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HomeMy WebLinkAbout029 Stormwater ManagementGran Cielo Subdivision Phase 3 Preliminary Plat Application 29 - Stormwater Management Please see the responses below to the items requested in Section 38.220.060.A.10 in the Bozeman Municipal Code. Stormwater management. A stormwater management plan meeting the requirements of section 40.04.700 and the city's adopted stormwater master plan. To control the quality, volume and rate of stormwater runoff to storm drains and prevent the deterioration of water quality, all new developments and redevelopment projects will be required to submit a stormwater management plan or a comprehensive drainage plan to the city engineering department for approval. The stormwater master plan and city Design Standards establish standards and guidelines for implementing BMPs and stormwater management is incorporated by reference and made part of this article. 1. A comprehensive drainage plan is required for all developments larger than five acres. 2. A stormwater management plan is required for all developments equal to or less than five acres and are designated as a sketch plan or larger in accordance to chapter 38, article 19, or are within 50 feet of a watercourse. 3. Redevelopment projects will be required to submit stormwater management plans or operation and maintenance plans if they meet the criteria found in the stormwater master plan, Design Standards, chapter 38, article 19, or this article. 4. Stormwater management plans and comprehensive drainage plans shall: a. Prevent any off-site direct discharge of untreated stormwater and non- stormwater from development or redevelopment improvements. b. Minimize increased post-development discharge rates or volumes. c. Provide for the removal of total suspended solids or other constituents so as to meet the median concentration of the state general permit for MS4s generated from development or redevelopment runoff prior to any off-site discharge. d. Continue BMPs for appropriate periods of time. e. Protect groundwater from development runoff infiltration. f. Implement accepted BMPs to minimize impact of a development on existing offsite infrastructure and stormwater facilities. g. Address other stormwater issues identified by the city. h. Comply with section II of the city Design Standards, and chapter 38, article 23. 5. All drainage system reports, peak flow rates and runoff volume calculations, safety requirements, and grading plans shall be certified by a licensed professional authorized by the state to perform such functions. 6. The city reserves the right to amend, modify and/or add requirements to the stormwater master plan. Please see the stormwater report included in this section, which addresses the above requirements. STORMWATER MANAGEMENT DESIGN REPORT FOR: Gran Cielo Subdivision, Phase 3 Bozeman, MT Prepared By: WWC/Madison Engineering 895 Technology Drive, Suite 203 Bozeman, MT 59718 (406) 586-0262 January 2026 STORMWATER MANAGEMENT DESIGN REPORT FOR: Gran Cielo Subdivision, Phase 3 Bozeman, MT WWC/Madison Engineering 895 Technology Blvd Ste 203 Bozeman, MT 59718 (406) 586-0262 January 2026 Page 1 of 11 Table of Contents 1. Introduction ............................................................................................................................. 2 2. Hydrology and Hydrogeology ................................................................................................ 3 3. Existing Conditions and Drainage Conditions ........................................................................ 3 3.1 Pre-development Runoff Conditions .............................................................................. 4 4. Proposed Stormwater Drainage System .................................................................................. 5 4.1 Post-Development Runoff Calculations ......................................................................... 6 4.2 Modifications to Existing Stormwater Facilities ............................................................ 7 4.3 Groundwater Considerations .......................................................................................... 8 4.4 Water Quality Treatment ................................................................................................ 9 4.5 Pre-Development vs. Post-Development Comparison ................................................... 9 5. Evaluation of Major Storm Flood Risks ............................................................................... 10 6. Operation, Inspection, and Maintenance Considerations ..................................................... 10 7. References ............................................................................................................................. 10 8. Conclusion ............................................................................................................................ 10 9. Appendices ............................................................................................................................ 10 Page 2 of 11 895 Technology Boulevard, Suite 203, Bozeman, MT 59718 | 406.586.0262 Gran Cielo Subdivision, Phase 3 Stormwater Design Report 1. Introduction This design report overviews the proposed stormwater system for the proposed Gran Cielo Subdivision, Phase 3, located South of Apex Drive, West of South 27th Avenue, North of Bennett Boulevard, and East of South 29th Avenue. The subdivision will include the extension of utilities, and roadways, for the proposed residential lots. The legal description of the property is Lots 1-4 and Open Space C, Block 14, Gran Cielo Subdivison, Phase 2, S23, T02 S R05 E. The property is currently undeveloped and generally grass covered. The intended development of the subject property is that of a residential neighborhood consisting of forty-four (44) lots; forty (40) single household lots, one (1) multi-family household lot, two (2) townhome lots, and one (1) lots for stormwater management. Appendix C of this report shows the overall layout for the subdivision. The property naturally drains from south to north with no natural waterways existing on the lot. Adjacent to the northeast and east of the lot exists a lateral of the Middle Creek Ditch. A short section of this ditch was piped at the time South 27th. Avenue was installed in a previous phase within Gran Cielo Subdivision. A small section of the piped ditch lateral exists under the eastern edge of the proposed development. The lateral of the Middle Creek Ditch will not be affected by this development nor will any stormwater run-off be directed to the ditch. Due to the close proximity of the development, the organization that maintains the ditch, Middle Creek Ditch Company, was notified per BMC 38.360.280.B on October 31st, 2025. The response period expired on December 15th and no response from the company was received. Additionally, the subject property is not within any floodways as identified on the FEMA website. Drainage exhibits have been included in Appendix B of this report to illustrate the existing and proposed drainage conditions of the site and surrounding infrastructure. Stormwater runoff will be managed with the use of both existing and proposed curb and gutter, piping, rain gardens, and detention ponds. All proposed systems will meet both City of Bozeman And Montana DEQ requirements. This development is the third phase of the Gran Cielo Subdivision and thus, the surrounding roads and developments have been assessed in previous stormwater reports and under previous stormwater guidelines, which will be frequently referenced in this report. These reports have been included in Appendix H. Page 3 of 11 2. Hydrology and Hydrogeology The hydraulic design for this development is based on the standards outlined in Section 6 of the City of Bozeman Design and Construction Standards (2024). Run off was calculated utilizing the NRCS (SCS) Curve Number Method, selected due to the size of the development being greater than 5 acres, per Section 6.6.3 of the Design and Construction Standards. Other run-off calculation methods were considered, such as the Rational Method, but were deemed to be less applicable to this project than the NRCS Method. The stormwater analysis for this project considers the 10-year, 24-hour (minor) storm event and the 100-year, 24-hour (major) storm event, and the water quality design event (0.5- inch rainfall depth). All values for the major and minor storm events were determined using the 24-hour values defined