60 0.00 0.00 Travel Time (min) = 25.69 + 0.00 + 0.00 = 25.69 Shallow Concentrated Flow Flow length (ft) = 175.00 0.00 0.00 Watercourse slope (%) = 6.80 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =4.21 0.00 0.00 Travel Time (min) = 0.69 + 0.00 + 0.00 = 0.69 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 26.00 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 2 Post-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 0.695 cfs Storm frequency = 2 yrs Time to peak = 25 min Time interval = 1 min Hyd. volume = 1,470 cuft Drainage area = 1.680 ac Runoff coeff. = 0.627 Intensity = 0.660 in/hr Tc by TR55 = 25.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.4 x Tc Target Q =0.280 cfs Est. Req'd Storage =953 cuft 5 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Post-Development Basin 3-Pond 3 Hyd. No. 2 -- 2 Year Hyd No. 2 Mod. Rational Est. Storage = 953 cuft TR55 Tc Worksheet 6 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hyd. No. 2 Post-Development Basin 3-Pond 3 Description A B C Totals Sheet Flow Manning's n-value = 0.240 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 1.18 0.00 0.00 Land slope (%) = 5.00 0.00 0.00 Travel Time (min) = 22.53 + 0.00 + 0.00 = 22.53 Shallow Concentrated Flow Flow length (ft) = 376.00 115.10 0.00 Watercourse slope (%) = 2.97 4.86 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =2.78 4.48 0.00 Travel Time (min) = 2.25 + 0.43 + 0.00 = 2.68 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 25.00 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 3 Total Pre-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 0.412 cfs Storm frequency = 2 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 642 cuft Drainage area = 1.230 ac Runoff coeff. = 0.4 Intensity = 0.837 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 7 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 4,5&8-Pond 4 Hyd. No. 3 -- 2 Year Hyd No. 3 TR55 Tc Worksheet 8 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hyd. No. 3 Total Pre-Development Basins 4,5&8-Pond 4 Description A B C Totals Sheet Flow Manning's n-value = 0.240 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 1.18 0.00 0.00 Land slope (%) = 3.90 0.00 0.00 Travel Time (min) = 24.88 + 0.00 + 0.00 = 24.88 Shallow Concentrated Flow Flow length (ft) = 276.90 0.00 0.00 Watercourse slope (%) = 4.60 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =3.46 0.00 0.00 Travel Time (min) = 1.33 + 0.00 + 0.00 = 1.33 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 26.00 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 4 Tota Post-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 0.692 cfs Storm frequency = 2 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,166 cuft Drainage area = 1.230 ac Runoff coeff. = 0.713 Intensity = 0.789 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.1 x Tc Target Q =0.410 cfs Est. Req'd Storage =498 cuft 9 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Tota Post-Development Basins 4,5&8-Pond 4 Hyd. No. 4 -- 2 Year Hyd No. 4 Mod. Rational Est. Storage = 498 cuft TR55 Tc Worksheet 10 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hyd. No. 4 Tota Post-Development Basins 4,5&8-Pond 4 Description A B C Totals Sheet Flow Manning's n-value = 0.240 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 1.18 0.00 0.00 Land slope (%) = 3.90 0.00 0.00 Travel Time (min) = 24.88 + 0.00 + 0.00 = 24.88 Shallow Concentrated Flow Flow length (ft) = 116.92 199.42 0.00 Watercourse slope (%) = 3.60 3.69 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =3.06 3.90 0.00 Travel Time (min) = 0.64 + 0.85 + 0.00 = 1.49 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 26.00 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 5 Total Pre-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.083 cfs Storm frequency = 2 yrs Time to peak = 18 min Time interval = 1 min Hyd. volume = 89 cuft Drainage area = 0.380 ac Runoff coeff. = 0.2 Intensity = 1.086 in/hr Tc by TR55 = 18.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 11 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Total Pre-Development Basins 6&9-Pond 5 Hyd. No. 5 -- 2 Year Hyd No. 5 TR55 Tc Worksheet 12 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hyd. No. 5 Total Pre-Development Basins 6&9-Pond 5 Description A B C Totals Sheet Flow Manning's n-value = 0.240 0.011 0.011 Flow length (ft) = 150.0 0.0 0.0 Two-year 24-hr precip. (in) = 1.18 0.00 0.00 Land slope (%) = 8.60 0.00 0.00 Travel Time (min) = 18.14 + 0.00 + 0.00 = 18.14 Shallow Concentrated Flow Flow length (ft) = 7.70 0.00 0.00 Watercourse slope (%) = 4.00 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =3.23 0.00 0.00 Travel Time (min) = 0.04 + 0.00 + 0.00 = 0.04 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 18.00 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 6 Total Post-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.186 cfs Storm frequency = 2 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 391 cuft Drainage area = 0.380 ac Runoff coeff. = 0.738 Intensity = 0.664 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.0 x Tc Target Q =0.080 cfs Est. Req'd Storage =294 cuft 13 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Post-Development Basins 6&9-Pond 5 Hyd. No. 6 -- 2 Year Hyd No. 6 Mod. Rational Est. Storage = 294 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 7 Total Pre-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.099 cfs Storm frequency = 2 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 119 cuft Drainage area = 0.490 ac Runoff coeff. = 0.2 Intensity = 1.011 in/hr Tc by TR55 = 20.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 14 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Total Pre-Development Basins 7&10-Pond 6 Hyd. No. 7 -- 2 Year Hyd No. 7 TR55 Tc Worksheet 15 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hyd. No. 7 Total Pre-Development Basins 7&10-Pond 6 Description A B C Totals Sheet Flow Manning's n-value = 0.240 0.011 0.011 Flow length (ft) = 142.0 0.0 0.0 Two-year 24-hr precip. (in) = 1.18 0.00 0.00 Land slope (%) = 5.90 0.00 0.00 Travel Time (min) = 20.18 + 0.00 + 0.00 = 20.18 Shallow Concentrated Flow Flow length (ft) = 0.00 0.00 0.00 Watercourse slope (%) = 0.00 0.00 0.00 Surface description = Paved Paved Paved Average velocity (ft/s) =0.00 0.00 0.00 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 20.00 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 8 Total Post-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.273 cfs Storm frequency = 2 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 574 cuft Drainage area = 0.490 ac Runoff coeff. = 0.84 Intensity = 0.664 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.0 x Tc Target Q =0.100 cfs Est. Req'd Storage =451 cuft 16 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Post-Development Basins 7&10-Pond 6 Hyd. No. 8 -- 2 Year Hyd No. 8 Mod. Rational Est. Storage = 451 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 9 Pond 3 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 2 - Post-Development Basin 3-Pond 3Max. Elevation = 4697.03 ft Reservoir name = POND 3 Max. Storage = 1,460 cuft Storage Indication method used. 17 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pond 3 Routed Outflow Hyd. No. 9 -- 2 Year Hyd No. 9 Hyd No. 2 Total storage used = 1,460 cuft Pond Report 18 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Pond No. 2 - POND 3 Pond Data UG Chambers -Invert elev. = 4695.50 ft, Rise x Span = 2.44 x 3.71 ft, Barrel Len = 7.12 ft, No. Barrels = 29, Slope = 0.00%, Headers = No Encasement -Invert elev. = 4695.00 ft, Width = 5.58 ft, Height = 3.75 ft, Voids = 30.00%Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 4700.73 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4695.00 n/a 0 0 0.38 4695.38 n/a 130 130 0.75 4695.75 n/a 263 393 1.13 4696.13 n/a 327 720 1.50 4696.50 n/a 319 1,039 1.88 4696.88 n/a 305 1,345 2.25 4697.25 n/a 284 1,628 2.63 4697.63 n/a 251 1,879 3.00 4698.00 n/a 186 2,065 3.38 4698.38 n/a 130 2,195 3.75 4698.75 n/a 130 2,324 5.73 4700.73 04 3 2,327 6.23 4701.23 141 28 2,355 6.73 4701.73 318 112 2,467 7.23 4702.23 564 217 2,684 7.70 4702.70 860 332 3,016 8.28 4703.28 1,318 627 3,643 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)Inactive Inactive Inactive 0.00 Span (in)= 0.00 0.00 0.00 0.00 No. Barrels = 0 0 0 0 Invert El. (ft)= 0.00 0.00 0.00 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.60 Inactive Inactive 0.00 Crest El. (ft)= 4702.73 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = Rect --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 0.000 (by Contour) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 4695.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.38 130 4695.38 --- --- --- --- 0.00 --- --- --- --- --- 0.000 0.75 393 4695.75 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.13 720 4696.13 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.50 1,039 4696.50 --- --- --- --- 0.00 --- --- --- --- --- 0.000 1.88 1,345 4696.88 --- --- --- --- 0.00 --- --- --- --- --- 0.000 2.25 1,628 4697.25 --- --- --- --- 0.00 --- --- --- --- --- 0.000 2.63 1,879 4697.63 --- --- --- --- 0.00 --- --- --- --- --- 0.000 3.00 2,065 4698.00 --- --- --- --- 0.00 --- --- --- --- --- 0.000 3.38 2,195 4698.38 --- --- --- --- 0.00 --- --- --- --- --- 0.000 3.75 2,324 4698.75 --- --- --- --- 0.00 --- --- --- --- --- 0.000 5.73 2,327 4700.73 --- --- --- --- 0.00 --- --- --- --- --- 0.000 6.23 2,355 4701.23 --- --- --- --- 0.00 --- --- --- --- --- 0.000 6.73 2,467 4701.73 --- --- --- --- 0.00 --- --- --- --- --- 0.000 7.23 2,684 4702.23 --- --- --- --- 0.00 --- --- --- --- --- 0.000 7.70 3,016 4702.70 --- --- --- --- 0.00 --- --- --- --- --- 0.000 8.28 3,643 4703.28 --- --- --- --- 0.81 --- --- --- --- --- 0.815 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 10 Pond 5 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 6 - Total Post-Development Basins 6&9-Pond 5Max. Elevation = 4699.65 ft Reservoir name = POND 5 Max. Storage = 391 cuft Storage Indication method used. 19 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Pond 5 Routed Outflow Hyd. No. 10 -- 2 Year Hyd No. 10 Hyd No. 6 Total storage used = 391 cuft Pond Report 20 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Pond No. 1 - POND 5 Pond Data Pond storage is based on user-defined values. Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4698.20 n/a 0 0 0.50 4698.70 n/a 135 135 1.00 4699.20 n/a 135 270 1.50 4699.70 n/a 135 405 2.00 4700.20 n/a 135 540 2.50 4700.70 n/a 135 675 2.96 4701.16 n/a 9 684 3.46 4701.66 n/a 45 729 3.96 4702.16 n/a 107 836 4.30 4702.50 n/a 122 958 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 2.00 1.50 1.00 Inactive Span (in)= 2.00 1.50 1.00 0.00 No. Barrels = 1 1 1 1 Invert El. (ft)= 4700.49 4700.80 4702.30 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)Inactive Inactive Inactive Inactive Crest El. (ft)= 4702.50 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = Rect --- --- --- Multi-Stage = Yes No No No Exfil.(in/hr)= 0.000 (by Wet area) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 4698.20 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 0.50 135 4698.70 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 1.00 270 4699.20 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 1.50 405 4699.70 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 2.00 540 4700.20 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 2.50 675 4700.70 0.04 ic 0.00 0.00 --- 0.00 --- --- --- --- ---0.038 2.96 684 4701.16 0.08 ic 0.03 ic 0.00 --- 0.00 --- --- --- ------ 0.113 3.46 729 4701.66 0.11 ic 0.05 ic 0.00 --- 0.00 --- --- --- ------ 0.162 3.96 836 4702.16 0.13 ic 0.07 ic 0.00 --- 0.00 --- --- --- ------ 0.200 4.30 958 4702.50 0.15 ic 0.08 ic 0.01 ic --- 0.00 --- --- ------ --- 0.232 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 11 Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hydrograph type = Combine Peak discharge = 0.273 cfs Storm frequency = 2 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 574 cuft Inflow hyds. = 8, 9, 10 Contrib. drain. area = 0.490 ac 21 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hyd. No. 11 -- 2 Year Hyd No. 11 Hyd No. 8 Hyd No. 9 Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 12 Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hydrograph type = Combine Peak discharge = 0.396 cfs Storm frequency = 2 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 646 cuft Inflow hyds. = 1, 5, 7 Contrib. drain. area = 2.550 ac 22 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hyd. No. 12 -- 2 Year Hyd No. 12 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 13 Pond 6 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 11 - Total Pond 6 Routed Inflow (P3,P5,B7&B10)Max. Elevation = 4692.46 ft Reservoir name = POND 6 Max. Storage = 574 cuft Storage Indication method used. 23 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Pond 6 Routed Outflow Hyd. No. 13 -- 2 Year Hyd No. 13 Hyd No. 11 Total storage used = 574 cuft Pond Report 24 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Pond No. 4 - POND 6 Pond Data Pond storage is based on user-defined values. Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4689.91 n/a 0 0 0.50 4690.41 n/a 113 113 1.00 4690.91 n/a 113 225 1.50 4691.41 n/a 113 338 2.00 4691.91 n/a 113 450 2.50 4692.41 n/a 113 563 3.00 4692.91 n/a 113 675 3.50 4693.41 n/a 113 788 6.00 4695.91 n/a 2 789 6.50 4696.41 n/a 11 800 7.00 4696.91 n/a 30 830 7.50 4697.41 n/a 59 889 8.00 4697.91 n/a 97 986 8.50 4698.41 n/a 145 1,131 9.00 4698.91 n/a 207 1,339 9.50 4699.41 n/a 293 1,632 9.70 4699.61 n/a 141 1,774 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 4.00 2.00 1.00 0.00 Span (in)= 4.00 2.00 1.00 0.00 No. Barrels = 1 1 1 0 Invert El. (ft)= 4695.61 4696.79 4698.14 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)= 0.00 0.00 0.00 0.00 Crest El. (ft)= 0.00 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = --- --- --- --- Multi-Stage = No No No No Exfil.(in/hr)= 0.000 (by Wet area) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 4689.91 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 0.50 113 4690.41 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 1.00 225 4690.91 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 1.50 338 4691.41 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 2.00 450 4691.91 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 2.50 563 4692.41 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 3.00 675 4692.91 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 3.50 788 4693.41 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 6.00 789 4695.91 0.15 ic 0.00 0.00 --- --- --- --- --- --- --- 0.154 6.50 800 4696.41 0.33 ic 0.00 0.00 --- --- --- --- --- --- --- 0.334 7.00 830 4696.91 0.45 ic 0.02 ic 0.00 --- --- --- --- --- --- --- 0.468 7.50 889 4697.41 0.54 ic 0.08 ic 0.00 --- --- --- --- --- --- --- 0.614 8.00 986 4697.91 0.61 ic 0.11 ic 0.00 --- --- --- --- --- --- --- 0.721 8.50 1,131 4698.41 0.68 ic 0.13 ic 0.01 ic --- --- --- --- --- --- --- 0.825 9.00 1,339 4698.91 0.74 ic 0.15 ic 0.02 ic --- --- --- --- --- --- --- 0.916 9.50 1,632 4699.41 0.80 ic 0.17 ic 0.03 ic --- --- --- --- --- --- --- 0.997 9.70 1,774 4699.61 0.82 ic 0.17 ic 0.03 ic --- --- --- --- --- --- --- 1.028 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 14 Pre-Development Basin 1-Pond 1 Hydrograph type = Mod. Rational Peak discharge = 0.025 cfs Storm frequency = 2 yrs Time to peak = 21 min Time interval = 1 min Hyd. volume = 32 cuft Drainage area = 0.130 ac Runoff coeff. = 0.2 Intensity = 0.977 in/hr Tc by TR55 = 21.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 25 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 1-Pond 1 Hyd. No. 14 -- 2 Year Hyd No. 14 TR55 Tc Worksheet 26 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hyd. No. 14 Pre-Development Basin 1-Pond 1 Description A B C Totals Sheet Flow Manning's n-value = 0.240 0.011 0.011 Flow length (ft) = 101.5 0.0 0.0 Two-year 24-hr precip. (in) = 1.18 0.00 0.00 Land slope (%) = 2.86 0.00 0.00 Travel Time (min) = 20.61 + 0.00 + 0.00 = 20.61 Shallow Concentrated Flow Flow length (ft) = 0.00 0.00 0.00 Watercourse slope (%) = 0.00 0.00 0.00 Surface description = Paved Paved Paved Average velocity (ft/s) =0.00 0.00 0.00 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 21.00 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 15 Pre-Development Basin 2-Pond 2 Hydrograph type = Mod. Rational Peak discharge = 0.020 cfs Storm frequency = 2 yrs Time to peak = 15 min Time interval = 1 min Hyd. volume = 18 cuft Drainage area = 0.080 ac Runoff coeff. = 0.2 Intensity = 1.221 in/hr Tc by TR55 = 15.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 27 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 2-Pond 2 Hyd. No. 15 -- 2 Year Hyd No. 15 TR55 Tc Worksheet 28 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hyd. No. 15 Pre-Development Basin 2-Pond 2 Description A B C Totals Sheet Flow Manning's n-value = 0.240 0.011 0.011 Flow length (ft) = 74.8 0.0 0.0 Two-year 24-hr precip. (in) = 1.18 0.00 0.00 Land slope (%) = 3.61 0.00 0.00 Travel Time (min) = 14.70 + 0.00 + 0.00 = 14.70 Shallow Concentrated Flow Flow length (ft) = 0.00 0.00 0.00 Watercourse slope (%) = 0.00 0.00 0.00 Surface description = Paved Paved Paved Average velocity (ft/s) =0.00 0.00 0.00 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) =0.00 0.00 0.00 Flow length (ft) ({0})0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc .............................................................................. 15.00 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 16 Pond 4 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 2 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 4 - Tota Post-Development Basins 4,5&8-Pond 4Max. Elevation = 4693.26 ft Reservoir name = POND 4 Max. Storage = 1,163 cuft Storage Indication method used. 29 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pond 4 Routed Outflow Hyd. No. 16 -- 2 Year Hyd No. 16 Hyd No. 4 Total storage used = 1,163 cuft Pond Report 30 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Pond No. 3 - POND 4 Pond Data UG Chambers -Invert elev. = 4692.25 ft, Rise x Span = 2.44 x 3.71 ft, Barrel Len = 7.12 ft, No. Barrels = 20, Slope = 0.00%, Headers = No Encasement -Invert elev. = 4690.00 ft, Width = 5.77 ft, Height = 5.50 ft, Voids = 30.00%Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 4699.50 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 4690.00 n/a 0 0 0.55 4690.55 n/a 136 136 1.10 4691.10 n/a 136 271 1.65 4691.65 n/a 136 407 2.20 4692.20 n/a 136 542 2.75 4692.75 n/a 319 862 3.30 4693.30 n/a 328 1,190 3.85 4693.85 n/a 306 1,495 4.40 4694.40 n/a 264 1,759 4.95 4694.95 n/a 170 1,929 5.50 4695.50 n/a 136 2,065 9.50 4699.50 02 3 2,067 10.00 4700.00 32 7 2,074 10.50 4700.50 84 28 2,102 11.00 4701.00 159 60 2,162 11.50 4701.50 261 104 2,266 12.00 4702.00 393 162 2,429 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 5.00 2.00 0.50 0.00 Span (in)= 5.00 2.00 0.50 0.00 No. Barrels = 1 1 1 0 Invert El. (ft)= 4699.70 4701.00 4701.50 0.00 Length (ft)= 0.00 0.00 0.00 0.00 Slope (%)= 0.00 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No Crest Len (ft)Inactive 0.00 0.00 0.00 Crest El. (ft)= 0.00 0.00 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = 1 --- --- --- Multi-Stage = Yes No No No Exfil.(in/hr)= 0.000 (by Wet area) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 4690.00 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 0.55 136 4690.55 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 1.10 271 4691.10 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 1.65 407 4691.65 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 2.20 542 4692.20 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 2.75 862 4692.75 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 3.30 1,190 4693.30 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 3.85 1,495 4693.85 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 4.40 1,759 4694.40 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 4.95 1,929 4694.95 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 5.50 2,065 4695.50 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 9.50 2,067 4699.50 0.00 0.00 0.00 --- --- --- --- --- --- --- 0.000 10.00 2,074 4700.00 0.20 ic 0.00 0.00 --- --- --- --- --- --- --- 0.196 10.50 2,102 4700.50 0.50 ic 0.00 0.00 --- --- --- --- --- --- --- 0.505 11.00 2,162 4701.00 0.69 ic 0.00 0.00 --- --- --- --- --- --- --- 0.686 11.50 2,266 4701.50 0.83 ic 0.07 ic 0.00 --- --- --- --- --- --- --- 0.896 12.00 2,429 4702.00 0.95 ic 0.10 ic 0.00 ic --- --- --- --- --- --- --- 1.054 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 17 McIlhatten Basin 3 - Offsite Hydrograph type = Mod. Rational Peak discharge = 0.239 cfs Storm frequency = 2 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 72 cuft Drainage area = 0.180 ac Runoff coeff. = 0.64* Intensity = 2.077 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a * Composite (Area/C) = [(0.065 x 0.95) + (0.057 x 0.75) + (0.059 x 0.20)] / 0.180 31 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) McIlhatten Basin 3 - Offsite Hyd. No. 17 -- 2 Year Hyd No. 17 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 18 8-inch Culvert Drainage Hydrograph type = Mod. Rational Peak discharge = 0.060 cfs Storm frequency = 2 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 18 cuft Drainage area = 0.145 ac Runoff coeff. = 0.2 Intensity = 2.077 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 32 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) 8-inch Culvert Drainage Hyd. No. 18 -- 2 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 19 Total Pre-Development North Hydrograph type = Combine Peak discharge = 0.431 cfs Storm frequency = 2 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 674 cuft Inflow hyds. = 3, 14 Contrib. drain. area = 1.360 ac 33 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development North Hyd. No. 19 -- 2 Year Hyd No. 19 Hyd No. 3 Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 20 Total Pre-Development South Hydrograph type = Combine Peak discharge = 0.402 cfs Storm frequency = 2 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 664 cuft Inflow hyds. = 1, 5, 7, 15 Contrib. drain. area = 2.630 ac 34 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development South Hyd. No. 20 -- 2 Year Hyd No. 20 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hyd No. 15 Hydrograph Summary Report 35 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 Mod. Rational 0.423 1 26 660 ------ ------ ------ Pre-Development Basin 3-Pond 3 2 Mod. Rational 1.049 1 25 2,220 ------ ------ ------ Post-Development Basin 3-Pond 3 3 Mod. Rational 0.619 1 26 966 ------ ------ ------ Total Pre-Development Basins 4,5&8- 4 Mod. Rational 1.042 1 26 1,756 ------ ------ ------ Tota Post-Development Basins 4,5&8 5 Mod. Rational 0.124 1 18 134 ------ ------ ------ Total Pre-Development Basins 6&9-P 6 Mod. Rational 0.281 1 5 590 ------ ------ ------ Total Post-Development Basins 6&9- 7 Mod. Rational 0.149 1 20 179 ------ ------ ------ Total Pre-Development Basins 7&10- 8 Mod. Rational 0.378 1 5 885 ------ ------ ------ Total Post-Development Basins 7&10 9 Reservoir 0.000 1 n/a 0 2 4698.40 2,204 Pond 3 Routed Outflow 10 Reservoir 0.000 1 n/a 0 6 4700.38 590 Pond 5 Routed Outflow 11 Combine 0.378 1 5 885 8, 9, 10 ------ ------ Total Pond 6 Routed Inflow (P3,P5,B 12 Combine 0.596 1 26 972 1, 5, 7, ------ ------ Total Pond 6 Pre-Development Inflow 13 Reservoir 0.337 1 40 97 11 4696.42 801 Pond 6 Routed Outflow 14 Mod. Rational 0.038 1 21 48 ------ ------ ------ Pre-Development Basin 1-Pond 1 15 Mod. Rational 0.029 1 15 26 ------ ------ ------ Pre-Development Basin 2-Pond 2 16 Reservoir 0.000 1 n/a 0 4 4694.38 1,751 Pond 4 Routed Outflow 17 Mod. Rational 0.363 1 5 109 ------ ------ ------ McIlhatten Basin 3 - Offsite 18 Mod. Rational 0.091 1 5 27 ------ ------ ------ 8-inch Culvert Drainage 19 Combine 0.648 1 26 1,014 3, 14, ------ ------ Total Pre-Development North 20 Combine 0.604 1 20 999 1, 5, 7, 15, ------ ------ Total Pre-Development South 22147_Bikefill_Onsite_Hydraflow.gpw Return Period: 5 Year Tuesday, 08 / 18 / 2026 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 1 Pre-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 0.423 cfs Storm frequency = 5 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 660 cuft Drainage area = 1.680 ac Runoff coeff. = 0.2 Intensity = 1.259 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 36 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Pre-Development Basin 3-Pond 3 Hyd. No. 1 -- 5 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 2 Post-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 1.049 cfs Storm frequency = 5 yrs Time to peak = 25 min Time interval = 1 min Hyd. volume = 2,220 cuft Drainage area = 1.680 ac Runoff coeff. = 0.627 Intensity = 0.996 in/hr Tc by TR55 = 25.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.4 x Tc Target Q =0.420 cfs Est. Req'd Storage =1,442 cuft 37 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Post-Development Basin 3-Pond 3 Hyd. No. 2 -- 5 Year Hyd No. 2 Mod. Rational Est. Storage = 1,442 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 3 Total Pre-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 0.619 cfs Storm frequency = 5 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 966 cuft Drainage area = 1.230 ac Runoff coeff. = 0.4 Intensity = 1.259 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 38 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pre-Development Basins 4,5&8-Pond 4 Hyd. No. 3 -- 5 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 4 Tota Post-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 1.042 cfs Storm frequency = 5 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,756 cuft Drainage area = 1.230 ac Runoff coeff. = 0.713 Intensity = 1.188 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.1 x Tc Target Q =0.620 cfs Est. Req'd Storage =746 cuft 39 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Tota Post-Development Basins 4,5&8-Pond 4 Hyd. No. 4 -- 5 Year Hyd No. 4 Mod. Rational Est. Storage = 746 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 5 Total Pre-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.124 cfs Storm frequency = 5 yrs Time to peak = 18 min Time interval = 1 min Hyd. volume = 134 cuft Drainage area = 0.380 ac Runoff coeff. = 0.2 Intensity = 1.631 in/hr Tc by TR55 = 18.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 40 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 6&9-Pond 5 Hyd. No. 5 -- 5 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 6 Total Post-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.281 cfs Storm frequency = 5 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 590 cuft Drainage area = 0.380 ac Runoff coeff. = 0.738 Intensity = 1.002 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.0 x Tc Target Q =0.120 cfs Est. Req'd Storage =444 cuft 41 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Post-Development Basins 6&9-Pond 5 Hyd. No. 6 -- 5 Year Hyd No. 6 Mod. Rational Est. Storage = 444 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 7 Total Pre-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.149 cfs Storm frequency = 5 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 179 cuft Drainage area = 0.490 ac Runoff coeff. = 0.2 Intensity = 1.519 in/hr Tc by TR55 = 20.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 42 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 7&10-Pond 6 Hyd. No. 7 -- 5 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 8 Total Post-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.378 cfs Storm frequency = 5 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 885 cuft Drainage area = 0.490 ac Runoff coeff. = 0.84 Intensity = 0.919 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.8 x Tc Target Q =0.150 cfs Est. Req'd Storage =683 cuft 43 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Post-Development Basins 7&10-Pond 6 Hyd. No. 8 -- 5 Year Hyd No. 8 Mod. Rational Est. Storage = 683 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 9 Pond 3 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 5 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 2 - Post-Development Basin 3-Pond 3Max. Elevation = 4698.40 ft Reservoir name = POND 3 Max. Storage = 2,204 cuft Storage Indication method used. 44 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Pond 3 Routed Outflow Hyd. No. 9 -- 5 Year Hyd No. 9 Hyd No. 2 Total storage used = 2,204 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 10 Pond 5 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 5 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 6 - Total Post-Development Basins 6&9-Pond 5Max. Elevation = 4700.38 ft Reservoir name = POND 5 Max. Storage = 590 cuft Storage Indication method used. 45 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Pond 5 Routed Outflow Hyd. No. 10 -- 5 Year Hyd No. 10 Hyd No. 6 Total storage used = 590 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 11 Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hydrograph type = Combine Peak discharge = 0.378 cfs Storm frequency = 5 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 885 cuft Inflow hyds. = 8, 9, 10 Contrib. drain. area = 0.490 ac 46 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hyd. No. 11 -- 5 Year Hyd No. 11 Hyd No. 8 Hyd No. 9 Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 12 Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hydrograph type = Combine Peak discharge = 0.596 cfs Storm frequency = 5 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 972 cuft Inflow hyds. = 1, 5, 7 Contrib. drain. area = 2.550 ac 47 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hyd. No. 12 -- 5 Year Hyd No. 12 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 13 Pond 6 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.337 cfs Storm frequency = 5 yrs Time to peak = 40 min Time interval = 1 min Hyd. volume = 97 cuft Inflow hyd. No. = 11 - Total Pond 6 Routed Inflow (P3,P5,B7&B10)Max. Elevation = 4696.42 ft Reservoir name = POND 6 Max. Storage = 801 cuft Storage Indication method used. 48 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Pond 6 Routed Outflow Hyd. No. 13 -- 5 Year Hyd No. 13 Hyd No. 11 Total storage used = 801 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 14 Pre-Development Basin 1-Pond 1 Hydrograph type = Mod. Rational Peak discharge = 0.038 cfs Storm frequency = 5 yrs Time to peak = 21 min Time interval = 1 min Hyd. volume = 48 cuft Drainage area = 0.130 ac Runoff coeff. = 0.2 Intensity = 1.468 in/hr Tc by TR55 = 21.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 49 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 1-Pond 1 Hyd. No. 14 -- 5 Year Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 15 Pre-Development Basin 2-Pond 2 Hydrograph type = Mod. Rational Peak discharge = 0.029 cfs Storm frequency = 5 yrs Time to peak = 15 min Time interval = 1 min Hyd. volume = 26 cuft Drainage area = 0.080 ac Runoff coeff. = 0.2 Intensity = 1.835 in/hr Tc by TR55 = 15.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 50 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 2-Pond 2 Hyd. No. 15 -- 5 Year Hyd No. 15 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 16 Pond 4 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 5 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 4 - Tota Post-Development Basins 4,5&8-Pond 4Max. Elevation = 4694.38 ft Reservoir name = POND 4 Max. Storage = 1,751 cuft Storage Indication method used. 51 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Pond 4 Routed Outflow Hyd. No. 16 -- 5 Year Hyd No. 16 Hyd No. 4 Total storage used = 1,751 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 17 McIlhatten Basin 3 - Offsite Hydrograph type = Mod. Rational Peak discharge = 0.363 cfs Storm frequency = 5 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 109 cuft Drainage area = 0.180 ac Runoff coeff. = 0.64* Intensity = 3.153 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a * Composite (Area/C) = [(0.065 x 0.95) + (0.057 x 0.75) + (0.059 x 0.20)] / 0.180 52 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) McIlhatten Basin 3 - Offsite Hyd. No. 17 -- 5 Year Hyd No. 17 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 18 8-inch Culvert Drainage Hydrograph type = Mod. Rational Peak discharge = 0.091 cfs Storm frequency = 5 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 27 cuft Drainage area = 0.145 ac Runoff coeff. = 0.2 Intensity = 3.153 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 53 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) 8-inch Culvert Drainage Hyd. No. 18 -- 5 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 19 Total Pre-Development North Hydrograph type = Combine Peak discharge = 0.648 cfs Storm frequency = 5 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,014 cuft Inflow hyds. = 3, 14 Contrib. drain. area = 1.360 ac 54 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pre-Development North Hyd. No. 19 -- 5 Year Hyd No. 19 Hyd No. 3 Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 20 Total Pre-Development South Hydrograph type = Combine Peak discharge = 0.604 cfs Storm frequency = 5 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 999 cuft Inflow hyds. = 1, 5, 7, 15 Contrib. drain. area = 2.630 ac 55 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pre-Development South Hyd. No. 20 -- 5 Year Hyd No. 20 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hyd No. 15 Hydrograph Summary Report 56 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 Mod. Rational 0.516 1 26 805 ------ ------ ------ Pre-Development Basin 3-Pond 3 2 Mod. Rational 1.284 1 25 2,716 ------ ------ ------ Post-Development Basin 3-Pond 3 3 Mod. Rational 0.755 1 26 1,178 ------ ------ ------ Total Pre-Development Basins 4,5&8- 4 Mod. Rational 1.272 1 26 2,143 ------ ------ ------ Tota Post-Development Basins 4,5&8 5 Mod. Rational 0.151 1 18 163 ------ ------ ------ Total Pre-Development Basins 6&9-P 6 Mod. Rational 0.344 1 5 722 ------ ------ ------ Total Post-Development Basins 6&9- 7 Mod. Rational 0.181 1 20 218 ------ ------ ------ Total Pre-Development Basins 7&10- 8 Mod. Rational 0.428 1 5 1,105 ------ ------ ------ Total Post-Development Basins 7&10 9 Reservoir 0.000 1 n/a 0 2 4702.25 2,696 Pond 3 Routed Outflow 10 Reservoir 0.125 1 38 99 6 4701.26 693 Pond 5 Routed Outflow 11 Combine 0.553 1 38 1,204 8, 9, 10 ------ ------ Total Pond 6 Routed Inflow (P3,P5,B 12 Combine 0.727 1 26 1,185 1, 5, 7, ------ ------ Total Pond 6 Pre-Development Inflow 13 Reservoir 0.499 1 41 415 11 4696.99 840 Pond 6 Routed Outflow 14 Mod. Rational 0.047 1 21 59 ------ ------ ------ Pre-Development Basin 1-Pond 1 15 Mod. Rational 0.036 1 15 32 ------ ------ ------ Pre-Development Basin 2-Pond 2 16 Reservoir 0.259 1 49 66 4 4700.06 2,078 Pond 4 Routed Outflow 17 Mod. Rational 0.446 1 5 134 ------ ------ ------ McIlhatten Basin 3 - Offsite 18 Mod. Rational 0.112 1 5 34 ------ ------ ------ 8-inch Culvert Drainage 19 Combine 0.791 1 26 1,237 3, 14, ------ ------ Total Pre-Development North 20 Combine 0.736 1 26 1,218 1, 5, 7, 15, ------ ------ Total Pre-Development South 22147_Bikefill_Onsite_Hydraflow.gpw Return Period: 10 Year Tuesday, 08 / 18 / 2026 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 1 Pre-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 0.516 cfs Storm frequency = 10 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 805 cuft Drainage area = 1.680 ac Runoff coeff. = 0.2 Intensity = 1.535 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 57 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pre-Development Basin 3-Pond 3 Hyd. No. 1 -- 10 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 2 Post-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 1.284 cfs Storm frequency = 10 yrs Time to peak = 25 min Time interval = 1 min Hyd. volume = 2,716 cuft Drainage area = 1.680 ac Runoff coeff. = 0.627 Intensity = 1.219 in/hr Tc by TR55 = 25.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.4 x Tc Target Q =0.520 cfs Est. Req'd Storage =1,755 cuft 58 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Post-Development Basin 3-Pond 3 Hyd. No. 2 -- 10 Year Hyd No. 2 Mod. Rational Est. Storage = 1,755 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 3 Total Pre-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 0.755 cfs Storm frequency = 10 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,178 cuft Drainage area = 1.230 ac Runoff coeff. = 0.4 Intensity = 1.535 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 59 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pre-Development Basins 4,5&8-Pond 4 Hyd. No. 3 -- 10 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 4 Tota Post-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 1.272 cfs Storm frequency = 10 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 2,143 cuft Drainage area = 1.230 ac Runoff coeff. = 0.713 Intensity = 1.450 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.1 x Tc Target Q =0.750 cfs Est. Req'd Storage =918 cuft 60 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Tota Post-Development Basins 4,5&8-Pond 4 Hyd. No. 4 -- 10 Year Hyd No. 4 Mod. Rational Est. Storage = 918 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 5 Total Pre-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.151 cfs Storm frequency = 10 yrs Time to peak = 18 min Time interval = 1 min Hyd. volume = 163 cuft Drainage area = 0.380 ac Runoff coeff. = 0.2 Intensity = 1.986 in/hr Tc by TR55 = 18.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 61 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 6&9-Pond 5 Hyd. No. 5 -- 10 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 6 Total Post-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.344 cfs Storm frequency = 10 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 722 cuft Drainage area = 0.380 ac Runoff coeff. = 0.738 Intensity = 1.226 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.0 x Tc Target Q =0.150 cfs Est. Req'd Storage =539 cuft 62 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Post-Development Basins 6&9-Pond 5 Hyd. No. 6 -- 10 Year Hyd No. 6 Mod. Rational Est. Storage = 539 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 7 Total Pre-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.181 cfs Storm frequency = 10 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 218 cuft Drainage area = 0.490 ac Runoff coeff. = 0.2 Intensity = 1.850 in/hr Tc by TR55 = 20.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 63 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 7&10-Pond 6 Hyd. No. 7 -- 10 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 8 Total Post-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.428 cfs Storm frequency = 10 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 1,105 cuft Drainage area = 0.490 ac Runoff coeff. = 0.84 Intensity = 1.041 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 8.6 x Tc Target Q =0.180 cfs Est. Req'd Storage =842 cuft 64 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Post-Development Basins 7&10-Pond 6 Hyd. No. 8 -- 10 Year Hyd No. 8 Mod. Rational Est. Storage = 842 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 9 Pond 3 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.000 cfs Storm frequency = 10 yrs Time to peak = n/a Time interval = 1 min Hyd. volume = 0 cuft Inflow hyd. No. = 2 - Post-Development Basin 3-Pond 3Max. Elevation = 4702.25 ft Reservoir name = POND 3 Max. Storage = 2,696 cuft Storage Indication method used. 65 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Pond 3 Routed Outflow Hyd. No. 9 -- 10 Year Hyd No. 9 Hyd No. 2 Total storage used = 2,696 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 10 Pond 5 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.125 cfs Storm frequency = 10 yrs Time to peak = 38 min Time interval = 1 min Hyd. volume = 99 cuft Inflow hyd. No. = 6 - Total Post-Development Basins 6&9-Pond 5Max. Elevation = 4701.26 ft Reservoir name = POND 5 Max. Storage = 693 cuft Storage Indication method used. 66 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Pond 5 Routed Outflow Hyd. No. 10 -- 10 Year Hyd No. 10 Hyd No. 6 Total storage used = 693 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 11 Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hydrograph type = Combine Peak discharge = 0.553 cfs Storm frequency = 10 yrs Time to peak = 38 min Time interval = 1 min Hyd. volume = 1,204 cuft Inflow hyds. = 8, 9, 10 Contrib. drain. area = 0.490 ac 67 0 10 20 30 40 50 60 70 80 90 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hyd. No. 11 -- 10 Year Hyd No. 11 Hyd No. 8 Hyd No. 9 Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 12 Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hydrograph type = Combine Peak discharge = 0.727 cfs Storm frequency = 10 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,185 cuft Inflow hyds. = 1, 5, 7 Contrib. drain. area = 2.550 ac 68 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hyd. No. 12 -- 10 Year Hyd No. 12 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 13 Pond 6 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.499 cfs Storm frequency = 10 yrs Time to peak = 41 min Time interval = 1 min Hyd. volume = 415 cuft Inflow hyd. No. = 11 - Total Pond 6 Routed Inflow (P3,P5,B7&B10)Max. Elevation = 4696.99 ft Reservoir name = POND 6 Max. Storage = 840 cuft Storage Indication method used. 69 0 10 20 30 40 50 60 70 80 90 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pond 6 Routed Outflow Hyd. No. 13 -- 10 Year Hyd No. 13 Hyd No. 11 Total storage used = 840 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 14 Pre-Development Basin 1-Pond 1 Hydrograph type = Mod. Rational Peak discharge = 0.047 cfs Storm frequency = 10 yrs Time to peak = 21 min Time interval = 1 min Hyd. volume = 59 cuft Drainage area = 0.130 ac Runoff coeff. = 0.2 Intensity = 1.789 in/hr Tc by TR55 = 21.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 70 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 1-Pond 1 Hyd. No. 14 -- 10 Year Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 15 Pre-Development Basin 2-Pond 2 Hydrograph type = Mod. Rational Peak discharge = 0.036 cfs Storm frequency = 10 yrs Time to peak = 15 min Time interval = 1 min Hyd. volume = 32 cuft Drainage area = 0.080 ac Runoff coeff. = 0.2 Intensity = 2.235 in/hr Tc by TR55 = 15.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 71 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 2-Pond 2 Hyd. No. 15 -- 10 Year Hyd No. 15 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 16 Pond 4 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.259 cfs Storm frequency = 10 yrs Time to peak = 49 min Time interval = 1 min Hyd. volume = 66 cuft Inflow hyd. No. = 4 - Tota Post-Development Basins 4,5&8-Pond 4Max. Elevation = 4700.06 ft Reservoir name = POND 4 Max. Storage = 2,078 cuft Storage Indication method used. 72 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Pond 4 Routed Outflow Hyd. No. 16 -- 10 Year Hyd No. 16 Hyd No. 4 Total storage used = 2,078 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 17 McIlhatten Basin 3 - Offsite Hydrograph type = Mod. Rational Peak discharge = 0.446 cfs Storm frequency = 10 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 134 cuft Drainage area = 0.180 ac Runoff coeff. = 0.64* Intensity = 3.869 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a * Composite (Area/C) = [(0.065 x 0.95) + (0.057 x 0.75) + (0.059 x 0.20)] / 0.180 73 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) McIlhatten Basin 3 - Offsite Hyd. No. 17 -- 10 Year Hyd No. 17 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 18 8-inch Culvert Drainage Hydrograph type = Mod. Rational Peak discharge = 0.112 cfs Storm frequency = 10 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 34 cuft Drainage area = 0.145 ac Runoff coeff. = 0.2 Intensity = 3.869 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 74 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) 8-inch Culvert Drainage Hyd. No. 18 -- 10 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 19 Total Pre-Development North Hydrograph type = Combine Peak discharge = 0.791 cfs Storm frequency = 10 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,237 cuft Inflow hyds. = 3, 14 Contrib. drain. area = 1.360 ac 75 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pre-Development North Hyd. No. 19 -- 10 Year Hyd No. 19 Hyd No. 3 Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 20 Total Pre-Development South Hydrograph type = Combine Peak discharge = 0.736 cfs Storm frequency = 10 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,218 cuft Inflow hyds. = 1, 5, 7, 15 Contrib. drain. area = 2.630 ac 76 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pre-Development South Hyd. No. 20 -- 10 Year Hyd No. 20 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hyd No. 15 Hydrograph Summary Report 77 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 Mod. Rational 0.636 1 26 992 ------ ------ ------ Pre-Development Basin 3-Pond 3 2 Mod. Rational 1.581 1 25 3,343 ------ ------ ------ Post-Development Basin 3-Pond 3 3 Mod. Rational 0.931 1 26 1,452 ------ ------ ------ Total Pre-Development Basins 4,5&8- 4 Mod. Rational 1.567 1 26 2,640 ------ ------ ------ Tota Post-Development Basins 4,5&8 5 Mod. Rational 0.186 1 18 201 ------ ------ ------ Total Pre-Development Basins 6&9-P 6 Mod. Rational 0.423 1 5 889 ------ ------ ------ Total Post-Development Basins 6&9- 7 Mod. Rational 0.223 1 20 268 ------ ------ ------ Total Pre-Development Basins 7&10- 8 Mod. Rational 0.527 1 5 1,360 ------ ------ ------ Total Post-Development Basins 7&10 9 Reservoir 0.164 1 57 297 2 4702.92 3,250 Pond 3 Routed Outflow 10 Reservoir 0.185 1 38 266 6 4701.95 791 Pond 5 Routed Outflow 11 Combine 0.712 1 38 1,922 8, 9, 10 ------ ------ Total Pond 6 Routed Inflow (P3,P5,B 12 Combine 0.896 1 26 1,461 1, 5, 7, ------ ------ Total Pond 6 Pre-Development Inflow 13 Reservoir 0.644 1 43 1,134 11 4697.54 914 Pond 6 Routed Outflow 14 Mod. Rational 0.057 1 21 72 ------ ------ ------ Pre-Development Basin 1-Pond 1 15 Mod. Rational 0.044 1 15 40 ------ ------ ------ Pre-Development Basin 2-Pond 2 16 Reservoir 0.699 1 42 562 4 4701.03 2,169 Pond 4 Routed Outflow 17 Mod. Rational 0.548 1 5 164 ------ ------ ------ McIlhatten Basin 3 - Offsite 18 Mod. Rational 0.138 1 5 41 ------ ------ ------ 8-inch Culvert Drainage 19 Combine 0.975 1 26 1,524 3, 14, ------ ------ Total Pre-Development North 20 Combine 0.907 1 20 1,501 1, 5, 7, 15, ------ ------ Total Pre-Development South 22147_Bikefill_Onsite_Hydraflow.gpw Return Period: 25 Year Tuesday, 08 / 18 / 2026 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 1 Pre-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 0.636 cfs Storm frequency = 25 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 992 cuft Drainage area = 1.680 ac Runoff coeff. = 0.2 Intensity = 1.892 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 78 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pre-Development Basin 3-Pond 3 Hyd. No. 1 -- 25 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 2 Post-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 1.581 cfs Storm frequency = 25 yrs Time to peak = 25 min Time interval = 1 min Hyd. volume = 3,343 cuft Drainage area = 1.680 ac Runoff coeff. = 0.627 Intensity = 1.501 in/hr Tc by TR55 = 25.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.4 x Tc Target Q =0.640 cfs Est. Req'd Storage =2,161 cuft 79 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Post-Development Basin 3-Pond 3 Hyd. No. 2 -- 25 Year Hyd No. 2 Mod. Rational Est. Storage = 2,161 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 3 Total Pre-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 0.931 cfs Storm frequency = 25 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,452 cuft Drainage area = 1.230 ac Runoff coeff. = 0.4 Intensity = 1.892 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 80 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pre-Development Basins 4,5&8-Pond 4 Hyd. No. 3 -- 25 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 4 Tota Post-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 1.567 cfs Storm frequency = 25 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 2,640 cuft Drainage area = 1.230 ac Runoff coeff. = 0.713 Intensity = 1.787 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.1 x Tc Target Q =0.930 cfs Est. Req'd Storage =1,125 cuft 81 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Tota Post-Development Basins 4,5&8-Pond 4 Hyd. No. 4 -- 25 Year Hyd No. 4 Mod. Rational Est. Storage = 1,125 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 5 Total Pre-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.186 cfs Storm frequency = 25 yrs Time to peak = 18 min Time interval = 1 min Hyd. volume = 201 cuft Drainage area = 0.380 ac Runoff coeff. = 0.2 Intensity = 2.449 in/hr Tc by TR55 = 18.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 82 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 6&9-Pond 5 Hyd. No. 5 -- 25 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 6 Total Post-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.423 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 889 cuft Drainage area = 0.380 ac Runoff coeff. = 0.738 Intensity = 1.509 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.0 x Tc Target Q =0.190 cfs Est. Req'd Storage =658 cuft 83 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Post-Development Basins 6&9-Pond 5 Hyd. No. 6 -- 25 Year Hyd No. 6 Mod. Rational Est. Storage = 658 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 7 Total Pre-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.223 cfs Storm frequency = 25 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 268 cuft Drainage area = 0.490 ac Runoff coeff. = 0.2 Intensity = 2.281 in/hr Tc by TR55 = 20.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 84 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 7&10-Pond 6 Hyd. No. 7 -- 25 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 8 Total Post-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.527 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 1,360 cuft Drainage area = 0.490 ac Runoff coeff. = 0.84 Intensity = 1.280 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 8.6 x Tc Target Q =0.220 cfs Est. Req'd Storage =1,038 cuft 85 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Post-Development Basins 7&10-Pond 6 Hyd. No. 8 -- 25 Year Hyd No. 8 Mod. Rational Est. Storage = 1,038 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 9 Pond 3 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.164 cfs Storm frequency = 25 yrs Time to peak = 57 min Time interval = 1 min Hyd. volume = 297 cuft Inflow hyd. No. = 2 - Post-Development Basin 3-Pond 3Max. Elevation = 4702.92 ft Reservoir name = POND 3 Max. Storage = 3,250 cuft Storage Indication method used. 86 0 30 60 90 120 150 180 210 240 270 300 330 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Pond 3 Routed Outflow Hyd. No. 9 -- 25 Year Hyd No. 9 Hyd No. 2 Total storage used = 3,250 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 10 Pond 5 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.185 cfs Storm frequency = 25 yrs Time to peak = 38 min Time interval = 1 min Hyd. volume = 266 cuft Inflow hyd. No. = 6 - Total Post-Development Basins 6&9-Pond 5Max. Elevation = 4701.95 ft Reservoir name = POND 5 Max. Storage = 791 cuft Storage Indication method used. 87 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Pond 5 Routed Outflow Hyd. No. 10 -- 25 Year Hyd No. 10 Hyd No. 6 Total storage used = 791 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 11 Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hydrograph type = Combine Peak discharge = 0.712 cfs Storm frequency = 25 yrs Time to peak = 38 min Time interval = 1 min Hyd. volume = 1,922 cuft Inflow hyds. = 8, 9, 10 Contrib. drain. area = 0.490 ac 88 0 20 40 60 80 100 120 140 160 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hyd. No. 11 -- 25 Year Hyd No. 11 Hyd No. 8 Hyd No. 9 Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 12 Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hydrograph type = Combine Peak discharge = 0.896 cfs Storm frequency = 25 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,461 cuft Inflow hyds. = 1, 5, 7 Contrib. drain. area = 2.550 ac 89 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hyd. No. 12 -- 25 Year Hyd No. 12 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 13 Pond 6 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.644 cfs Storm frequency = 25 yrs Time to peak = 43 min Time interval = 1 min Hyd. volume = 1,134 cuft Inflow hyd. No. = 11 - Total Pond 6 Routed Inflow (P3,P5,B7&B10)Max. Elevation = 4697.54 ft Reservoir name = POND 6 Max. Storage = 914 cuft Storage Indication method used. 90 0 20 40 60 80 100 120 140 160 180 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pond 6 Routed Outflow Hyd. No. 13 -- 25 Year Hyd No. 13 Hyd No. 11 Total storage used = 914 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 14 Pre-Development Basin 1-Pond 1 Hydrograph type = Mod. Rational Peak discharge = 0.057 cfs Storm frequency = 25 yrs Time to peak = 21 min Time interval = 1 min Hyd. volume = 72 cuft Drainage area = 0.130 ac Runoff coeff. = 0.2 Intensity = 2.205 in/hr Tc by TR55 = 21.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 91 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 1-Pond 1 Hyd. No. 14 -- 25 Year Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 15 Pre-Development Basin 2-Pond 2 Hydrograph type = Mod. Rational Peak discharge = 0.044 cfs Storm frequency = 25 yrs Time to peak = 15 min Time interval = 1 min Hyd. volume = 40 cuft Drainage area = 0.080 ac Runoff coeff. = 0.2 Intensity = 2.755 in/hr Tc by TR55 = 15.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 92 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 2-Pond 2 Hyd. No. 15 -- 25 Year Hyd No. 15 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 16 Pond 4 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.699 cfs Storm frequency = 25 yrs Time to peak = 42 min Time interval = 1 min Hyd. volume = 562 cuft Inflow hyd. No. = 4 - Tota Post-Development Basins 4,5&8-Pond 4Max. Elevation = 4701.03 ft Reservoir name = POND 4 Max. Storage = 2,169 cuft Storage Indication method used. 93 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Pond 4 Routed Outflow Hyd. No. 16 -- 25 Year Hyd No. 16 Hyd No. 4 Total storage used = 2,169 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 17 McIlhatten Basin 3 - Offsite Hydrograph type = Mod. Rational Peak discharge = 0.548 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 164 cuft Drainage area = 0.180 ac Runoff coeff. = 0.64* Intensity = 4.755 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a * Composite (Area/C) = [(0.065 x 0.95) + (0.057 x 0.75) + (0.059 x 0.20)] / 0.180 94 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) McIlhatten Basin 3 - Offsite Hyd. No. 17 -- 25 Year Hyd No. 17 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 18 8-inch Culvert Drainage Hydrograph type = Mod. Rational Peak discharge = 0.138 cfs Storm frequency = 25 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 41 cuft Drainage area = 0.145 ac Runoff coeff. = 0.2 Intensity = 4.755 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 95 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) 8-inch Culvert Drainage Hyd. No. 18 -- 25 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 19 Total Pre-Development North Hydrograph type = Combine Peak discharge = 0.975 cfs Storm frequency = 25 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,524 cuft Inflow hyds. = 3, 14 Contrib. drain. area = 1.360 ac 96 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pre-Development North Hyd. No. 19 -- 25 Year Hyd No. 19 Hyd No. 3 Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 20 Total Pre-Development South Hydrograph type = Combine Peak discharge = 0.907 cfs Storm frequency = 25 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 1,501 cuft Inflow hyds. = 1, 5, 7, 15 Contrib. drain. area = 2.630 ac 97 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pre-Development South Hyd. No. 20 -- 25 Year Hyd No. 20 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hyd No. 15 Hydrograph Summary Report 98 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 Mod. Rational 0.726 1 26 1,133 ------ ------ ------ Pre-Development Basin 3-Pond 3 2 Mod. Rational 1.802 1 25 3,811 ------ ------ ------ Post-Development Basin 3-Pond 3 3 Mod. Rational 1.063 1 26 1,659 ------ ------ ------ Total Pre-Development Basins 4,5&8- 4 Mod. Rational 1.789 1 26 3,014 ------ ------ ------ Tota Post-Development Basins 4,5&8 5 Mod. Rational 0.213 1 18 230 ------ ------ ------ Total Pre-Development Basins 6&9-P 6 Mod. Rational 0.482 1 5 1,013 ------ ------ ------ Total Post-Development Basins 6&9- 7 Mod. Rational 0.255 1 20 307 ------ ------ ------ Total Pre-Development Basins 7&10- 8 Mod. Rational 0.649 1 5 1,520 ------ ------ ------ Total Post-Development Basins 7&10 9 Reservoir 0.492 1 53 761 2 4703.12 3,472 Pond 3 Routed Outflow 10 Reservoir 0.206 1 38 390 6 4702.26 871 Pond 5 Routed Outflow 11 Combine 0.856 1 38 2,671 8, 9, 10 ------ ------ Total Pond 6 Routed Inflow (P3,P5,B 12 Combine 1.023 1 26 1,669 1, 5, 7, ------ ------ Total Pond 6 Pre-Development Inflow 13 Reservoir 0.724 1 40 1,882 11 4697.92 990 Pond 6 Routed Outflow 14 Mod. Rational 0.066 1 21 83 ------ ------ ------ Pre-Development Basin 1-Pond 1 15 Mod. Rational 0.050 1 15 45 ------ ------ ------ Pre-Development Basin 2-Pond 2 16 Reservoir 0.901 1 41 935 4 4701.51 2,270 Pond 4 Routed Outflow 17 Mod. Rational 0.624 1 5 187 ------ ------ ------ McIlhatten Basin 3 - Offsite 18 Mod. Rational 0.157 1 5 47 ------ ------ ------ 8-inch Culvert Drainage 19 Combine 1.113 1 26 1,741 3, 14, ------ ------ Total Pre-Development North 20 Combine 1.037 1 20 1,714 1, 5, 7, 15, ------ ------ Total Pre-Development South 22147_Bikefill_Onsite_Hydraflow.gpw Return Period: 50 Year Tuesday, 08 / 18 / 2026 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 1 Pre-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 0.726 cfs Storm frequency = 50 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,133 cuft Drainage area = 1.680 ac Runoff coeff. = 0.2 Intensity = 2.161 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 99 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pre-Development Basin 3-Pond 3 Hyd. No. 1 -- 50 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 2 Post-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 1.802 cfs Storm frequency = 50 yrs Time to peak = 25 min Time interval = 1 min Hyd. volume = 3,811 cuft Drainage area = 1.680 ac Runoff coeff. = 0.627 Intensity = 1.711 in/hr Tc by TR55 = 25.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.4 x Tc Target Q =0.730 cfs Est. Req'd Storage =2,463 cuft 100 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Post-Development Basin 3-Pond 3 Hyd. No. 2 -- 50 Year Hyd No. 2 Mod. Rational Est. Storage = 2,463 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 3 Total Pre-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 1.063 cfs Storm frequency = 50 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,659 cuft Drainage area = 1.230 ac Runoff coeff. = 0.4 Intensity = 2.161 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 101 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Total Pre-Development Basins 4,5&8-Pond 4 Hyd. No. 3 -- 50 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 4 Tota Post-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 1.789 cfs Storm frequency = 50 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 3,014 cuft Drainage area = 1.230 ac Runoff coeff. = 0.713 Intensity = 2.040 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.1 x Tc Target Q =1.060 cfs Est. Req'd Storage =1,286 cuft 102 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Tota Post-Development Basins 4,5&8-Pond 4 Hyd. No. 4 -- 50 Year Hyd No. 4 Mod. Rational Est. Storage = 1,286 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 5 Total Pre-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.213 cfs Storm frequency = 50 yrs Time to peak = 18 min Time interval = 1 min Hyd. volume = 230 cuft Drainage area = 0.380 ac Runoff coeff. = 0.2 Intensity = 2.800 in/hr Tc by TR55 = 18.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 103 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 6&9-Pond 5 Hyd. No. 5 -- 50 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 6 Total Post-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.482 cfs Storm frequency = 50 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 1,013 cuft Drainage area = 0.380 ac Runoff coeff. = 0.738 Intensity = 1.720 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.0 x Tc Target Q =0.210 cfs Est. Req'd Storage =758 cuft 104 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Post-Development Basins 6&9-Pond 5 Hyd. No. 6 -- 50 Year Hyd No. 6 Mod. Rational Est. Storage = 758 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 7 Total Pre-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.255 cfs Storm frequency = 50 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 307 cuft Drainage area = 0.490 ac Runoff coeff. = 0.2 Intensity = 2.607 in/hr Tc by TR55 = 20.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 105 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 7&10-Pond 6 Hyd. No. 7 -- 50 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 8 Total Post-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.649 cfs Storm frequency = 50 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 1,520 cuft Drainage area = 0.490 ac Runoff coeff. = 0.84 Intensity = 1.578 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.8 x Tc Target Q =0.250 cfs Est. Req'd Storage =1,183 cuft 106 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Post-Development Basins 7&10-Pond 6 Hyd. No. 8 -- 50 Year Hyd No. 8 Mod. Rational Est. Storage = 1,183 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 9 Pond 3 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.492 cfs Storm frequency = 50 yrs Time to peak = 53 min Time interval = 1 min Hyd. volume = 761 cuft Inflow hyd. No. = 2 - Post-Development Basin 3-Pond 3Max. Elevation = 4703.12 ft Reservoir name = POND 3 Max. Storage = 3,472 cuft Storage Indication method used. 107 0 20 40 60 80 100 120 140 160 180 200 220 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Pond 3 Routed Outflow Hyd. No. 9 -- 50 Year Hyd No. 9 Hyd No. 2 Total storage used = 3,472 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 10 Pond 5 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.206 cfs Storm frequency = 50 yrs Time to peak = 38 min Time interval = 1 min Hyd. volume = 390 cuft Inflow hyd. No. = 6 - Total Post-Development Basins 6&9-Pond 5Max. Elevation = 4702.26 ft Reservoir name = POND 5 Max. Storage = 871 cuft Storage Indication method used. 108 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Pond 5 Routed Outflow Hyd. No. 10 -- 50 Year Hyd No. 10 Hyd No. 6 Total storage used = 871 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 11 Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hydrograph type = Combine Peak discharge = 0.856 cfs Storm frequency = 50 yrs Time to peak = 38 min Time interval = 1 min Hyd. volume = 2,671 cuft Inflow hyds. = 8, 9, 10 Contrib. drain. area = 0.490 ac 109 0 20 40 60 80 100 120 140 160 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hyd. No. 11 -- 50 Year Hyd No. 11 Hyd No. 8 Hyd No. 9 Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 12 Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hydrograph type = Combine Peak discharge = 1.023 cfs Storm frequency = 50 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,669 cuft Inflow hyds. = 1, 5, 7 Contrib. drain. area = 2.550 ac 110 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hyd. No. 12 -- 50 Year Hyd No. 12 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 13 Pond 6 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.724 cfs Storm frequency = 50 yrs Time to peak = 40 min Time interval = 1 min Hyd. volume = 1,882 cuft Inflow hyd. No. = 11 - Total Pond 6 Routed Inflow (P3,P5,B7&B10)Max. Elevation = 4697.92 ft Reservoir name = POND 6 Max. Storage = 990 cuft Storage Indication method used. 111 0 20 40 60 80 100 120 140 160 180 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pond 6 Routed Outflow Hyd. No. 13 -- 50 Year Hyd No. 13 Hyd No. 11 Total storage used = 990 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 14 Pre-Development Basin 1-Pond 1 Hydrograph type = Mod. Rational Peak discharge = 0.066 cfs Storm frequency = 50 yrs Time to peak = 21 min Time interval = 1 min Hyd. volume = 83 cuft Drainage area = 0.130 ac Runoff coeff. = 0.2 Intensity = 2.520 in/hr Tc by TR55 = 21.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 112 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 1-Pond 1 Hyd. No. 14 -- 50 Year Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 15 Pre-Development Basin 2-Pond 2 Hydrograph type = Mod. Rational Peak discharge = 0.050 cfs Storm frequency = 50 yrs Time to peak = 15 min Time interval = 1 min Hyd. volume = 45 cuft Drainage area = 0.080 ac Runoff coeff. = 0.2 Intensity = 3.150 in/hr Tc by TR55 = 15.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 113 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 2-Pond 2 Hyd. No. 15 -- 50 Year Hyd No. 15 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 16 Pond 4 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.901 cfs Storm frequency = 50 yrs Time to peak = 41 min Time interval = 1 min Hyd. volume = 935 cuft Inflow hyd. No. = 4 - Tota Post-Development Basins 4,5&8-Pond 4Max. Elevation = 4701.51 ft Reservoir name = POND 4 Max. Storage = 2,270 cuft Storage Indication method used. 114 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Pond 4 Routed Outflow Hyd. No. 16 -- 50 Year Hyd No. 16 Hyd No. 4 Total storage used = 2,270 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 17 McIlhatten Basin 3 - Offsite Hydrograph type = Mod. Rational Peak discharge = 0.624 cfs Storm frequency = 50 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 187 cuft Drainage area = 0.180 ac Runoff coeff. = 0.64* Intensity = 5.416 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a * Composite (Area/C) = [(0.065 x 0.95) + (0.057 x 0.75) + (0.059 x 0.20)] / 0.180 115 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) McIlhatten Basin 3 - Offsite Hyd. No. 17 -- 50 Year Hyd No. 17 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 18 8-inch Culvert Drainage Hydrograph type = Mod. Rational Peak discharge = 0.157 cfs Storm frequency = 50 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 47 cuft Drainage area = 0.145 ac Runoff coeff. = 0.2 Intensity = 5.416 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 116 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) 8-inch Culvert Drainage Hyd. No. 18 -- 50 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 19 Total Pre-Development North Hydrograph type = Combine Peak discharge = 1.113 cfs Storm frequency = 50 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,741 cuft Inflow hyds. = 3, 14 Contrib. drain. area = 1.360 ac 117 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Total Pre-Development North Hyd. No. 19 -- 50 Year Hyd No. 19 Hyd No. 3 Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 20 Total Pre-Development South Hydrograph type = Combine Peak discharge = 1.037 cfs Storm frequency = 50 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 1,714 cuft Inflow hyds. = 1, 5, 7, 15 Contrib. drain. area = 2.630 ac 118 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Total Pre-Development South Hyd. No. 20 -- 50 Year Hyd No. 20 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hyd No. 15 Hydrograph Summary Report 119 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 Mod. Rational 0.816 1 26 1,272 ------ ------ ------ Pre-Development Basin 3-Pond 3 2 Mod. Rational 2.026 1 25 4,285 ------ ------ ------ Post-Development Basin 3-Pond 3 3 Mod. Rational 1.194 1 26 1,863 ------ ------ ------ Total Pre-Development Basins 4,5&8- 4 Mod. Rational 2.010 1 26 3,387 ------ ------ ------ Tota Post-Development Basins 4,5&8 5 Mod. Rational 0.239 1 18 258 ------ ------ ------ Total Pre-Development Basins 6&9-P 6 Mod. Rational 0.542 1 5 1,139 ------ ------ ------ Total Post-Development Basins 6&9- 7 Mod. Rational 0.287 1 20 344 ------ ------ ------ Total Pre-Development Basins 7&10- 8 Mod. Rational 0.730 1 5 1,709 ------ ------ ------ Total Post-Development Basins 7&10 9 Reservoir 0.808 1 50 1,232 2 4703.28 3,639 Pond 3 Routed Outflow 10 Reservoir 0.231 1 38 516 6 4702.49 955 Pond 5 Routed Outflow 11 Combine 1.047 1 39 3,458 8, 9, 10 ------ ------ Total Pond 6 Routed Inflow (P3,P5,B 12 Combine 1.149 1 26 1,874 1, 5, 7, ------ ------ Total Pond 6 Pre-Development Inflow 13 Reservoir 0.851 1 56 2,669 11 4698.55 1,188 Pond 6 Routed Outflow 14 Mod. Rational 0.074 1 21 93 ------ ------ ------ Pre-Development Basin 1-Pond 1 15 Mod. Rational 0.057 1 15 51 ------ ------ ------ Pre-Development Basin 2-Pond 2 16 Reservoir 1.032 1 41 1,306 4 4701.92 2,404 Pond 4 Routed Outflow 17 Mod. Rational 0.701 1 5 210 ------ ------ ------ McIlhatten Basin 3 - Offsite 18 Mod. Rational 0.176 1 5 53 ------ ------ ------ 8-inch Culvert Drainage 19 Combine 1.250 1 26 1,956 3, 14, ------ ------ Total Pre-Development North 20 Combine 1.164 1 20 1,925 1, 5, 7, 15, ------ ------ Total Pre-Development South 22147_Bikefill_Onsite_Hydraflow.gpw Return Period: 100 Year Tuesday, 08 / 18 / 2026 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 1 Pre-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 0.816 cfs Storm frequency = 100 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,272 cuft Drainage area = 1.680 ac Runoff coeff. = 0.2 Intensity = 2.427 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 120 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pre-Development Basin 3-Pond 3 Hyd. No. 1 -- 100 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 2 Post-Development Basin 3-Pond 3 Hydrograph type = Mod. Rational Peak discharge = 2.026 cfs Storm frequency = 100 yrs Time to peak = 25 min Time interval = 1 min Hyd. volume = 4,285 cuft Drainage area = 1.680 ac Runoff coeff. = 0.627 Intensity = 1.923 in/hr Tc by TR55 = 25.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.4 x Tc Target Q =0.820 cfs Est. Req'd Storage =2,770 cuft 121 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 Q (cfs) Time (min) Post-Development Basin 3-Pond 3 Hyd. No. 2 -- 100 Year Hyd No. 2 Mod. Rational Est. Storage = 2,770 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 3 Total Pre-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 1.194 cfs Storm frequency = 100 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,863 cuft Drainage area = 1.230 ac Runoff coeff. = 0.4 Intensity = 2.427 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 122 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Total Pre-Development Basins 4,5&8-Pond 4 Hyd. No. 3 -- 100 Year Hyd No. 3 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 4 Tota Post-Development Basins 4,5&8-Pond 4 Hydrograph type = Mod. Rational Peak discharge = 2.010 cfs Storm frequency = 100 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 3,387 cuft Drainage area = 1.230 ac Runoff coeff. = 0.713 Intensity = 2.292 in/hr Tc by TR55 = 26.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.1 x Tc Target Q =1.190 cfs Est. Req'd Storage =1,446 cuft 123 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 Q (cfs) Time (min) Tota Post-Development Basins 4,5&8-Pond 4 Hyd. No. 4 -- 100 Year Hyd No. 4 Mod. Rational Est. Storage = 1,446 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 5 Total Pre-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.239 cfs Storm frequency = 100 yrs Time to peak = 18 min Time interval = 1 min Hyd. volume = 258 cuft Drainage area = 0.380 ac Runoff coeff. = 0.2 Intensity = 3.143 in/hr Tc by TR55 = 18.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 124 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 6&9-Pond 5 Hyd. No. 5 -- 100 Year Hyd No. 5 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 6 Total Post-Development Basins 6&9-Pond 5 Hydrograph type = Mod. Rational Peak discharge = 0.542 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 1,139 cuft Drainage area = 0.380 ac Runoff coeff. = 0.738 Intensity = 1.934 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.0 x Tc Target Q =0.240 cfs Est. Req'd Storage =847 cuft 125 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Post-Development Basins 6&9-Pond 5 Hyd. No. 6 -- 100 Year Hyd No. 6 Mod. Rational Est. Storage = 847 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 7 Total Pre-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.287 cfs Storm frequency = 100 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 344 cuft Drainage area = 0.490 ac Runoff coeff. = 0.2 Intensity = 2.927 in/hr Tc by TR55 = 20.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 126 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) Total Pre-Development Basins 7&10-Pond 6 Hyd. No. 7 -- 100 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 8 Total Post-Development Basins 7&10-Pond 6 Hydrograph type = Mod. Rational Peak discharge = 0.730 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 1,709 cuft Drainage area = 0.490 ac Runoff coeff. = 0.84 Intensity = 1.775 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 7.8 x Tc Target Q =0.290 cfs Est. Req'd Storage =1,319 cuft 127 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Total Post-Development Basins 7&10-Pond 6 Hyd. No. 8 -- 100 Year Hyd No. 8 Mod. Rational Est. Storage = 1,319 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 9 Pond 3 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.808 cfs Storm frequency = 100 yrs Time to peak = 50 min Time interval = 1 min Hyd. volume = 1,232 cuft Inflow hyd. No. = 2 - Post-Development Basin 3-Pond 3Max. Elevation = 4703.28 ft Reservoir name = POND 3 Max. Storage = 3,639 cuft Storage Indication method used. 128 0 20 40 60 80 100 120 140 160 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 Q (cfs) Time (min) Pond 3 Routed Outflow Hyd. No. 9 -- 100 Year Hyd No. 9 Hyd No. 2 Total storage used = 3,639 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 10 Pond 5 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.231 cfs Storm frequency = 100 yrs Time to peak = 38 min Time interval = 1 min Hyd. volume = 516 cuft Inflow hyd. No. = 6 - Total Post-Development Basins 6&9-Pond 5Max. Elevation = 4702.49 ft Reservoir name = POND 5 Max. Storage = 955 cuft Storage Indication method used. 129 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) Pond 5 Routed Outflow Hyd. No. 10 -- 100 Year Hyd No. 10 Hyd No. 6 Total storage used = 955 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 11 Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hydrograph type = Combine Peak discharge = 1.047 cfs Storm frequency = 100 yrs Time to peak = 39 min Time interval = 1 min Hyd. volume = 3,458 cuft Inflow hyds. = 8, 9, 10 Contrib. drain. area = 0.490 ac 130 0 20 40 60 80 100 120 140 160 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Total Pond 6 Routed Inflow (P3,P5,B7&B10) Hyd. No. 11 -- 100 Year Hyd No. 11 Hyd No. 8 Hyd No. 9 Hyd No. 10 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 12 Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hydrograph type = Combine Peak discharge = 1.149 cfs Storm frequency = 100 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,874 cuft Inflow hyds. = 1, 5, 7 Contrib. drain. area = 2.550 ac 131 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Total Pond 6 Pre-Development Inflow (B3,6,7,9,10) Hyd. No. 12 -- 100 Year Hyd No. 12 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 13 Pond 6 Routed Outflow Hydrograph type = Reservoir Peak discharge = 0.851 cfs Storm frequency = 100 yrs Time to peak = 56 min Time interval = 1 min Hyd. volume = 2,669 cuft Inflow hyd. No. = 11 - Total Pond 6 Routed Inflow (P3,P5,B7&B10)Max. Elevation = 4698.55 ft Reservoir name = POND 6 Max. Storage = 1,188 cuft Storage Indication method used. 132 0 20 40 60 80 100 120 140 160 180 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Pond 6 Routed Outflow Hyd. No. 13 -- 100 Year Hyd No. 13 Hyd No. 11 Total storage used = 1,188 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 14 Pre-Development Basin 1-Pond 1 Hydrograph type = Mod. Rational Peak discharge = 0.074 cfs Storm frequency = 100 yrs Time to peak = 21 min Time interval = 1 min Hyd. volume = 93 cuft Drainage area = 0.130 ac Runoff coeff. = 0.2 Intensity = 2.829 in/hr Tc by TR55 = 21.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 133 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 1-Pond 1 Hyd. No. 14 -- 100 Year Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 15 Pre-Development Basin 2-Pond 2 Hydrograph type = Mod. Rational Peak discharge = 0.057 cfs Storm frequency = 100 yrs Time to peak = 15 min Time interval = 1 min Hyd. volume = 51 cuft Drainage area = 0.080 ac Runoff coeff. = 0.2 Intensity = 3.535 in/hr Tc by TR55 = 15.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 134 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) Pre-Development Basin 2-Pond 2 Hyd. No. 15 -- 100 Year Hyd No. 15 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 16 Pond 4 Routed Outflow Hydrograph type = Reservoir Peak discharge = 1.032 cfs Storm frequency = 100 yrs Time to peak = 41 min Time interval = 1 min Hyd. volume = 1,306 cuft Inflow hyd. No. = 4 - Tota Post-Development Basins 4,5&8-Pond 4Max. Elevation = 4701.92 ft Reservoir name = POND 4 Max. Storage = 2,404 cuft Storage Indication method used. 135 0 10 20 30 40 50 60 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 Q (cfs) Time (min) Pond 4 Routed Outflow Hyd. No. 16 -- 100 Year Hyd No. 16 Hyd No. 4 Total storage used = 2,404 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 17 McIlhatten Basin 3 - Offsite Hydrograph type = Mod. Rational Peak discharge = 0.701 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 210 cuft Drainage area = 0.180 ac Runoff coeff. = 0.64* Intensity = 6.083 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a * Composite (Area/C) = [(0.065 x 0.95) + (0.057 x 0.75) + (0.059 x 0.20)] / 0.180 136 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) McIlhatten Basin 3 - Offsite Hyd. No. 17 -- 100 Year Hyd No. 17 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 18 8-inch Culvert Drainage Hydrograph type = Mod. Rational Peak discharge = 0.176 cfs Storm frequency = 100 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 53 cuft Drainage area = 0.145 ac Runoff coeff. = 0.2 Intensity = 6.083 in/hr Tc by User = 5.00 min IDF Curve = IDF_BOZEMAN_Rational.IDF Storm duration = 1.0 x Tc Target Q =n/a Est. Req'd Storage =n/a 137 0 1 2 3 4 5 6 7 8 9 10 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) 8-inch Culvert Drainage Hyd. No. 18 -- 100 Year Hyd No. 18 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 19 Total Pre-Development North Hydrograph type = Combine Peak discharge = 1.250 cfs Storm frequency = 100 yrs Time to peak = 26 min Time interval = 1 min Hyd. volume = 1,956 cuft Inflow hyds. = 3, 14 Contrib. drain. area = 1.360 ac 138 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Total Pre-Development North Hyd. No. 19 -- 100 Year Hyd No. 19 Hyd No. 3 Hyd No. 14 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Hyd. No. 20 Total Pre-Development South Hydrograph type = Combine Peak discharge = 1.164 cfs Storm frequency = 100 yrs Time to peak = 20 min Time interval = 1 min Hyd. volume = 1,925 cuft Inflow hyds. = 1, 5, 7, 15 Contrib. drain. area = 2.630 ac 139 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) Total Pre-Development South Hyd. No. 20 -- 100 Year Hyd No. 20 Hyd No. 1 Hyd No. 5 Hyd No. 7 Hyd No. 15 Hydraflow Rainfall Report 140 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2026 Tuesday, 08 / 18 / 2026 Return Intensity-Duration-Frequency Equation Coefficients (FHA) Period (Yrs) B D E (N/A) 1 0.0000 0.0000 0.0000 -------- 2 33.9356 9.9000 1.0341 -------- 3 0.0000 0.0000 0.0000 -------- 5 42.6620 8.8000 0.9925 -------- 10 44.6763 7.9000 0.9566 -------- 25 57.8038 8.2000 0.9680 -------- 50 72.0182 8.7000 0.9886 -------- 100 77.8038 8.5000 0.9792 -------- File name: IDF_BOZEMAN_Rational.IDF Intensity = B / (Tc + D)^E Return Intensity Values (in/hr) Period (Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2 2.08 1.54 1.22 1.01 0.86 0.75 0.66 0.60 0.54 0.49 0.45 0.42 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 3.15 2.32 1.84 1.52 1.30 1.13 1.00 0.90 0.82 0.75 0.69 0.64 10 3.87 2.83 2.23 1.85 1.58 1.38 1.23 1.10 1.00 0.92 0.85 0.79 25 4.76 3.48 2.75 2.28 1.95 1.70 1.51 1.36 1.23 1.13 1.04 0.97 50 5.42 3.98 3.15 2.61 2.22 1.94 1.72 1.55 1.40 1.29 1.19 1.10 100 6.08 4.47 3.54 2.93 2.50 2.18 1.93 1.74 1.58 1.45 1.34 1.24 Tc = time in minutes. Values may exceed 60. Rainfall Precipitation Table (in) Precip. file name: Sample.pcp Storm Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCS 24-hour 0.00 1.18 0.00 1.49 1.70 1.96 2.15 2.34 SCS 6-Hr 0.00 0.71 0.00 0.88 0.99 1.14 1.24 1.35 Huff-1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Custom 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 City of Bozeman Intensity-Duration-Frequency Coefficients modified with City of Bozeman Frequency Factors. APPENDIX C HYDRAULIC CALCULATIONS BIKEFILL BIKE PARK 22147.01 Hydraulic Analysis Report Project Data Project Title: 22147.01 Bikefill Bike Park Onsite Design Designer: Bobby Egeberg Project Date: Thursday, April 30, 2026 Project Units: U.S. Customary Units Notes: Channel Analysis: North Drainage Ditch Notes: North drainage swale east of proposed pump track. See sheet C5.2. Input Parameters Channel Type: Trapezoidal Side Slope 1 (Z1): 3.0000 ft/ft Side Slope 2 (Z2): 3.0000 ft/ft Channel Width 5.00 ft Longitudinal Slope: 0.0050 ft/ft Manning's n: 0.0250 Flow 94.7000 cfs Result Parameters Depth 1.8856 ft Area of Flow 20.0941 ft^2 Wetted Perimeter 16.9255 ft Hydraulic Radius 1.1872 ft Average Velocity 4.7128 ft/s Top Width 16.3135 ft Froude Number: 0.7483 Critical Depth 1.6225 ft Critical Velocity 5.9149 ft/s Critical Slope: 0.0093 ft/ft Critical Top Width 14.74 ft Calculated Max Shear Stress 0.5883 lb/ft^2 Calculated Avg Shear Stress 0.3704 lb/ft^2 Hydraulic Analysis Report Project Data Project Title: 22147 Bikefill Bike Park Onsite Designer: Lura Johnson Project Date: Friday, August 7, 2026 Project Units: U.S. Customary Units Notes: Channel Analysis: 12" Pond 4 Out 100-yr Notes: Input Parameters Channel Type: Circular Pipe Diameter 1.00 ft Longitudinal Slope: 0.0134 ft/ft Manning's n: 0.0130 Flow 1.0320 cfs Result Parameters Depth 0.3409 ft Area of Flow 0.2364 ft^2 Wetted Perimeter 1.2471 ft Hydraulic Radius 0.1895 ft Average Velocity 4.3661 ft/s Top Width 0.9481 ft Froude Number: 1.5410 Critical Depth 0.4268 ft Critical Velocity 3.2278 ft/s Critical Slope: 0.0058 ft/ft Critical Top Width 0.99 ft Calculated Max Shear Stress 0.2851 lb/ft^2 Calculated Avg Shear Stress 0.1585 lb/ft^2 Channel Analysis: 12" Pond 4 Out 10-yr Notes: Input Parameters Channel Type: Circular Pipe Diameter 1.00 ft Longitudinal Slope: 0.0134 ft/ft Manning's n: 0.0130 Flow 0.2590 cfs Result Parameters Depth 0.1699 ft Area of Flow 0.0885 ft^2 Wetted Perimeter 0.8497 ft Hydraulic Radius 0.1041 ft Average Velocity 2.9281 ft/s Top Width 0.7511 ft Froude Number: 1.5037 Critical Depth 0.2092 ft Critical Velocity 2.1716 ft/s Critical Slope: 0.0057 ft/ft Critical Top Width 0.81 ft Calculated Max Shear Stress 0.1421 lb/ft^2 Calculated Avg Shear Stress 0.0870 lb/ft^2 Channel Analysis: 8" Pond 5 Out 100-yr Notes: Input Parameters Channel Type: Circular Pipe Diameter 0.67 ft Longitudinal Slope: 0.0100 ft/ft Manning's n: 0.0150 Flow 0.2310 cfs Result Parameters Depth 0.2123 ft Area of Flow 0.0960 ft^2 Wetted Perimeter 0.8012 ft Hydraulic Radius 0.1198 ft Average Velocity 2.4071 ft/s Top Width 0.6235 ft Froude Number: 1.0812 Critical Depth 0.2212 ft Critical Velocity 2.2759 ft/s Critical Slope: 0.0086 ft/ft Critical Top Width 0.63 ft Calculated Max Shear Stress 0.1325 lb/ft^2 Calculated Avg Shear Stress 0.0747 lb/ft^2 Channel Analysis: 8" Pond 5 Out 10-yr Notes: Input Parameters Channel Type: Circular Pipe Diameter 0.67 ft Longitudinal Slope: 0.0100 ft/ft Manning's n: 0.0150 Flow 0.1250 cfs Result Parameters Depth 0.1553 ft Area of Flow 0.0619 ft^2 Wetted Perimeter 0.6730 ft Hydraulic Radius 0.0920 ft Average Velocity 2.0190 ft/s Top Width 0.5654 ft Froude Number: 1.0752 Critical Depth 0.1611 ft Critical Velocity 1.9157 ft/s Critical Slope: 0.0086 ft/ft Critical Top Width 0.57 ft Calculated Max Shear Stress 0.0969 lb/ft^2 Calculated Avg Shear Stress 0.0574 lb/ft^2 Channel Analysis: 12" Pond 6 Out 100-yr Notes: Input Parameters Channel Type: Circular Pipe Diameter 1.00 ft Longitudinal Slope: 0.0200 ft/ft Manning's n: 0.0130 Flow 0.8510 cfs Result Parameters Depth 0.2780 ft Area of Flow 0.1783 ft^2 Wetted Perimeter 1.1108 ft Hydraulic Radius 0.1605 ft Average Velocity 4.7739 ft/s Top Width 0.8961 ft Froude Number: 1.8862 Critical Depth 0.3862 ft Critical Velocity 3.0402 ft/s Critical Slope: 0.0057 ft/ft Critical Top Width 0.97 ft Calculated Max Shear Stress 0.3470 lb/ft^2 Calculated Avg Shear Stress 0.2003 lb/ft^2 Channel Analysis: 12" Pond 6 Out 10-yr Notes: Input Parameters Channel Type: Circular Pipe Diameter 1.00 ft Longitudinal Slope: 0.0200 ft/ft Manning's n: 0.0130 Flow 0.4990 cfs Result Parameters Depth 0.2126 ft Area of Flow 0.1220 ft^2 Wetted Perimeter 0.9583 ft Hydraulic Radius 0.1273 ft Average Velocity 4.0908 ft/s Top Width 0.8182 ft Froude Number: 1.8671 Critical Depth 0.2930 ft Critical Velocity 2.6024 ft/s Critical Slope: 0.0056 ft/ft Critical Top Width 0.91 ft Calculated Max Shear Stress 0.2653 lb/ft^2 Calculated Avg Shear Stress 0.1589 lb/ft^2 Channel Analysis: 8" 100-YR Notes: Input Parameters Channel Type: Circular Pipe Diameter 0.67 ft Longitudinal Slope: 0.0505 ft/ft Manning's n: 0.0150 Flow 0.1760 cfs Result Parameters Depth 0.1232 ft Area of Flow 0.0445 ft^2 Wetted Perimeter 0.5938 ft Hydraulic Radius 0.0749 ft Average Velocity 3.9565 ft/s Top Width 0.5191 ft Froude Number: 2.3817 Critical Depth 0.1920 ft Critical Velocity 2.1081 ft/s Critical Slope: 0.0086 ft/ft Critical Top Width 0.61 ft Calculated Max Shear Stress 0.3881 lb/ft^2 Calculated Avg Shear Stress 0.2361 lb/ft^2 Channel Analysis: 8" 10-YR Notes: Input Parameters Channel Type: Circular Pipe Diameter 0.67 ft Longitudinal Slope: 0.0505 ft/ft Manning's n: 0.0150 Flow 0.1120 cfs Result Parameters Depth 0.0988 ft Area of Flow 0.0324 ft^2 Wetted Perimeter 0.5282 ft Hydraulic Radius 0.0613 ft Average Velocity 3.4600 ft/s Top Width 0.4752 ft Froude Number: 2.3362 Critical Depth 0.1523 ft Critical Velocity 1.8593 ft/s Critical Slope: 0.0087 ft/ft Critical Top Width 0.56 ft Calculated Max Shear Stress 0.3115 lb/ft^2 Calculated Avg Shear Stress 0.1931 lb/ft^2 Channel Analysis: 15" Culvert 10-YR Notes: Input Parameters Channel Type: Circular Pipe Diameter 1.25 ft Longitudinal Slope: 0.0380 ft/ft Manning's n: 0.0130 Flow 0.4460 cfs Result Parameters Depth 0.1610 ft Area of Flow 0.0924 ft^2 Wetted Perimeter 0.9175 ft Hydraulic Radius 0.1008 ft Average Velocity 4.8243 ft/s Top Width 0.8373 ft Froude Number: 2.5586 Critical Depth 0.2596 ft Critical Velocity 2.4194 ft/s Critical Slope: 0.0053 ft/ft Critical Top Width 1.01 ft Calculated Max Shear Stress 0.3816 lb/ft^2 Calculated Avg Shear Stress 0.2389 lb/ft^2 Channel Analysis: 15" Culvert 100-YR Notes: Input Parameters Channel Type: Circular Pipe Diameter 1.25 ft Longitudinal Slope: 0.0380 ft/ft Manning's n: 0.0130 Flow 0.7010 cfs Result Parameters Depth 0.2003 ft Area of Flow 0.1270 ft^2 Wetted Perimeter 1.0295 ft Hydraulic Radius 0.1233 ft Average Velocity 5.5207 ft/s Top Width 0.9170 ft Froude Number: 2.6145 Critical Depth 0.3271 ft Critical Velocity 2.7394 ft/s Critical Slope: 0.0052 ft/ft Critical Top Width 1.10 ft Calculated Max Shear Stress 0.4749 lb/ft^2 Calculated Avg Shear Stress 0.2925 lb/ft^2 Channel Analysis: Curb Opening Notes: Input Parameters Channel Type: Trapezoidal Side Slope 1 (Z1): 2.0000 ft/ft Side Slope 2 (Z2): 2.0000 ft/ft Channel Width 1.50 ft Longitudinal Slope: 0.0600 ft/ft Manning's n: 0.0150 Depth 0.5000 ft Result Parameters Flow 14.6187 cfs Area of Flow 1.2500 ft^2 Wetted Perimeter 3.7361 ft Hydraulic Radius 0.3346 ft Average Velocity 11.6950 ft/s Top Width 3.5000 ft Froude Number: 3.4487 Critical Depth 0.9604 ft Critical Velocity 4.4500 ft/s Critical Slope: 0.0043 ft/ft Critical Top Width 5.34 ft Calculated Max Shear Stress 1.8720 lb/ft^2 Calculated Avg Shear Stress 1.2527 lb/ft^2 Channel Analysis: 0.6' Pond 3 Curb Out Notes: Input Parameters Channel Type: Rectangular Channel Width 0.50 ft Longitudinal Slope: 0.0135 ft/ft Manning's n: 0.0150 Flow 0.8080 cfs Result Parameters Depth 0.4701 ft Area of Flow 0.2351 ft^2 Wetted Perimeter 1.4402 ft Hydraulic Radius 0.1632 ft Average Velocity 3.4375 ft/s Top Width 0.5000 ft Froude Number: 0.8835 Critical Depth 0.4329 ft Critical Velocity 3.7334 ft/s Critical Slope: 0.0166 ft/ft Critical Top Width 0.50 ft Calculated Max Shear Stress 0.3960 lb/ft^2 Calculated Avg Shear Stress 0.1375 lb/ft^2 APPENDIX D GROUNDWATER MOUNDIING CALCULATIONS BIKEFILL BIKE PARK 22147.01 POND 1 GROUNDWATER MOUNDING CALCULATIONS use consistent units (e.g. feet & days or inches & hours)Conversion Table Input Values inch/hour feet/day 1.0000 R Recharge (infiltration) rate (feet/day)0.67 1.33 0.150 Sy Specific yield, Sy (dimensionless, between 0 and 1) 10.00 K Horizontal hydraulic conductivity, Kh (feet/day)*2.00 4.00 5.000 x 1/2 length of basin (x direction, in feet) 20.000 y 1/2 width of basin (y direction, in feet)hours days 3.000 t duration of infiltration period (days)36 1.50 135.000 hi(0)initial thickness of saturated zone (feet) 135.157 h(max)maximum thickness of saturated zone (beneath center of basin at end of infiltration period) 0.157 Δh(max)maximum groundwater mounding (beneath center of basin at end of infiltration period) Ground- water Mounding, in feet Distance from center of basin in x direction, in feet 0.157 0 0.119 20 0.091 40 0.081 50 0.073 60 0.066 70 0.061 80 0.056 90 0.051 100 0.043 120 Disclaimer This spreadsheet solving the Hantush (1967) equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater infiltration basins" or to calculate values based on user-specified site conditions. Any changes made to the spreadsheet (other than values identified as user-specified) after transmission from the USGS could have unintended, undesirable consequences. These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report. The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet. If changes are made to the spreadsheet, the user is responsible for documenting the changes and justifying the results and conclusions. This spreadsheet will calculate the height of a groundwater mound beneath a stormwater infiltration basin. More information can be found in the U.S. Geological Survey Scientific Investigations Report 2010-5102 "Simulation of groundwater mounding beneath hypothetical stormwater infiltration basins". The user must specify infiltration rate (R), specific yield (Sy), horizontal hydraulic conductivity (Kh), basin dimensions (x, y), duration of infiltration period (t), and the initial thickness of the saturated zone (hi(0), height of the water table if the bottom of the aquifer is the datum). For a square basin the half width equals the half length (x = y). For a rectangular basin, if the user wants the water-table changes perpendicular to the long side, specify x as the short dimension and y as the long dimension. Conversely, if the user wants the values perpendicular to the short side, specify y as the short dimension, x as the long dimension. All distances are from the center of the basin. Users can change the distances from the center of the basin at which water-table aquifer thickness are calculated. Cells highlighted in yellow are values that can be changed by the user. Cells highlighted in red are output values based on user-specified inputs. The user MUST click the blue "Re-Calculate Now" button each time ANY of the user-specified inputs are changed otherwise necessary iterations to converge on the correct solution will not be done and values shown will be incorrect. Use consistent units for all input values (for example, feet and days) In the report accompanying this spreadsheet (USGS SIR 2010-5102), vertical soil permeability (ft/d) is assumed to be one-tenth horizontal hydraulic conductivity (ft/d). Re-Calculate Now 0.000 0.020 0.040 0.060 0.080 0.100 0.120 0.140 0.160 0.180 0 20 40 60 80 100 120 140 Groundwater Mounding, in feet 07/17/2026 LMJ/RPE POND 2 GROUNDWATER MOUNDING CALCULATIONS use consistent units (e.g. feet & days or inches & hours)Conversion Table Input Values inch/hour feet/day 1.0000 R Recharge (infiltration) rate (feet/day)0.67 1.33 0.150 Sy Specific yield, Sy (dimensionless, between 0 and 1) 10.00 K Horizontal hydraulic conductivity, Kh (feet/day)*2.00 4.00 5.000 x 1/2 length of basin (x direction, in feet) 10.000 y 1/2 width of basin (y direction, in feet)hours days 3.000 t duration of infiltration period (days)36 1.50 135.000 hi(0)initial thickness of saturated zone (feet) 135.091 h(max)maximum thickness of saturated zone (beneath center of basin at end of infiltration period) 0.091 Δh(max)maximum groundwater mounding (beneath center of basin at end of infiltration period) Ground- water Mounding, in feet Distance from center of basin in x direction, in feet 0.091 0 0.065 20 0.050 40 0.044 50 0.040 60 0.037 70 0.034 80 0.031 90 0.029 100 0.025 120 Disclaimer This spreadsheet solving the Hantush (1967) equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater infiltration basins" or to calculate values based on user-specified site conditions. Any changes made to the spreadsheet (other than values identified as user-specified) after transmission from the USGS could have unintended, undesirable consequences. These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report. The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet. If changes are made to the spreadsheet, the user is responsible for documenting the changes and justifying the results and conclusions. This spreadsheet will calculate the height of a groundwater mound beneath a stormwater infiltration basin. More information can be found in the U.S. Geological Survey Scientific Investigations Report 2010-5102 "Simulation of groundwater mounding beneath hypothetical stormwater infiltration basins". The user must specify infiltration rate (R), specific yield (Sy), horizontal hydraulic conductivity (Kh), basin dimensions (x, y), duration of infiltration period (t), and the initial thickness of the saturated zone (hi(0), height of the water table if the bottom of the aquifer is the datum). For a square basin the half width equals the half length (x = y). For a rectangular basin, if the user wants the water-table changes perpendicular to the long side, specify x as the short dimension and y as the long dimension. Conversely, if the user wants the values perpendicular to the short side, specify y as the short dimension, x as the long dimension. All distances are from the center of the basin. Users can change the distances from the center of the basin at which water-table aquifer thickness are calculated. Cells highlighted in yellow are values that can be changed by the user. Cells highlighted in red are output values based on user-specified inputs. The user MUST click the blue "Re-Calculate Now" button each time ANY of the user-specified inputs are changed otherwise necessary iterations to converge on the correct solution will not be done and values shown will be incorrect. Use consistent units for all input values (for example, feet and days) In the report accompanying this spreadsheet (USGS SIR 2010-5102), vertical soil permeability (ft/d) is assumed to be one-tenth horizontal hydraulic conductivity (ft/d). Re-Calculate Now 0.000 0.010 0.020 0.030 0.040 0.050 0.060 0.070 0.080 0.090 0.100 0 20 40 60 80 100 120 140 Groundwater Mounding, in feet 07/17/2026 LMJ/RPE POND 3 GROUNDWATER MOUNDING CALCULATIONS use consistent units (e.g. feet & days or inches & hours)Conversion Table Input Values inch/hour feet/day 1.0000 R Recharge (infiltration) rate (feet/day)0.67 1.33 0.150 Sy Specific yield, Sy (dimensionless, between 0 and 1) 10.00 K Horizontal hydraulic conductivity, Kh (feet/day)*2.00 4.00 9.875 x 1/2 length of basin (x direction, in feet) 18.466 y 1/2 width of basin (y direction, in feet)hours days 3.000 t duration of infiltration period (days)36 1.50 135.000 hi(0)initial thickness of saturated zone (feet) 135.276 h(max)maximum thickness of saturated zone (beneath center of basin at end of infiltration period) 0.276 Δh(max)maximum groundwater mounding (beneath center of basin at end of infiltration period) Ground- water Mounding, in feet Distance from center of basin in x direction, in feet 0.276 0 0.215 20 0.161 40 0.143 50 0.129 60 0.116 70 0.105 80 0.096 90 0.088 100 0.074 120 Disclaimer This spreadsheet solving the Hantush (1967) equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater infiltration basins" or to calculate values based on user-specified site conditions. Any changes made to the spreadsheet (other than values identified as user-specified) after transmission from the USGS could have unintended, undesirable consequences. These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report. The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet. If changes are made to the spreadsheet, the user is responsible for documenting the changes and justifying the results and conclusions. This spreadsheet will calculate the height of a groundwater mound beneath a stormwater infiltration basin. More information can be found in the U.S. Geological Survey Scientific Investigations Report 2010-5102 "Simulation of groundwater mounding beneath hypothetical stormwater infiltration basins". The user must specify infiltration rate (R), specific yield (Sy), horizontal hydraulic conductivity (Kh), basin dimensions (x, y), duration of infiltration period (t), and the initial thickness of the saturated zone (hi(0), height of the water table if the bottom of the aquifer is the datum). For a square basin the half width equals the half length (x = y). For a rectangular basin, if the user wants the water-table changes perpendicular to the long side, specify x as the short dimension and y as the long dimension. Conversely, if the user wants the values perpendicular to the short side, specify y as the short dimension, x as the long dimension. All distances are from the center of the basin. Users can change the distances from the center of the basin at which water-table aquifer thickness are calculated. Cells highlighted in yellow are values that can be changed by the user. Cells highlighted in red are output values based on user-specified inputs. The user MUST click the blue "Re-Calculate Now" button each time ANY of the user-specified inputs are changed otherwise necessary iterations to converge on the correct solution will not be done and values shown will be incorrect. Use consistent units for all input values (for example, feet and days) In the report accompanying this spreadsheet (USGS SIR 2010-5102), vertical soil permeability (ft/d) is assumed to be one-tenth horizontal hydraulic conductivity (ft/d). Re-Calculate Now 0.000 0.050 0.100 0.150 0.200 0.250 0.300 0 20 40 60 80 100 120 140 Groundwater Mounding, in feet 07/17/2026 LMJ/RPE POND 4 GROUNDWATER MOUNDING CALCULATIONS use consistent units (e.g. feet & days or inches & hours)Conversion Table Input Values inch/hour feet/day 1.0000 R Recharge (infiltration) rate (feet/day)0.67 1.33 0.150 Sy Specific yield, Sy (dimensionless, between 0 and 1) 10.00 K Horizontal hydraulic conductivity, Kh (feet/day)*2.00 4.00 9.875 x 1/2 length of basin (x direction, in feet) 21.630 y 1/2 width of basin (y direction, in feet)hours days 3.000 t duration of infiltration period (days)36 1.50 135.000 hi(0)initial thickness of saturated zone (feet) 135.313 h(max)maximum thickness of saturated zone (beneath center of basin at end of infiltration period) 0.313 Δh(max)maximum groundwater mounding (beneath center of basin at end of infiltration period) Ground- water Mounding, in feet Distance from center of basin in x direction, in feet 0.313 0 0.247 20 0.187 40 0.166 50 0.149 60 0.134 70 0.122 80 0.111 90 0.101 100 0.085 120 Disclaimer This spreadsheet solving the Hantush (1967) equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater infiltration basins" or to calculate values based on user-specified site conditions. Any changes made to the spreadsheet (other than values identified as user-specified) after transmission from the USGS could have unintended, undesirable consequences. These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report. The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet. If changes are made to the spreadsheet, the user is responsible for documenting the changes and justifying the results and conclusions. This spreadsheet will calculate the height of a groundwater mound beneath a stormwater infiltration basin. More information can be found in the U.S. Geological Survey Scientific Investigations Report 2010-5102 "Simulation of groundwater mounding beneath hypothetical stormwater infiltration basins". The user must specify infiltration rate (R), specific yield (Sy), horizontal hydraulic conductivity (Kh), basin dimensions (x, y), duration of infiltration period (t), and the initial thickness of the saturated zone (hi(0), height of the water table if the bottom of the aquifer is the datum). For a square basin the half width equals the half length (x = y). For a rectangular basin, if the user wants the water-table changes perpendicular to the long side, specify x as the short dimension and y as the long dimension. Conversely, if the user wants the values perpendicular to the short side, specify y as the short dimension, x as the long dimension. All distances are from the center of the basin. Users can change the distances from the center of the basin at which water-table aquifer thickness are calculated. Cells highlighted in yellow are values that can be changed by the user. Cells highlighted in red are output values based on user-specified inputs. The user MUST click the blue "Re-Calculate Now" button each time ANY of the user-specified inputs are changed otherwise necessary iterations to converge on the correct solution will not be done and values shown will be incorrect. Use consistent units for all input values (for example, feet and days) In the report accompanying this spreadsheet (USGS SIR 2010-5102), vertical soil permeability (ft/d) is assumed to be one-tenth horizontal hydraulic conductivity (ft/d). Re-Calculate Now 0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0 20 40 60 80 100 120 140 Groundwater Mounding, in feet 07/17/2026 LMJ/RPE POND 5 GROUNDWATER MOUNDING CALCULATIONS use consistent units (e.g. feet & days or inches & hours)Conversion Table Input Values inch/hour feet/day 1.0000 R Recharge (infiltration) rate (feet/day)0.67 1.33 0.150 Sy Specific yield, Sy (dimensionless, between 0 and 1) 10.00 K Horizontal hydraulic conductivity, Kh (feet/day)*2.00 4.00 5.000 x 1/2 length of basin (x direction, in feet) 40.657 y 1/2 width of basin (y direction, in feet)hours days 7.879 t duration of infiltration period (days)36 1.50 135.000 hi(0)initial thickness of saturated zone (feet) 135.309 h(max)maximum thickness of saturated zone (beneath center of basin at end of infiltration period) 0.309 Δh(max)maximum groundwater mounding (beneath center of basin at end of infiltration period) Ground- water Mounding, in feet Distance from center of basin in x direction, in feet 0.309 0 0.270 20 0.225 40 0.208 50 0.193 60 0.180 70 0.169 80 0.159 90 0.149 100 0.133 120 Disclaimer This spreadsheet solving the Hantush (1967) equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater infiltration basins" or to calculate values based on user-specified site conditions. Any changes made to the spreadsheet (other than values identified as user-specified) after transmission from the USGS could have unintended, undesirable consequences. These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report. The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet. If changes are made to the spreadsheet, the user is responsible for documenting the changes and justifying the results and conclusions. This spreadsheet will calculate the height of a groundwater mound beneath a stormwater infiltration basin. More information can be found in the U.S. Geological Survey Scientific Investigations Report 2010-5102 "Simulation of groundwater mounding beneath hypothetical stormwater infiltration basins". The user must specify infiltration rate (R), specific yield (Sy), horizontal hydraulic conductivity (Kh), basin dimensions (x, y), duration of infiltration period (t), and the initial thickness of the saturated zone (hi(0), height of the water table if the bottom of the aquifer is the datum). For a square basin the half width equals the half length (x = y). For a rectangular basin, if the user wants the water-table changes perpendicular to the long side, specify x as the short dimension and y as the long dimension. Conversely, if the user wants the values perpendicular to the short side, specify y as the short dimension, x as the long dimension. All distances are from the center of the basin. Users can change the distances from the center of the basin at which water-table aquifer thickness are calculated. Cells highlighted in yellow are values that can be changed by the user. Cells highlighted in red are output values based on user-specified inputs. The user MUST click the blue "Re-Calculate Now" button each time ANY of the user-specified inputs are changed otherwise necessary iterations to converge on the correct solution will not be done and values shown will be incorrect. Use consistent units for all input values (for example, feet and days) In the report accompanying this spreadsheet (USGS SIR 2010-5102), vertical soil permeability (ft/d) is assumed to be one-tenth horizontal hydraulic conductivity (ft/d). Re-Calculate Now 0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0 20 40 60 80 100 120 140 Groundwater Mounding, in feet 07/17/2026 LMJ/RPE POND 6 GROUNDWATER MOUNDING CALCULATIONS use consistent units (e.g. feet & days or inches & hours)Conversion Table Input Values inch/hour feet/day 1.0000 R Recharge (infiltration) rate (feet/day)0.67 1.33 0.150 Sy Specific yield, Sy (dimensionless, between 0 and 1) 10.00 K Horizontal hydraulic conductivity, Kh (feet/day)*2.00 4.00 5.000 x 1/2 length of basin (x direction, in feet) 25.000 y 1/2 width of basin (y direction, in feet)hours days 7.500 t duration of infiltration period (days)36 1.50 135.000 hi(0)initial thickness of saturated zone (feet) 135.215 h(max)maximum thickness of saturated zone (beneath center of basin at end of infiltration period) 0.215 Δh(max)maximum groundwater mounding (beneath center of basin at end of infiltration period) Ground- water Mounding, in feet Distance from center of basin in x direction, in feet 0.215 0 0.181 20 0.148 40 0.136 50 0.126 60 0.117 70 0.110 80 0.103 90 0.097 100 0.087 120 Disclaimer This spreadsheet solving the Hantush (1967) equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater infiltration basins" or to calculate values based on user-specified site conditions. Any changes made to the spreadsheet (other than values identified as user-specified) after transmission from the USGS could have unintended, undesirable consequences. These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report. The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet. If changes are made to the spreadsheet, the user is responsible for documenting the changes and justifying the results and conclusions. This spreadsheet will calculate the height of a groundwater mound beneath a stormwater infiltration basin. More information can be found in the U.S. Geological Survey Scientific Investigations Report 2010-5102 "Simulation of groundwater mounding beneath hypothetical stormwater infiltration basins". The user must specify infiltration rate (R), specific yield (Sy), horizontal hydraulic conductivity (Kh), basin dimensions (x, y), duration of infiltration period (t), and the initial thickness of the saturated zone (hi(0), height of the water table if the bottom of the aquifer is the datum). For a square basin the half width equals the half length (x = y). For a rectangular basin, if the user wants the water-table changes perpendicular to the long side, specify x as the short dimension and y as the long dimension. Conversely, if the user wants the values perpendicular to the short side, specify y as the short dimension, x as the long dimension. All distances are from the center of the basin. Users can change the distances from the center of the basin at which water-table aquifer thickness are calculated. Cells highlighted in yellow are values that can be changed by the user. Cells highlighted in red are output values based on user-specified inputs. The user MUST click the blue "Re-Calculate Now" button each time ANY of the user-specified inputs are changed otherwise necessary iterations to converge on the correct solution will not be done and values shown will be incorrect. Use consistent units for all input values (for example, feet and days) In the report accompanying this spreadsheet (USGS SIR 2010-5102), vertical soil permeability (ft/d) is assumed to be one-tenth horizontal hydraulic conductivity (ft/d). Re-Calculate Now 0.000 0.050 0.100 0.150 0.200 0.250 0 20 40 60 80 100 120 140 Groundwater Mounding, in feet 07/17/2026 LMJ/RPE APPENDIX E O&M PLAN BIKEFILL BIKE PARK 22147.01 August 2026 Project No. 22147.01 STORM DRAINAGE FACILITY MAINTENANCE PLAN BIKEFILL BIKE PARK BOZEMAN, MONTANA 59718 OVERVIEW NARRATIVE The purpose of this maintenance plan is to outline the necessary details related to ownership, responsibility, and cleaning schedule for the storm drainage facilities for the improvements to the Bikefill Bike Park project. This plan has been completed in accordance with The City of Bozeman Design and Construction Standards, dated October 2024. The site stormwater improvements have been designed with the intent to meet the current City of Bozeman drainage regulations for the entire site to the extent feasible. Specific site information and criteria are described below: OWNERSHIP OF FACILITIES City of Bozeman City of Bozeman will own all stormwater facilities which includes the underground detention and retention ponds, surface detention and retention ponds, piping, ditch, catch basins, and manholes within the site boundary. INSPECTION THRESHOLDS FOR CLEANING Inlet/Outlet Structures Maintenance and cleaning shall be performed if the following conditions exist: • Sediment fill 60 percent of the sump • Sediment accumulates within 6” of a pipe • Grates are more than 25 percent obstructed by sediment or debris. Infiltration Chamber Maintenance and cleaning shall be performed if the following conditions exist: • Sediment within the isolator row exceeds 3” in depth • Inlet grates are more than 25 percent obstructed by sediment or debris • Inspection ports become obstructed Storm Drain Piping Maintenance and cleaning shall be performed if the following conditions exist: • Sediment reduces the cross-sectional area by more than 25 percent • Debris restricts flow • CCTV inspection identifies excessive sediment accumulation, structural deficiencies, or root intrusion • Ponding indicates reduced hydraulic capacity Above Ground Detention/Retention Ponds Maintenance and cleaning shall be performed if the following conditions exist: • Sediment accumulation is greater than 25 percent of pond capacity • If noticeable bank erosion is present Drainage Ditches Maintenance and cleaning shall be performed if the following conditions exist: • Sediment accumulation is greater than 25 percent of cross-sectional area • Vegetation overgrowth is noticeable Boulder Pit Maintenance and cleaning shall be performed if the following conditions exist: • Sediment reaches the invert of the perforated pipe CLEANING Inlet/Outlet Structures To clean grate of structure, remove and dispose of debris clogging the grate. To clean the structure, use a vac truck to remove sediment and debris. Infiltration Chamber To clean isolator row, use a JetVac. Storm Drain Piping To clean drain piping use a JetVac. CCTV inspection is recommended following cleaning. Above Ground Detention/Retention Ponds To clean ponds, remove and dispose of debris within the pond. Mowing shall occur to manage vegetation. Drainage Ditches To clean drainage ditch, remove and dispose of debris within the ditch. Trim vegetation as necessary. Boulder Pit To clean boulder pit, use a JetVac. INSPECTION, MAINTENANCE, AND REPLACEMENT SCHEDULE Inlet/Outlet Structures • Inspection: Every 6 months and after storm events larger than 0.5 inches of precipitation • Maintenance: Clean grate of structure and vacuum sediment and debris out of the sump every 5 years or as needed based on inspection • Design Life/Replacement Schedule: 75 years Infiltration Chamber • Inspection: Every 6 months and after storm events larger than 0.5 inches of precipitation • Maintenance: Vacuum isolator row every 5 years or as needed based on inspection • Design Life/Replacement Schedule: 75 years Storm Drain Piping • Inspection: Every 6 months and after storm events larger than 0.5 inches of precipitation • Maintenance: Flush and clean piping every five years or as required based on inspection results • Design Life/Replacement Schedule: 50 years Above Ground Detention/Retention Ponds • Inspection: Every 6 months and after storm events larger than 0.5 inches of precipitation • Maintenance: Remove debris as needed. Remove accumulated sediment when storage capacity has been reduced by approximately 25 percent or as determined by inspection. • Design Life/Replacement Schedule: 150 years Drainage Ditches • Inspection: Every 6 months and after storm events larger than 0.5 inches of precipitation • Maintenance: Remove debris as needed. Remove accumulated sediment when storage capacity has been reduced by approximately 25 percent or as determined by inspection. • Design Life/Replacement Schedule: 150 years Boulder Pit • Inspection: Every 6 months and after storm events larger than 0.5 inches of precipitation • Maintenance: Remove accumulated sediment and debris as needed based on inspection findings. • Design Life/Replacement Schedule: 75 years RESPONSIBLE PARTY City of Bozeman City of Bozeman will be responsible for the inspection, maintenance, and replacement of all stormwater facilities located within the project limits. I agree to the above inspection, maintenance, and replacement schedule detailed above. Signature: __________________________________________ City of Bozeman Representative APPENDIX F TD&H GEOTECHNICAL REPORT BIKEFILL BIKE PARK 22147.01 MONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA JOB NO. B25-012-001 May 2025 REPORT OF GEOTECHNICAL INVESTIGATION CLIENT ENGINEER Gallatin Valley Land Trust 212 S Wallace Avenue, Suite 101 Bozeman, MT 59715 Craig Nadeau, PE Craig.nadeau@tdhengineering.com REPORT OF GEOTECHNICAL INVESTIGATION PROJECT NAME PROJECT LOCATION 406.761.3010 tdhengineering.com 1800 River Drive North Great Falls, MT 59401 GALLATIN VALLEY LAND TRUST BIKE PARK BOZEMAN, MONTANA Gallatin Valley Land Trust Bike Park Table of Contents Bozeman, Montana i Table of Contents 1.0 EXECUTIVE SUMMARY ......................................................................................................... 1 2.0 INTRODUCTION ..................................................................................................................... 2 2.1 Purpose and Scope .......................................................................................................... 2 2.2 Project Description ........................................................................................................... 2 3.0 SITE CONDITIONS ................................................................................................................. 3 3.1 Geology and Physiography .............................................................................................. 3 3.2 Surface Conditions ........................................................................................................... 3 3.3 Subsurface Conditions ..................................................................................................... 4 3.3.1 Soils ......................................................................................................................... 4 3.3.2 Ground Water ......................................................................................................... 5 4.0 ENGINEERING ANALYSIS .................................................................................................... 6 4.1 Introduction ....................................................................................................................... 6 4.2 Site Grading and Excavations.......................................................................................... 6 4.3 Conventional Shallow Foundations ................................................................................. 6 4.4 Toilet Vaults ...................................................................................................................... 7 4.5 Concrete Flatwork ............................................................................................................ 7 4.6 Pavements ....................................................................................................................... 7 5.0 RECOMMENDATIONS ........................................................................................................... 9 5.1 Site Grading and Excavations.......................................................................................... 9 5.2 Conventional Shallow Foundations ............................................................................... 10 5.3 Toilet Vaults .................................................................................................................... 11 5.4 Concrete Flatwork .......................................................................................................... 11 5.5 Pavements ..................................................................................................................... 12 5.6 Continuing Services ....................................................................................................... 13 6.0 SUMMARY OF FIELD AND LABORATORY STUDIES ....................................................... 14 6.1 Field Explorations ........................................................................................................... 14 6.2 Laboratory Testing ......................................................................................................... 14 7.0 LIMITATIONS ........................................................................................................................ 16 Gallatin Valley Land Trust Bike Park Appendix Bozeman, Montana ii APPENDIX ♦ Test Pit Location Map (Figure 1) ♦ Logs of Exploratory Test Pits (Figures 2 through 11) ♦ Laboratory Test Data (Figures 12 through 21) ♦ LTTPBind Online PG Asphalt Binder Analysis Summary ♦ Soil Classification and Sampling Terminology for Engineering Purposes ♦ Classification of Soils for Engineering Purposes Gallatin Valley Land Trust Bike Park Executive Summary Bozeman, Montana Page 1 GEOTECHNICAL REPORT GALLATIN VALLEY LAND TRUST BIKE PARK BOZEMAN, MONTANA 1.0 EXECUTIVE SUMMARY A geotechnical investigation was performed for the proposed Gallatin Valley Land Trust (GVLT) bike park to be located between the existing Snowfill Recreation Area and the City of Bozeman Solid Waste Facility on the east side of McIlhattan Road in Bozeman, Montana. The geotechnical investigation for this project encountered varying subsurface conditions at each of the planned development areas. The lower portion of the property, where the planned access road and parking lots are to be built, encountered relatively thick topsoil overlying lean clays. Portions of the lean clay along the north side of the proposed parking lot contain abundant cobbles and boulders up to two-foot in diameter within the top four feet of the soil profile. This material is black in color and may be fill; however, no deleterious materials were observed within this zone, and it was generally consistent. At a depth of approximately four feet, the black soil transition to a light tan lean clay and similar soil extends to depths of more than eight feet at most locations. On the east side of the property, the proposed HUB is to be built on top of the existing hill. This area of the project anticipates construction of various small support structures, including shade canopies, rest rooms, equipment storage structures, etc. Subsurface conditions in this area are very different from those seen below and consist of limited surficial topsoil and lean clay overlying clayey gravel with sand extending to depths of at least 7.0 feet. The site poses no significant geotechnical concerns which would preclude the planned construction. The gravel encountered in the HUB area of the project, where the planned accessory structures will be built, is a superior bearing stratum and is suitable for the use of conventional foundation and slab systems. The surficial clay soils should be excavated from beneath all structures; however, over- excavation should be limited as the lean clay extended to a depth of 2.5 feet at one location but generally was only one foot or less at the ground surface. Subgrade materials within the planned parking lot are anticipated to consist of fine-grained clay soils with low permeability and relatively poor strength properties. Additionally, this material will be encountered at moistures which will inhibit proper compaction, making an even weaker subgrade; thus, the need for thicker pavement sections should be anticipated for this project. Gallatin Valley Land Trust Bike Park Introduction Bozeman, Montana Page 2 2.0 INTRODUCTION 2.1 Purpose and Scope This report presents the results of our geotechnical study for the proposed Gallatin Valley Land Trust (GVLT) bike park to be located between the existing Snowfill Recreation Area and the City of Bozeman Solid Waste Facility on the east side of McIlhattan Road in Bozeman, Montana. The purpose of the geotechnical study is to determine the general surface and subsurface conditions at the proposed site and to develop geotechnical engineering recommendations for support of the proposed accessory structures and design of related facilities. This report describes the field work and laboratory analyses conducted for this project, the surface and subsurface conditions encountered, and presents our recommendations for the proposed foundations and related site development. Our field work included excavating ten test pits across the proposed site. Samples were obtained from the test pits and returned to our Great Falls laboratory for testing. Laboratory testing was performed on selected soil samples to determine engineering properties of the subsurface materials. The information obtained during our field investigations and laboratory analyses was used to develop recommendations for the site development. 2.2 Project Description It is our understanding that the proposed project consists of an access road and parking lot located on the west end of the property with a connection to McIlhattan Road. Limited support structures are also anticipated in the central HUB portion of the project and are anticipated to be limited to small canopy structures, rest rooms utilizing a sealed concrete vault, and small maintenance shed or building. Structural loads had not been developed at the time of this report. However, for the purpose of our analysis, we have assumed that loads to the various support structures will be less than 2,000 pounds per lineal foot for walls and less than 50-kips for columns. If the assumed design values presented above vary from the actual project parameters, the recommendations presented in this report should be reevaluated. Gallatin Valley Land Trust Bike Park Site Conditions Bozeman, Montana Page 3 3.0 SITE CONDITIONS 3.1 Geology and Physiography The site is geologically characterized as primarily gravel (Qgr & QTgr). The deposits consist of variable deposits ranging from pebble to boulder size and including sand, silt, and clay. Deposits are dominantly associated with alluvial terrace, abandoned channel and floodplain, remnant alluvial fan, and local glacial outwash deposits. These gravels generally overlie upper tertiary sediments and sedimentary rock consisting of conglomerate, tuffaceous sandstone and siltstone, marlstone, and equivalent sediment and ash beds. GEOLOGIC MAP OF MONTANA, EDITION 1.0 (2007) MONTANA BUREAU OF MINES & GEOLOGY 3.2 Surface Conditions The proposed project site is located between the existing Snowfill Recreation Area and the City of Bozeman Solid Waste Facility on the east side of McIlhattan Road in Bozeman, Montana. At the time of our investigation, the site was undeveloped and vegetated with native grasses. Based on background information and site observations, the site generally slopes down to the west at slopes estimated to range from two to ten percent. The topography is best described as gently to moderately sloping. Gallatin Valley Land Trust Bike Park Site Conditions Bozeman, Montana Page 4 3.3 Subsurface Conditions 3.3.1 Soils The subsurface soil conditions appear to be somewhat variable at the two planned development areas but relatively consistent within each individual area based on our exploratory excavating and soil sampling. In general, the subsurface soil conditions encountered within the test pits at the planned HUB location (site for planned accessory structures) consist of 0.8 to 2.5 feet of surficial topsoil and lean clay overlying clayey gravel with sand. Similar gravels extend to depths of more than 7.0 feet, the maximum depth investigated at this location. In the lower portion of the site near the planned parking lot, subsurface soils consist of lean clay extending to depths of at least 7.0 to 8.0 feet. The north side of the planned parking lot encountered black lean clay containing large cobbles and boulders (up to 2-foot in diameter) extending to depths of approximately four feet. The underlying lean clay was tan in color and contained little or no gravel. The upper four feet may represent fill material; however, it contained no visible deleterious materials and was relatively consistent between test pit locations. The subsurface soils are described in detail on the enclosed test pit logs and are summarized below. The stratification lines shown on the logs represent approximate boundaries between soil types, and the actual in situ transition may be gradual vertically or discontinuous laterally. LEAN CLAY Lean clay is the dominant soil type encountered on site and extends throughout the majority of the investigated depth in the lower site planned for a parking lot. The lean clay contains varying amounts of sand, varying thickness of topsoil, and scattered cobbles and boulders up to 2 feet in diameter in the top three to four feet. The clay is considered soft to firm based on observations during excavation and the relative ease of digging. Three samples of these materials obtained from various test pits resulted in classifications of either sandy lean clay or lean clay containing between 0.3 and 2.9 percent gravel, between 5.9 and 40.5 percent sand, and between 58.4 and 93.8 percent fines (clay and silt). The same samples exhibited liquid limits ranging from 33 to 39 percent and plasticity indices ranging from 15 to 20 percent. The natural moisture contents varied from 17.5 to 29.0 percent and averaged 22.6 percent. A single bulk sample was tested to assess its strength as a subgrade for the pavement. A standard proctor, performed in accordance with ASTM D698 resulted in a maximum dry density of 110.3 pounds per cubic foot (pcf) when compacted at the optimum moisture content of 15.8 percent. Comparing the in-situ moistures to the results of the proctor test, the native clays exhibit moistures which are above optimum by as much as 10 percent, Gallatin Valley Land Trust Bike Park Site Conditions Bozeman, Montana Page 5 which will inhibit compaction resulting in lower CBR values. A CBR test performed on the sample in accordance with ASTM D1883 indicates a design CBR value of 3.1 percent for prepared clay subgrade assuming only 90 percent compaction to reflect the over-optimum condition. CLAYEY GRAVEL WITH SAND Clayey gravel with sand was encountered in five test pits (TP-1, TP-6 and TP-8 through TP- 10). In TP-1, the gravel was observed as a limited layer sandwiched between lean clay from approximately 3.0 to 4.0 feet. All other test pits terminated within the gravel at depths of 7.0 to 8.0 feet. The gravels were not encountered until a depth of 7.5 feet in TP-6 but were observed at depths as shallow as one foot in TP-8 through TP-10 located on the upper terrace of the property. The gravels appear relatively dense based on the observations during excavation. A single sample contained 60.6 percent gravel, 26.7 percent sand, and 12.7 percent fines. The fines were classified as lean clay and exhibited a liquid limit of 35 percent and a plasticity index of 11 percent. The natural moisture content was 10.8 percent. 3.3.2 Ground Water Ground water was not encountered within the test pits to depths ranging from 7.0 to 8.0 feet below the ground surface. The presence or absence of observed ground water may be directly related to the time of the subsurface investigation. Numerous factors contribute to seasonal ground water occurrences and fluctuations, and the evaluation of such factors is beyond the scope of this report. Gallatin Valley Land Trust Bike Park Engineering Analysis Bozeman, Montana Page 6 4.0 ENGINEERING ANALYSIS 4.1 Introduction The site poses no significant geotechnical concerns which would preclude the planned construction. The gravel encountered in the area of the planned accessory structures is a superior bearing stratum and is suitable for the use of conventional foundation and slab systems. The surficial clay soils should be excavated from beneath all structures; however, similar materials extend to depths of 2.5 feet or less, and necessary subexcavation will be limited. Subgrade materials within the planned parking lot are anticipated to consist of fine-grained clay soils with low permeability and relatively poor strength properties. Additionally, this material will be encountered at moistures which will inhibit proper compaction making an even weaker subgrade; thus, the need for thicker pavement sections should be anticipated. 4.2 Site Grading and Excavations The ground surface at the proposed site varies from nearly level to moderately sloping down toward the west at slopes estimated to range from approximately two to ten percent. Based on our field work, primarily lean clay soils with varying sand contents and occasional large cobbles and boulders up to two feet in diameter are anticipated in the parking lot area of the project. However, in the upper terrace where the accessory structures are proposed, foundation excavations are likely to encounter only limited topsoil and lean clay overlying relatively dense clayey gravels. Based on the test pits, ground water should be below the anticipated depths of footing and utility excavations; however, depending on the time of year, occasional pockets of trapped or perched ground water associated with recent precipitation events should be anticipated. 4.3 Conventional Shallow Foundations This project contains only small accessory structures such as canopies, restrooms, and potentially a small maintenance shed in the central HUB portion of the project. Considering the subsurface conditions encountered in this portion of the site, these structures can be supported on conventional shallow foundations or frost-protected thickened-edge monolithic slabs supported on properly compacted native gravels. Two of the three test pits in this area encountered approximately 12 inches of topsoil directly over native gravels; however, the third test pit encountered similar topsoil overlying lean clay extending to a depth of 2.5 feet. To ensure inform conditions, it is recommended that all surface clay be removed from beneath foundations for structures. When frost-depth footings are utilized, no additional excavation and replacement is anticipated; however, if thickened-edge slab construction is considered, localized areas of over-excavation and replacement of the surficial clay should be anticipated. Based on our experience, the theory of elasticity, and using an allowable bearing pressure of no greater than 3,000 psf, we estimate the total settlement for footings bearing on properly compacted Gallatin Valley Land Trust Bike Park Engineering Analysis Bozeman, Montana Page 7 native gravels will be less than ¾-inch. Differential settlement within the limits of individual structures should be on the order of one-half this magnitude. The lateral resistance of spread footings is controlled by a combination of sliding resistance between the footing and the foundation material at the base of the footing and the passive earth pressure against the side of the footing in the direction of movement. Design parameters are given in the recommendations section of this report. 4.4 Toilet Vaults Walls for underground toilet vaults for this project will be subjected to horizontal loading due to lateral earth pressures. The lateral earth pressures are a function of the natural and backfill soil types and acceptable wall movements, which affect soil strain to mobilize the shear strength of the soil. More soil movement is required to develop greater internal shear strength and lower the lateral pressure on the wall. To fully mobilize strength and reduce lateral pressures, soil strain and allowable wall rotation must occur, which is not possible for the anticipated vault structures; thus, all structures anticipated for this project should utilize at-rest conditions indicative of zero rotation. The distribution of the lateral earth pressures on the structure depends on soil type and wall movements or deflections. In most cases, a triangular pressure distribution is satisfactory for design and is usually represented as an equivalent fluid unit weight. Design parameters are given in the recommendations section of this report. 4.5 Concrete Flatwork The natural on-site soils, exclusive of topsoil, are suitable to support lightly to moderately loaded, slab-on-grade construction. A leveling course of granular fill directly beneath the slab is recommended to provide a structural cushion, a capillary-break from the subgrade, and a drainage medium. Due to the relatively soft clay soils anticipated in some areas as well as the high moistures in the clay which will impact compaction, we recommended a minimum of 12 inches of compacted base course gravel beneath slabs for this project. 4.6 Pavements A pavement section is a layered system designed to distribute concentrated traffic loads to the subgrade. Performance of the pavement structure is directly related to the physical properties of the subgrade soils and the magnitude and frequency of traffic loadings. Pavement design procedures are based on strength properties of the subgrade and pavement materials, along with the design traffic conditions. Traffic information was not available at the time of this report. We have assumed that traffic for the parking lot will be limited to passenger-type vehicles with a total 20-year design equivalent single axle load (ESAL) not to exceed 50,000. Gallatin Valley Land Trust Bike Park Engineering Analysis Bozeman, Montana Page 8 The anticipated subgrade material is the lean clay which is classified as an A-6 soil in accordance with the American Association of State Highway and Transportation Officials (AASHTO) classification. AASHTO considers this soil type to be a fair to poor subgrade due to its moisture sensitivity, low strength, and poor drainage properties. Typical California Bearing Ratio (CBR) values for this type of soil are less than five percent. A laboratory CBR test resulted in a CBR of 3.1 percent assuming compaction levels can reach at least 90 percent. While subgrade moistures are anticipated to be high and impact the ability to reach conventional compaction levels, it will be necessary to compact the subgrade to the maximum extent possible during construction. Compaction should utilize only static methods as vibration can further reduce the stability of the clay soils at the moistures anticipated. Due to the anticipated low compaction of the subgrade soils, the inclusion of a geotextile to provide separation as well as reinforcing properties is advised. The geotextile will prevent the upward migration of fines and the loss of aggregate into the subgrade, thereby prolonging the structural integrity and performance of the pavement section as well as help to reinforce to soft subgrade helping to improve performance. The pavement section presented in this report is based on the laboratory determined CBR value of 3.1 percent, assumed traffic loadings, recommended pavement section design information presented in the Asphalt Institute and AASHTO Design Manuals, and our past pavement design experience in Bozeman. Gallatin Valley Land Trust Bike Park Recommendations Bozeman, Montana Page 9 5.0 RECOMMENDATIONS 5.1 Site Grading and Excavations 1. All topsoil and organic material should be removed from the footprint of planned structures and pavement areas and any areas to receive site grading fill. Based on our field investigation, removing approximately one foot of surface material should be adequate to remove most problematic organics; however, additional stripping depth may be warranted in some areas once actual stripping operations are performed. 2. All fill and backfill should be non-expansive, free of organics and debris and should be approved by the project geotechnical engineer. The on-site soils, exclusive of topsoil, are suitable for use as backfill and general site grading fill on this project. All fill should be placed in uniform lifts not exceeding 8 inches in thickness for fine- grained soils and not exceeding 12 inches for granular soils. All materials compacted using hand compaction methods or small walk-behind units should utilize a maximum lift thickness of 6 inches to ensure adequate compaction throughout the lift. All fill and backfill shall be moisture conditioned to near the optimum moisture content and compacted to the following percentages of the maximum dry density determined by a standard proctor test which is outlined by ASTM D698 or equivalent (e.g. ASTM D4253-D4254). a) Below Foundations & Slabs ........................................................ 98% b) Foundation & Vault Backfill ......................................................... 95% c) Subgrade Beneath Pavements & Concrete Flatwork ................. 90% d) Pavement & Concrete Base or Subbase .................................... 95% For your consideration, verification of compaction requires laboratory proctor tests to be performed on a representative sample of the soil prior to construction. These tests can require up to one week to complete (depending on laboratory backlog) and this should be considered when coordinating the construction schedule to ensure that delays in construction or additional testing expense is not required due to laboratory processing times or rush processing fees. 3. Develop and maintain site grades which will rapidly drain surface and roof runoff away from foundation and subgrade soils; both during and after construction. The final site grading shall conform to the grading plan, prepared by others to satisfy the minimum requirements of the applicable building codes. 4. It is the responsibility of the Contractor to provide safe working conditions in connection with underground excavations. Temporary construction excavations greater than four feet in depth, which workers will enter, will be governed by OSHA Gallatin Valley Land Trust Bike Park Recommendations Bozeman, Montana Page 10 guidelines given in 29 CFR, Part 1926. The contractor is responsible to provide an OSHA knowledgeable individual during all excavation activities to regularly assess the soil conditions and ensure that all necessary safety precautions are implemented and followed. 5.2 Conventional Shallow Foundations The design and construction criteria below should be observed for a spread footing foundation system. The construction details should be considered when preparing the project documents. 5. All footings or thickened-edge foundations should be supported on properly compacted native gravels and should be designed for a maximum allowable soil bearing pressure not exceeding 3,000 psf provided settlements as outlined in the Engineering Analysis are acceptable. The need for over-excavation is not anticipated with conventional frost depth foundations but may be needed with thickened-edge slabs. When required, the limits of over-excavation and replacement with compacted structural fill should extend at least 12 inches beyond the foundations in all directions. 6. Soils disturbed below the planned depths of footing excavations should either be re- compacted or be replaced with suitable compacted backfill approved by the geotechnical engineer. 7. Footings shall be sized to satisfy the minimum requirements of the applicable building codes while not exceeding the maximum allowable bearing pressure provided in Item 5 above. 8. Exterior footings and footings beneath unheated areas should be placed at least 48 inches below finished exterior grade for frost protection. For thickened-edge slabs, use of rigid board, extruded polystyrene insulation (XEPS) is recommended to provide adequate frost protection. One inch of XEPS is approximately equivalent to 1 foot of soil cover. 9. The bottom of the footing excavations should be free of cobbles and boulders to avoid stress concentrations acting on the base of the footings. Incorporation of a thin leveling course between the concrete and the native gravels may be required if the surface of the native gravels cannot be rolled smooth. 10. Lateral loads are resisted by sliding friction between the footing base and the supporting soil and by lateral pressure against the footings opposing movement. For design purposes, a friction coefficient of 0.45 and a lateral resistance pressure of 250 psf per foot of depth are appropriate for footings bearing on and backfilled with properly compacted native gravels. Gallatin Valley Land Trust Bike Park Recommendations Bozeman, Montana Page 11 11. A representative of the project geotechnical engineer should be retained to observe all footing excavations and backfill phases prior to the placement of concrete formwork. 5.3 Toilet Vaults The design and construction criteria presented below should be observed for design of toilet vault structures for this project. The construction details should be considered when preparing the project documents. 12. Concrete sealed vault structures should be designed for a lateral earth pressure computed on the basis of an at-rest equivalent fluid unit weight of 60 pcf for backfill consisting of properly compacted native gravels. 13. Backfill should be selected, placed, and compacted per Item 2 above. Care should be taken not to over-compact the backfill since this could cause excessive lateral pressure on the walls. Only hand-operated compaction equipment should be used within 5 feet of vaults. 5.4 Concrete Flatwork 14. For normally loaded, exterior concrete flatwork, a cushion course consisting of free- draining, crushed gravel should be placed beneath the concrete and compacted to the requirements of Item 2 above. A minimum cushion course thickness of 12 inches, or down to native gravels, is recommended when constructed over native lean clay soils. Exterior flatwork which will be exposed to seasonal freezing conditions will perform better by completely removing and replacing the lean clay soils and supporting the concrete on compacted gravels extending to native gravels. The existing lean clay is considered frost susceptible and carries the highest risk of adverse slab performance when left in place beneath unheated structures. 15. Cushion course materials utilized beneath slab-on-grade applications should conform to the requirements outlined in Section 02235 of the Montana Public Works Standard Specifications (MPWSS). All gradation outlined in this specification are acceptable for this application. Prior to placing the cushion course, the upper six inches of subgrade should be compacted per Item 2. Gallatin Valley Land Trust Bike Park Recommendations Bozeman, Montana Page 12 5.5 Pavements 16. The following pavement section or an approved equivalent section should be selected in accordance with the discussions in the Engineering Analysis. Pavement Component Component Thickness Asphaltic Concrete Pavement 3” Crushed Base Course 4” Crushed Subbase Course 8” Total 15” 17. Crushed base courses shall conform to the material properties outlined in Section 02235 of the Montana Public Works Standard Specifications (MPWSS). All gradations outlined in this specification are acceptable for this application based on the local availability and contractor preference. Crushed subbase courses shall conform to material properties outlined in Section 02234 of the MPWSS. All gradations outlined in this specification are acceptable for this application based on local availability and contractor preference. 18. Where the existing grades will be raised more than the thickness of the pavement section, all fill should be placed, compacted and meet the general requirements given in Item 2 above. 19. A geotextile is recommended between the pavement section and the prepared subgrade to prevent the migration of fines upward into the gravel and the loss of aggregate into the subgrade. Either a Mirafi HP570 or Mirafi RS380i are recommended to achieve both the separation and reinforcing properties warranted for this project. 20. Ideally, the asphaltic cement should be a Performance Graded (PG) binder having the following minimum high and low temperature values based on the desired pavement reliability. Reliability Min. High Temp Rating Min. Low Temp Rating 50% 35.8 -23.8 98% 39.8 -32.6 Gallatin Valley Land Trust Bike Park Recommendations Bozeman, Montana Page 13 The use of a PG 58-28 grade oil is advised for all pavements on this project. This oil will provide a reliability of approximately 80 percent which is generally adequate for most low volume parking lot applications. 5.6 Continuing Services Three additional elements of geotechnical engineering service are important to the successful completion of this project. 21. Consultation between the geotechnical engineer and the design professionals during the design phases is highly recommended. This is important to ensure that the intentions of our recommendations are incorporated into the design, and that any changes in the design concept consider the geotechnical limitations dictated by the on-site subsurface soil and ground water conditions. 22. Observation, monitoring, and testing during construction is required to document the successful completion of all earthwork and foundation phases. A geotechnical engineer from our firm should be retained to observe the excavation, earthwork, and foundation phases of the work to determine that subsurface conditions are compatible with those used in the analysis and design. 23. During site grading, placement of all fill and backfill should be observed and tested to confirm that the specified density has been achieved. We recommend that the Owner maintain control of the construction quality control by retaining the services of an experienced construction materials testing laboratory. We are available to provide construction inspection services as well as materials testing of compacted soils and the placement of Portland cement concrete and asphalt. In the absence of project specific testing frequencies, TD&H recommends the following minimum testing frequencies be used: Compaction Testing Beneath Column Footings 1 Test per Footing per Lift Beneath Wall Footings 1 Test per 50 LF of Wall per Lift Beneath Slabs 1 Test per 1,500 SF per Lift Foundation Backfill 1 Test per 100 LF of Wall per Lift Parking Lot & Access Roads 1 Test per 2,500 SF per Lift LF = Lineal Feet SF = Square Feet Gallatin Valley Land Trust Bike Park Summary of Field & Laboratory Studies Bozeman, Montana Page 14 6.0 SUMMARY OF FIELD AND LABORATORY STUDIES 6.1 Field Explorations The field exploration program was conducted on April 1, 2025. A total of ten test pits were excavated to depths ranging from 7.0 to 8.0 feet at the locations shown on Figure 1 to observe subsurface soil and ground water conditions. The tests pits were excavated using a CAT 310 excavator. The subsurface exploration and sampling methods used are indicated on the attached test pit logs. The test pits were logged by Mr. Craig Nadeau, PE of TD&H Engineering. The location of the test pits was recorded using a Trimble handheld GPS unit. The locations shown are accurate to within 18 inches of the actual field location. Samples of the subsurface materials were taken from excavated spoils at discrete changes int he subsurface stratigraphy. Logs of all test pits, which include soil descriptions and sample depths are presented on the Figures 2 through 11. No evidence of ground water was encountered. Excavation equipment remained dry, free water was not observed on excavated spoils, and no visible water was seen in completed test pits or seeping from sidewalls. 6.2 Laboratory Testing Samples obtained during the field exploration were returned to our materials laboratory where they were observed and visually classified in general accordance with ASTM D2487, which is based on the Unified Soil Classification System. Representative samples were selected for testing to determine the engineering and physical properties of the soils in general accordance with ASTM or other approved procedures. Tests Conducted: To determine: Natural Moisture Content Representative moisture content of soil at the time of sampling. Grain-Size Distribution Particle size distribution of soil constituents describing the percentages of clay/silt, sand and gravel. Atterberg Limits A method of describing the effect of varying water content on the consistency and behavior of fine-grained soils. Moisture-Density Relationship A relationship describing the effect of varying moisture content and the resulting dry unit weight at a given compactive effort. Provides the optimum moisture content and the maximum dry unit weight. Also called a Proctor Curve. Gallatin Valley Land Trust Bike Park Summary of Field & Laboratory Studies Bozeman, Montana Page 15 California Bearing Ratio The measure of a subgrade’s or granular base’s ability to resist deformation due to penetration during a saturated condition. Used to assist in pavement thickness designs. The laboratory testing program for this project consisted of 12 moisture-visual analyses, 4 sieve (grain-size distribution) analyses, and 4 Atterberg Limits analyses. The results of the water content analyses are presented on the test pit logs, Figures 2 through 11. The grain-size distribution curves and Atterberg limits are presented on Figures 12 through 19. In addition, one proctor (moisture- density) test and one California Bearing Ratio (CBR) test were performed. The CBR and moisture density relationships are shown on Figures 20 and 21. Gallatin Valley Land Trust Bike Park Limitations Bozeman, Montana Page 16 7.0 LIMITATIONS This report has been prepared in accordance with generally accepted geotechnical engineering practices in this area for use by the client for design purposes. The findings, analyses, and recommendations contained in this report reflect our professional opinion regarding potential impacts the subsurface conditions may have on the proposed project and are based on site conditions encountered. Our analysis assumes that the results of the exploratory test pits are representative of the subsurface conditions throughout the site, that is, that the subsurface conditions everywhere are not significantly different from those disclosed by the subsurface study. Unanticipated soil conditions are commonly encountered and cannot be fully determined by a limited number of test pits and laboratory analyses. Such unexpected conditions frequently require that some additional expenditures be made to obtain a properly constructed project. Therefore, some contingency fund is recommended to accommodate such potential extra costs. The recommendations contained within this report are based on the subsurface conditions observed in the test pits and are subject to change pending observation of the actual subsurface conditions encountered during construction. TD&H cannot assume responsibility or liability for the recommendations provided if we are not provided the opportunity to perform limited construction inspection and confirm the engineering assumptions made during our analysis. A representative of TD&H should be retained to observe all construction activities associated with subgrade preparation, foundations, and other geotechnical aspects of the project to ensure the conditions encountered are consistent with our assumptions. Unforeseen conditions or undisclosed changes to the project parameters or site conditions may warrant modification to the project recommendations. Long delays between the geotechnical investigation and the start of construction increase the potential for changes to the site and subsurface conditions which could impact the applicability of the recommendations provided. If site conditions have changed because of natural causes or construction operations at or adjacent to the site, TD&H should be retained to review the contents of this report to determine the applicability of the conclusions and recommendations provide considering the time lapse or changed conditions. Misinterpretation of the geotechnical information by other design team members is possible and can result in costly issues during construction and with the final product. Our geotechnical engineers are available upon request to review those portions of the plans and specifications which pertain to earthwork and foundations to determine if they are consistent with our recommendations and to suggest necessary modifications as warranted. This service was not included in the original scope of the project and will require additional fees for the time required for specification and plan document review and comment. In addition, TD&H should be involved throughout the construction process to observe construction, particularly the placement and compaction of all fill, preparation of all foundations, and all other geotechnical aspects. Retaining the geotechnical engineer who prepared your geotechnical report to provide construction observation is the most effective method of managing the risks associated with unanticipated conditions. Gallatin Valley Land Trust Bike Park Limitations Bozeman, Montana Page 17 This report was prepared for the exclusive use of the owner and architect and/or engineer in the design of the subject facility. It should be made available to prospective contractors and/or the contractor for information on factual data only and not as a warranty of subsurface conditions such as those interpreted from the test pit logs and presented in discussions of subsurface conditions included in this report. Prepared by: Reviewed by: Craig Nadeau PE & Principal Peter Klevberg PE Geotechnical Manager Geotechnical Engineer TD&H ENGINEERING TD&H ENGINEERING TEST PIT 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, black, moist Lean CLAY with Sand, firm, light brown, moist Clayey GRAVEL with Sand, relatively dense, light brown, moist Sandy Lean CLAY, appears firm, light brown, moist Bottom of Test Pit 0.3 3.0 4.0 7.0 Ground water not encoun- tered G LEGEND LOG OF TEST PIT TP-01Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 2 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, black, moist Lean CLAY, appears soft to firm, brown, moist Bottom of Test Pit 0.8 7.0 Ground water not encoun- tered G G LEGEND LOG OF TEST PIT TP-02Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 3 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, black, moist, abundant organics in top 9 inches Gravelly Lean CLAY, appears firm, black, moist, 2-ft minus cobbles and boulders Lean CLAY, appears firm, light brown, moist Bottom of Test Pit 1.5 4.0 8.0 Ground water not encoun- tered G LEGEND LOG OF TEST PIT TP-03Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 4 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, black, moist, abundant organics in top 12 inches Gravelly Lean CLAY, appears firm, dark brown to black, moist, 2-ft minus cobbles and boulders Lean CLAY with Sand, appears firm, brown, moist, scattered gravel Bottom of Test Pit 1.0 4.0 7.5 Ground water not encoun- tered G G LEGEND LOG OF TEST PIT TP-04Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 5 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, black, moist, abundant organics in top 12 inches Sandy Lean CLAY, appears firm, brown, moist - See Figures 20 and 21 for proctor and CBR results - Large cobbles and boulders at approx 4.0-ft Lean CLAY, appears firm, light brown, moist Bottom of Test Pit 2.0 4.0 7.5 Ground water not encoun- tered G G LEGEND LOG OF TEST PIT TP-05Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 6 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, black, moist, abundant organics in top 12 inches Gravelly Lean CLAY, relatively soft, black, moist, 2-ft minus cobbles and boulders Lean CLAY with Sand, appears firm, light brown, moist Clayey GRAVEL with Sand, relatively dense, light brown, moist Bottom of Test Pit 1.5 4.0 7.5 8.0 Ground water not encoun- tered G LEGEND LOG OF TEST PIT TP-06Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 7 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, black, moist, abundant organics in top 12 inches Sandy Lean CLAY, relatively soft, black, moist Lean CLAY with Sand, appears firm, light brown, moist Bottom of Test Pit 1.5 3.5 7.0 Ground water not encoun- tered G G LEGEND LOG OF TEST PIT TP-07Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 8 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, dark brown, moist Sandy Lean CLAY, appears soft to firm brown, moist Clayey GRAVEL with Sand, relatively dense, brown, moist Bottom of Test Pit 1.0 2.5 8.0 Ground water not encoun- tered G G LEGEND LOG OF TEST PIT TP-08Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 9 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, dark brown, very moist Clayey GRAVEL with Sand, relatively dense, brown, moist, 12-inch minus Bottom of Test Pit 0.8 7.0 Ground water not encoun- tered LEGEND LOG OF TEST PIT TP-09Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 10 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 1.5 3 4.5 6 7.5 9 10.5 TOPSOIL: Lean CLAY, relatively soft, dark brown, very moist Clayey GRAVEL with Sand, relatively dense, brown, moist, 8-inch minus Bottom of Test Pit 1.0 7.0 Ground water not encoun- tered G LEGEND LOG OF TEST PIT TP-10Atterberg Limits Field Moisture content GVLT Bike Park Bozeman, MontanaGroundwater Level Grab/composite sample Logged by:Craig Nadeau, PE Excavated by:Earth Surgeons CAT 310 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. 4-1-2025 B25-012-001 Figure No. 11 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Snow Covered Native Grass SURFACE ELEVATION:Not Measured DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 Tested By: BC Checked By: Particle Size Distribution Report ASTM C117 & C136 PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 0.0 0.3 0.5 1.2 4.2 93.86 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description Atterberg Limits Coefficients Classification Test Remarks Sample Date:Location: TP-03 Sample Number: A-31495 Depth: 5.0 - 6.0 ft Client: Project: Project No: Figure Sieve Size or Diam. (mm.) Finer (%) Spec.* (%) Out of Spec. (%) Pct. of Fines Lean CLAY 3/8 #4 #10 #20 #40 #60 #80 #100 #200 100.0 99.7 99.2 98.6 98.0 97.5 97.0 96.7 93.8 19 39 20 CL A-6(19) Report No. A-31495-206 Report Date: 4-23-2025 F.M.=0.09 Gallatin Valley Land Trust GVLT Bike Park Bozeman, Montana B25-012-001 PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= *(no specification provided) 12 Tested By: BS/BC Checked By: Particle Size Distribution Report ASTM C117 & C136 PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 0.1 1.0 3.4 15.1 22.0 58.46 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description Atterberg Limits Coefficients Classification Test Remarks Sample Date:Location: TP-05 Sample Number: A-31498 Depth: 2.0 ft Client: Project: Project No: Figure Sieve Size or Diam. (mm.) Finer (%) Spec.* (%) Out of Spec. (%) Pct. of Fines Sandy Lean CLAY 1 3/4" 1/2" 3/8" #4 #10 #20 #40 #60 #80 #100 #200 100.0 99.9 99.7 99.6 98.9 95.5 89.7 80.4 71.8 67.2 64.7 58.4 96.6 90.7 81.3 72.6 68.0 65.5 59.0 18 33 15 0.8739 0.5812 0.0905 CL A-6(6) Report No. A-31498-206 Report Date: 4-12-2025 F.M.=0.88 Gallatin Valley Land Trust GVLT Bike Park Bozeman, Montana B25-012-001 PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= *(no specification provided) 13 Tested By: BS Checked By: Particle Size Distribution Report ASTM C117 & C136 PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 0.0 2.9 5.2 15.9 16.6 59.46 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description Atterberg Limits Coefficients Classification Test Remarks Sample Date:Location: TP-07 Sample Number: A-31501 Depth: 2.0 ft Client: Project: Project No: Figure Sieve Size or Diam. (mm.) Finer (%) Spec.* (%) Out of Spec. (%) Pct. of Fines Sandy Lean CLAY 3/8" #4 #10 #20 #40 #60 #80 #100 #200 100.0 97.1 91.9 84.2 76.0 70.5 67.4 65.3 59.4 21 38 17 1.5765 0.9190 0.0804 CL A-6(8) Report No. A-31501-206 Report Date: 4-23-2025 F.M.=1.05 Gallatin Valley Land Trust GVLT Bike Park Bozeman, Montana B25-012-001 PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= *(no specification provided) 14 Tested By: IR/JB Checked By: Particle Size Distribution Report ASTM C117 & C136 PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 13.6 27.5 19.5 5.6 8.9 12.2 12.76 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Test Results (ASTM C117 & C136)Material Description Atterberg Limits Coefficients Classification Test Remarks Sample Date:Location: TP-08 Sample Number: A-31504 Depth: 5.0 - 8.0 ft Client: Project: Project No: Figure Sieve Size or Diam. (mm.) Finer (%) Spec.* (%) Out of Spec. (%) Pct. of Fines Clayey GRAVEL with Sand 6" 4" 3" 2" 1.5" 1" 3/4" 1/2" 3/8" #4 #10 #20 #40 #60 #80 #100 #200 100.0 93.0 86.4 78.9 73.6 66.1 58.9 51.5 47.8 39.4 33.8 29.2 24.9 20.9 18.0 16.4 12.7 85.8 74.1 63.2 53.0 45.8 41.5 32.2 24 35 11 89.1211 71.1930 19.9992 11.4013 0.9793 0.1202 GC A-2-6(0) Report No. A-31504-206 Report Date: 4-23-2025 F.M.=5.62 Gallatin Valley Land Trust GVLT Bike Park Bozeman, Montana B25-012-001 PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= *(no specification provided) 15 Tested By: BC Checked By: LIQUID AND PLASTIC LIMITS TEST REPORT PLASTICITY INDEX0 10 20 30 40 50 60 LIQUID LIMIT 0 10 20 30 40 50 60 70 80 90 100 110 CL-ML C L o r O L C H o r O H ML or OL MH or OH Dashed line indicates the approximate upper limit boundary for natural soils 47 WATER CONTENT38 38.4 38.8 39.2 39.6 40 40.4 40.8 41.2 41.6 42 NUMBER OF BLOWS 5 6 7 8 9 10 20 25 30 40 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Project No. Client: Remarks: Project: Location: TP-03 Sample Number: A-31495 Depth: 5.0 - 6.0 ft Figure Lean CLAY 39 19 20 98.0 93.8 CL B25-012-001 Gallatin Valley Land Trust 16 Report No. A-31495-207 Report Date: 4-23-2025GVLT Bike Park Bozeman, Montana Tested By: BS Checked By: LIQUID AND PLASTIC LIMITS TEST REPORT PLASTICITY INDEX0 10 20 30 40 50 60 LIQUID LIMIT 0 10 20 30 40 50 60 70 80 90 100 110 CL-ML C L o r O L C H o r O H ML or OL MH or OH Dashed line indicates the approximate upper limit boundary for natural soils 47 WATER CONTENT31.6 31.8 32 32.2 32.4 32.6 32.8 33 33.2 33.4 33.6 NUMBER OF BLOWS 5 6 7 8 9 10 20 25 30 40 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Project No. Client: Remarks: Project: Location: TP-05 Sample Number: A-31498 Depth: 2.0 ft Figure Sandy Lean CLAY 33 18 15 80.4 58.4 CL B25-012-001 Gallatin Valley Land Trust 17 Report No. A-31498-207 Report Date: 4-12-2025GVLT Bike Park Bozeman, Montana Tested By: BC Checked By: LIQUID AND PLASTIC LIMITS TEST REPORT PLASTICITY INDEX0 10 20 30 40 50 60 LIQUID LIMIT 0 10 20 30 40 50 60 70 80 90 100 110 CL-ML C L o r O L C H o r O H ML or OL MH or OH Dashed line indicates the approximate upper limit boundary for natural soils 47 WATER CONTENT37.5 37.7 37.9 38.1 38.3 38.5 38.7 38.9 39.1 39.3 39.5 NUMBER OF BLOWS 5 6 7 8 9 10 20 25 30 40 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Project No. Client: Remarks: Project: Location: TP-07 Sample Number: A-31501 Depth: 2.0 ft Figure Sandy Lean CLAY 38 21 17 76.0 59.4 CL B25-012-001 Gallatin Valley Land Trust 18 Report No. A-31501-207 Report Date: 4-23-2025GVLT Bike Park Bozeman, Montana Tested By: BS Checked By: LIQUID AND PLASTIC LIMITS TEST REPORT PLASTICITY INDEX0 10 20 30 40 50 60 LIQUID LIMIT 0 10 20 30 40 50 60 70 80 90 100 110 CL-ML C L o r O L C H o r O H ML or OL MH or OH Dashed line indicates the approximate upper limit boundary for natural soils 47 WATER CONTENT31 32 33 34 35 36 37 38 39 40 41 NUMBER OF BLOWS 5 6 7 8 9 10 20 25 30 40 MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Project No. Client: Remarks: Project: Location: TP-08 Sample Number: A-31504 Depth: 5.0 - 8.0 ft Figure Clayey GRAVEL with Sand 35 24 11 24.9 12.7 GC B25-012-001 Gallatin Valley Land Trust 19 Report No. A-31504-207 Report Date: 4-23-2025GVLT Bike Park Bozeman, Montana Tested By: BS Checked By: Moisture-Density Test Report for Curve No. A-31498 Dry density, pcf95 100 105 110 115 120 Water content, % 10 12.5 15 17.5 20 22.5 25 15.8%, 110.3 pcf ZAV for Sp.G. = 2.70 Test specification:ASTM D 698-12 Method A Standard 2.0 ft CL A-6(6) Not Measured 2.7 33 15 1.1 58.4 Sandy Lean CLAY B25-012-001 Gallatin Valley Land Trust Report No. A-31498-204 Report Date: 4-12-20254-10-2025 20 Elev/ Classification Nat.Sp.G. LL PI % > % < Depth USCS AASHTO Moist. #4 No.200 TEST RESULTS MATERIAL DESCRIPTION Project No. Client:Remarks: Project: Date: Location: TP-05 Sample Number: A-31498 Figure Maximum dry density = 110.3 pcf Optimum moisture = 15.8 % GVLT Bike Park Bozeman, Montana Tested By: CRN Checked By: BEARING RATIO TEST REPORT ASTM D1883-14 Project No: B25-012-001 Project:GVLT Bike Park Location: TP-05 Sample Number: A-31498 Depth: 2.0 ft Date: 4-1-2025 Sandy Lean CLAY Test Description/Remarks: ASTM D698 with 6-inch mold 96-hour soak prior to testing Report No. A-31498-210 Report Date: 5-9-2025 Figure 21 110.3 15.8 33 15CL Material Description USCS Max. Dens. (pcf) Optimum Moisture (%) LL PI Molded Density (pcf) Percent of Max. Dens. Moisture (%) Soaked Density (pcf) Percent of Max. Dens. Moisture (%) CBR (%) 0.10 in. 0.20 in. Linearity Correction (in.) Surcharge (lbs.) Max. Swell (%) 1 98.2 89 16.3 97.7 88.6 20.1 3.1 2.8 0.000 10 0.4 2 103.2 93.6 16.3 102.8 93.2 18.2 3.2 4.0 0.000 10 0.3 3 111.6 101.2 16.4 111.5 101.1 16.0 4.8 4.5 0.000 10 0.1Penetration Resistance (psi)0 40 80 120 160 200 Penetration Depth (in.) 0 0.1 0.2 0.3 0.4 0.5 Swell (%)0 0.1 0.2 0.3 0.4 0.5 Elapsed Time (hrs) 0 24 48 72 96CBR (%)2 3 4 5 6 Molded Density (pcf) 93 98 103 108 113 118 10 blows 20 blows 64 blows CBR at 90% Max. Density = 3.1% for 0.10 in. Penetration General Project Information Project Number: B25-012-001 Project Title: GVLT Bike Park Project Description: Climatic Data Source (MERRA) Latitude, Degree: 45.71871 Longitude, Degree: -111.03372 Climatic Data Lowest Yearly Air Temperature, ºC: -31.47 Low Air Temp Standard Deviation, ºC: 5.13 Yearly Degree-Days > 10 Deg. ºC: 1662.04 High Air Temperature of high 7 days: 28.96 Standard Dev. of the high 7 days: 1.98 Low Pavement Temperature 50%*: -30.50 Low Pavement Temperature 98%*: -39.30 High Avg Pavement Temperature of 7 Days 50%: 50.94 High Avg Pavement Temperature of 7 Days 98%: 55.10 Target Rut Depth Target Rut Depth (mm): 16.5 Temperature Adjustments Depth of Layer, mm: 0 Base HT PG: 52 Traffic Adjustments Traffic loading Cumulative ESAL for the Design Period, Millions: 0.05 Traffic Speed (Fast: >70 km/h, Slow: 20-70 km/h, Standing: < 20 km/h): Standing Performance Grade AASHTO M320-10 Performance-Graded Asphalt Binder PG Temperature High Low Performance Grade Temperature at 50% Reliability*35.8 -23.8 Performance Grade Temperature at 98% Reliability*39.8 -32.6 Adjustment for Traffic (AASHTO M323-13)2.8 Adjustment for Depth 0.0 0.0 Adjusted Performance Grade Temperature 42.6 -32.6 Selected PG Grade 52 -34 PG Grade M323, PG 52-34 5/12/25, 7:21 PM LTPPBind Online about:blank 1/2 TD&H Engineering Consultants Great Falls, Kalispell, Bozeman, MT Spokane, WA; Lewiston, ID, Watford City, ND TD&H Engineering Consultants Great Falls, Kalispell, Bozeman, MT Spokane, WA; Lewiston, ID, Watford City, ND APPENDIX G ADDITIONAL TEST PIT DATA BIKEFILL BIKE PARK 22147.01 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears relatively firm, dark brown, moist, abundant organics Sandy Lean CLAY, appears relatively stiff, brown, moist -suspected fill material Clayey GRAVEL with Sand, appears relatively dense, brown, moist -suspected native gravel deposit Bottom of Test Pit 2.8 9.0 10.0 Ground water not encoun- tered LEGEND LOG OF TEST PIT Pond #1Atterberg Limits Field Moisture content GVLT Bike Fill: Stormwater Test Pits- Visual Classifications Bozeman, Montana Groundwater Level Grab/composite sample Logged by:Colton Shaff EI Excavated by:Integrated Trail Labs CAT 306 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 6, 2026 B25-012 Figure No.1 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:Not Measuered DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears relatively firm, dark brown, moist, abundant organics Clayey GRAVEL with Sand, appears medium dense, brown, moist, 18" minus -suspected fill material, gravel appears inconsistent and intermixed with clay deposits Sandy Lean CLAY, appears relatively stiff, brown, moist, -suspected fill material Clayey GRAVEL with Sand, appears relatively dense, brown, moist -suspected native gravel deposit Bottom of Test Pit 1.6 3.9 8.0 9.7 Ground water not encoun- tered LEGEND LOG OF TEST PIT Pond #2Atterberg Limits Field Moisture content GVLT Bike Fill: Stormwater Test Pits- Visual Classifications Bozeman, Montana Groundwater Level Grab/composite sample Logged by:Colton Shaff EI Excavated by:Integrated Trail Labs CAT 306 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 6, 2026 B25-012 Figure No.2 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:Not Measuered DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears relatively firm, dark brown, moist, abundant organics Sandy Lean CLAY, appears relatively firm, brown, moist -suspected fill material Clayey GRAVEL with Sand, appears medium dense, brown, moist, 18" minus -suspected fill material, gravel appears inconsistent and intermixed with clay deposits. Sandy Lean CLAY, appears relatively stiff, brown, moist -suspected fill material Bottom of Test Pit 0.5 5.2 8.3 11.0 Ground water not encoun- tered LEGEND LOG OF TEST PIT Pond #3Atterberg Limits Field Moisture content GVLT Bike Fill: Stormwater Test Pits- Visual Classifications Bozeman, Montana Groundwater Level Grab/composite sample Logged by:Colton Shaff EI Excavated by:Integrated Trail Labs CAT 306 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 6, 2026 B25-012 Figure No.3 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:Not Measuered DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears relatively firm, dark brown, moist, abundant organics Sandy Lean CLAY, appears relatively stiff, brown, moist -suspected fill material, 18" minus boulder inclusions observed Sandy Lean CLAY with Gravel, appears relatively stiff, brown, moist -suspected fill material Bottom of Test Pit 5.3 11.5 12.0 Ground water not encoun- tered LEGEND LOG OF TEST PIT Pond #4Atterberg Limits Field Moisture content GVLT Bike Fill: Stormwater Test Pits- Visual Classifications Bozeman, Montana Groundwater Level Grab/composite sample Logged by:Colton Shaff EI Excavated by:Integrated Trail Labs CAT 306 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 6, 2026 B25-012 Figure No.4 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:Not Measuered DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears relatively firm, dark brown, moist, abundant organics Sandy Lean CLAY, appears relatively firm, brown, moist -suspected fill material Clayey GRAVEL with Sand, appears medium dense, brown, moist, 18" minus -suspected fill material, gravel appears inconsistent and intermixed with clay deposits Sandy Lean CLAY with Gravel, appears relatively stiff, brown, moist -suspected fill material Bottom of Test Pit 0.5 5.3 9.2 11.2 Ground water not encoun- tered LEGEND LOG OF TEST PIT Pond #5Atterberg Limits Field Moisture content GVLT Bike Fill: Stormwater Test Pits- Visual Classifications Bozeman, Montana Groundwater Level Grab/composite sample Logged by:Colton Shaff EI Excavated by:Integrated Trail Labs CAT 306 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 6, 2026 B25-012 Figure No.5 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:Not Measuered DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears relatively firm, dark brown, moist, abundant organics Sandy Lean CLAY, appears relatively firm, brown, moist -suspected fill material Clayey GRAVEL with Sand, appears medium dense, brown, moist, 18" minus -suspected fill material, gravel appears inconsistent and intermixed with clay deposits. Sandy Lean CLAY, appears relatively stiff, brown, moist -suspected fill material Clayey GRAVEL with Sand, appears relatively dense, brown, moist -suspected native gravel deposit Bottom of Test Pit 0.5 5.0 7.2 10.5 10.8 Ground water not encoun- tered LEGEND LOG OF TEST PIT Pond #6Atterberg Limits Field Moisture content GVLT Bike Fill: Stormwater Test Pits- Visual Classifications Bozeman, Montana Groundwater Level Grab/composite sample Logged by:Colton Shaff EI Excavated by:Integrated Trail Labs CAT 306 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 6, 2026 B25-012 Figure No.6 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:Not Measuered DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears relatively firm, dark brown, moist, abundant organics Sandy Lean CLAY, appears relatively stiff, brown, moist -suspected fill material Clayey GRAVEL with Sand, appears relatively dense, brown, moist, 8" minus -suspected native gravel deposit Bottom of Test Pit 4.2 9.3 11.0 Ground water not encoun- tered LEGEND LOG OF TEST PIT Dry Well - Large PTAtterberg Limits Field Moisture content GVLT Bike Fill: Stormwater Test Pits- Visual Classifications Bozeman, Montana Groundwater Level Grab/composite sample Logged by:Colton Shaff EI Excavated by:Integrated Trail Labs CAT 306 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 6, 2026 B25-012 Figure No.7 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:Not Measuered DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 0 2 4 6 8 10 12 14 TOPSOIL: Lean CLAY, appears relatively firm, dark brown, moist, abundant organics Clayey GRAVEL with Sand, appears relatively dense, brown, moist -suspected fill material, gravel appears inconsitent and intermixed with clay deposits Sandy Lean CLAY with Gravel, appears relatively stiff, brown, moist Clayey GRAVEL with Sand, appears relatively dense, brown, moist, 18" minus -suspected native gravel deposit Bottom of Test Pit 4.3 5.8 9.9 10.8 Ground water not encoun- tered LEGEND LOG OF TEST PIT Dry Well - Small PTAtterberg Limits Field Moisture content GVLT Bike Fill: Stormwater Test Pits- Visual Classifications Bozeman, Montana Groundwater Level Grab/composite sample Logged by:Colton Shaff EI Excavated by:Integrated Trail Labs CAT 306 ExcavatorGNP = Granular and Nonplastic Note: The stratification lines represent approximate boundaries between soil types. Actual boundaries may be gradual or transitional. July 6, 2026 B25-012 Figure No.8 SheetGRAPHICLOGSOIL DESCRIPTION SURFACE:Native Grasses SURFACE ELEVATION:Not Measuered DEPTH (FT)GROUNDWATERSAMPLEDEPTH (FT)MOISTURE CONTENT 0 10 20 30 40 50 = MOISTURE CONTENT 1 of 1 APPENDIX H MCILHATTAN ROAD DRAINAGE REPORT BIKEFILL BIKE PARK 22147.01 DRAINAGE REPORT 22147.01 Bozeman, MT APRIL 2026 FOR MCILHATTAN ROAD ADJACENT TO BIKEFILL BIKE PARK DRAINAGE REPORT FOR MCILHATTAN ROAD CERTIFICATION I hereby state that this Final Drainage Report has been prepared by me or under my supervision and meets the standard of care and expertise which is usual and customary in this community of professional engineers. The analysis has been prepared utilizing procedures and practices specified by the City of Bozeman and within the standard accepted practices. Robert Egeberg, P.E. Date 4/17/2026 April 17, 2026 Project No. 22147.01 STORM DRAINAGE REPORT FOR MCILHATTAN ROAD BOZEMAN, MONTANA INTRODUCTION The project is in the City of Bozeman within Gallatin County, Montana. The purpose of this storm drainage report is to describe the drainage design associated with the improvements to McIlhattan Road. The road will be realigned and improved along the unpaved section that is just north of St. Andrews Drive to just south of Snowfill Dog Park. HYDROLOGY & HYDROGEOLOGY The minor design storm used is a 10-year storm per the City of Bozeman Design and Construction Standards (COBDCS), October 2024. Sub watersheds were delineated using a combination of Stream Stats and delineating basins based on topography. Within the Churn Creek watershed, Multi-Resource Land Characteristics and Web Soil Survey were used to determine the land use and curve number for the watershed. A time of concentration was determined from considering multiple flow paths and determining the shortest time of concentration to be conservative. The SWM SCS method was used to calculate expected flows within the Churn Creek watershed. Outside of the Churn Creek watershed, all watersheds were delineated using topography. Within these watersheds, impervious, previous, and gravel areas were determined to calculate the weighted runoff coefficients for each watershed. Runoff Coefficients Impervious 0.95 Pervious 0.20 Gravel 0.75 2 (04/16/26) DME/RPE A time of concentration was determined for each of these watersheds. The delineated watersheds contained relatively short flow lengths, a minimum time of concentration of five minutes was used. The Rational Method was used to calculate expected flows within each delineated watershed. EXISTING STORMWATER DRAINAGE CONDITIONS Existing drainage conditions for McIlhattan Road vary significantly throughout the length of the project. Stormwater drainage is split into six different watersheds. These watersheds can be seen in Appendix A. Along the existing alignment there are three low points where drainage is conveyed from the east side of the road to the west side of the road. Drainage then makes its way to three separate wetland areas that flow towards the East Gallatin River. Longitudinal slopes generally flow from south to north and north to south along the alignment with the ultimate low point at the culvert crossing with Churn Creek. The south half of the project area exhibits very steep slopes on either side of the roadway with some slopes being 1:1. Starting on the south end of the road the first culvert, 24-inches RCP, collects drainage from the north end of the Bridger Creek subdivision to approximately station 1+30 along the proposed alignment. The drainage along McIlhattan Road flows south at a slope of 2.5 percent. The culvert slopes east to west at 5.6 percent and releases into a wetland area that eventually flows into the East Gallatin River. This culvert has a maximum discharge of 27.62-cfs before it overtops. Therefore, with the minimal repaving this culvert will remain in place as it has capacity and is outside of the project limits for the scope of this project. The second culvert, 15-inches CMP, collects drainage from the north that flows down from the hill that begins at the City of Bozeman owned parking lot at 2143 Story Mill Road. It conveys the wetland that is at approximately 2+90 along the proposed alignment. The culvert slopes east to west at 13 percent, and releases into the same wetland area as the first existing culvert before eventually flowing into the East Gallatin River. This culvert will be replaced with a 24-inch culvert to match the City of Bozeman minimum culvert size. The third culvert, 24-inches CMP, collects drainage from the east city owned property. Longitudinally drainage is conveyed from 2+50 to 7+30 at a slope of 3.56 percent that goes south to north. Drainage is also conveyed from 8+00 to 7+30 at a slope of 2.8 percent that flows north to south. This culvert slopes east to west at a slope of 9.6 percent and releases into a wetland area that eventually flows into the East Gallatin River. This culvert will be demoed within the scope of this project. The fourth culvert, 30-inches CMP, collects drainage from Churn Creek. Longitudinally drainage is conveyed from 8+00 to 13+85 at a slope of 5.0 percent that flows south to north. Drainage is also conveyed from the end station to 13+85 at an approximate slope of 7.1 percent. The culvert slopes east to west at a slope of 4.3 percent and eventually 3 (04/16/26) DME/RPE flows into the East Gallatin River. This culvert will be removed and replaced with a 88”x54” concrete arch culvert. Drainage that falls on the west crown of existing McIlhattan Road flows directly west into the wetlands and eventually to the East Gallatin River. PROPOSED STORMWATER DRAINAGE SYSTEM The proposed drainage system associated with the new road improvements will consist of new asphalt curb, inlets, culverts, and a v-ditch. The proposed drainage has been split into eleven drainage basins. Refer to Appendix A, to see the on-site proposed watersheds. The captured flow will be conveyed to the existing wetland basins to perpetuate historical drainage. In captured areas, the water quality volume will be stored and released at pre-development flowrates. The proposed road alignment shifted about 12-feet east of the original roadway alignment to create a shoulder that will be less susceptible to sloughing off after large storm events, while trying to maintain similar longitudinal slopes to perpetuate the original design. There are two localized low points within the centerline alignment of the project. The low points of the proposed alignment were generally sloped to match existing conditions and perpetuate historical flow patterns throughout the site. At these low points water to the west of the crown of McIlhattan Road will be captured by an asphalt curb before being transported into an inlet and out a storm drain pipe. The proposed storm system has been designed to covey the runoff from the 10-year storm event. Detention systems have been designed to treat the water quality volume as it exceeded the water quantity volume for the 10-year storm in each proposed basin. The 100-year storm was also evaluated for each drainage basin, outfall structures have been designed to convey the pre-development flowrate for the major storm event. Culvert Calculations The first culvert occurs at station 3+21.18 and is replacing the existing 15-inch CMP that collects drainage from the east that flows down from the hill that begins at the City of Bozeman owned parking lot at 2143 Story Mill Road. This flow area is defined by proposed basin two. The peak flow for a five-minute time of concentration in this area is 1.65-cfs. Flow is collected by a 24-inch circular inlet. The depth at the inlet will be 0.27-feet during the major storm, runoff will not leave the v-ditch in this event. The culvert was sized to allow no flow to overtop the roadway during the minor storm and to minimize overtopping to six-inches at the street crown during the major storm. There are no dwellings that are at risk in the event of overtopping from this culvert. Within the Churn Creek watershed, Multi-Resource Land Characteristics and Web Soil Survey were used to determine the land use and curve number for the watershed. A time of concentration was determined from considering multiple flow paths and determining the shortest time of concentration to be conservative. The SWM SCS method was used to calculate expected flows within the Churn Creek watershed using AutoDesk Storm and Sanitary Sewer Analysis 2022. The following table shows the 4 (04/16/26) DME/RPE statistical data from the Sanitary Sewer Analysis Model for the minor and major storm event. Storm Event Area (acres) CN Peak Rate Factor Total Precipitation (inches) Total Runoff (inches) Peak Runoff (cfs) Time of Concentration (minutes) 10-year 704 67 484 1.90 0.14 24.19 58 100-year 704 67 484 2.80 0.49 142.11 58 The peak runoff for the minor storm was used for the design flow of the culvert. FHWA HY-8 was used to analyze the crossing. The culvert was sized to allow no flow to overtop the roadway during the minor storm and to minimize overtopping at the street crown during the major storm to less than six-inches and have a Hw/D ratio of less than or equal to 1.5 in the minor and major storm events. In the case of a major storm event flow begins to overtop the culvert at a total discharge of 108.09-cfs. Headwater elevation will reach a maximum elevation of 4689.55, the low point crown elevation of the road is 4689.24. There are no dwellings that are at risk in the event of overtopping from this culvert. The culvert has been designed to be countersunk one foot into the natural stream as to be aligned with USACE regulations. Countersinking the culvert by one-foot allows the natural streambed to be maintained. See Appendix C for HY-8 calculations. Required Storage Volume Calculations – 10-Year Storm There are three proposed underground storage areas proposed within the design of the project. The underground storage has been designed to capture the runoff volume from the minor storm for multiple proposed watershed basins. Each underground storage area has been designed to release runoff events at both the pre-development flowrate for the minor and major storm event. ADS Chamber System A Proposed basins three and ten are detained by the proposed ADS A chamber system for the 10-year storm event. The two basins have a combined total area of 0.93-acres and have a runoff coefficient of 0.43, a required water quantity storage of 204-ft3, and a water quality storage of 533-ft3. The ADS chamber system has a total volume of 697-ft3, making the storm system adequate to meet the storage requirements. The pre-development peak flow of 0.884-cfs was used as a discharge rate when sizing the chamber system. V = (C x i x A x t x 60)-(d x t x 60) Where: C=0.43; i=3.87; A=0.93 acres; t=5 min; d=0.884-cfs 5 (04/16/26) DME/RPE Water Quantity Volume=204-ft3 WQV = (((P)(Rv)(A))/12) x 43,560 Where: P=0.5, Rv=0.32; A=0.93-acres Required Volume=533-ft3 ADS Chamber System B Proposed basin four is detained by the proposed ADS B chamber system for the 10-year storm event. The basin has a total area of 1.11-acres and have a runoff coefficient 0.40, a required water quantity storage of 201-ft3, and a water quality storage of 551-ft3. The ADS chamber system has a total volume of 784-ft3, making the storm system adequate to meet the storage requirements. The pre-development peak flow of 1.033-cfs was used as a discharge rate when sizing the chamber system. V = (C x i x A x t x 60)-(d x t x 60) Where: C=0.40; i=3.87; A=1.11 acres; t=5 min; d=1.033-cfs Water Quantity Volume=201-ft3 WQV = (((P)(Rv)(A))/12) x 43,560 Where: P=0.5, Rv=0.27; A=1.11-acres Required Volume=551-ft3 ADS Chamber System C Proposed basin six is detained by the proposed ADS C chamber system for the 10-year storm event. The basin has a total area of 0.88-acres and have a runoff coefficient of 0.49, a required water quantity storage of 391-ft3, and a water quality storage of 602-ft3. The ADS chamber system has a total volume of 755-ft3, making the storm system adequate to meet the storage requirements. The pre-development peak flow 0.579-cfs was used as a discharge rate when sizing the chamber system. V = (C x i x A x t x 60)-(d x t x 60) Where: C=0.49; i=2.83; A=0.88 acres; t=10 min; d=0.579-cfs Water Quantity Volume=391-ft3 6 (04/16/26) DME/RPE WQV = (((P)(Rv)(A))/12) x 43,560 Where: P=0.5, Rv=0.38; A=0.88-acres Required Volume=609-ft3 Proposed Basins one, five, seven, eight, nine, eleven, and twelve flow offsite and are not captured by proposed storm infrastructure. These basins continue their existing drainage pattern and flow towards existing drainage facilities. The amount of impervious areas has not increased significantly enough from the original gravel road discharge to effect the existing storm infrastructure with the addition of the detention chamber systems the overall peak discharge is reduced by at least 0.26 cfs. Water Quality The City of Bozeman has a requirement to capture or reuse the runoff generated from the first 0.5-inches of rainfall from a 24-hour storm. This requirement is met by detaining runoff on-site in the three below grade chamber systems. In addition to the storage provided in the detention facilities, sumps will be installed in the storm drain inlets prior to outflow, providing treatment before water infiltrates into the ground. Stormwater detention systems need to be maintained, per the recommendations in the Operations and Maintenance Manual, see Appendix D. Calculations: WQV = ((P x Rv x A) / 12) x 43,560 Where: WQV= Water Quality Volume P=Water Quality Rainfall Depth, inches (0.5-inches) Rv=The Unitless Runoff Coefficient, Rv=0.5+0.9(I) I=the percent impervious cover draining to the facility A=total site area draining to the structure ADS A WQV=533-ft3 Discharge=0.884-cfs Drawdown Time=533 cf / 3,182.4 cf/hr = 0.17-hours ADS B WQV=551-ft3 Discharge=1.033 cfs Drawdown Time=551 cf / 3,718.8 cf/hr = 0.15-hours 7 (04/16/26) DME/RPE ADS C WQV=609-ft3 Discharge=0.579-cfs Drawdown Time=609 cf / 2,084.4 cf/hr = 0.29-hours Gutter Flow and Inlet Calculations – 10-Year Storm The inlet locations were designed to limit the maximum curb flow as described in the COBDCS in relation to the street classification. Due to the classification of this street being a Local Collector Street, no curb overtopping is allowed, and flow spread must leave at least one, eleven foot lane free of water during the minor storm. The Rational Method was used to determine the flow to each inlet. A minimum five-minute time of concentration was estimated for each of the subbasin and inlet calculations. Inlets were sized to handle the peak flow resulting from the minor storm event. Flow intercepted by drainage inlets were determined using Federal Highway Administration (FHWA) Hydraulic Toolbox Software Version 5.3.0. All proposed inlet locations in sag conditions were sized assuming a 50 percent clogging factor, while inlets on-grade assumed a 25 percent clogging factor. For further information on inlet capacity calculations, see Appendix C. Storm Piping Design – 10-Year Storm Storm drain pipes exiting inlets were sized to handle peak flow resulting from the minor storm. Storm drain pipes exiting Storm Drain Manholes, that outflow east, were sized to handle peak flow resulting from the major storm. All storm drain pipes were designed with a minimum slope to maintain a full-flow velocity of at least 2.5-feet per second while limiting the full flow velocity to a maximum of 12-feet per second. The Federal Highway Administration (FHWA) Hydraulic Toolbox Software Version 5.3.0 was used to determine pipe sizing for the full flow capacity of the pipes. For further information on storm drain capacity calculations, see Appendix C. OUTLET STRUCTURES Each ADS chamber system has an outlet structure. The outlet structures have been designed to the COB Standard Drawing No. 02720-12 and have an orifice that releases the minor storm and major storm to the 5-min peak flow for the pre-development peak flow rate. Each orifice was defined with the following equation: h = Head Water Depth ft Cd = Discharge Coefficient 8 (04/16/26) DME/RPE A = Open Area ft2 g = Gravity ft/s2 Q = C x A x (2 x g x h)0.5 See Appendix C for orifice calculations for SDMH A, SDMH B, and SDMH C. CONCLUSION All runoff from the new hardscape and landscape areas being constructed will be captured and detained on-site to the greatest extent possible. There are three below grade detention ponds that will be constructed to capture the minor storm event and release outflow to the pre-development minor and major storm peak flows. In addition to the three outlet structures, two culverts will be constructed within the scope of the project. Each culvert has been designed to allow no overtopping of the road during the minor storm event and restrict overtopping to less than six-inches above the crown of the road during the major storm event. APPENDICES Appendix A – Stormwater Basins Appendix B – Hydrology Calculations Appendix C – Hydraulic Calculations Appendix D – O&M Plan Appendix E – TD&H Geotechnical Report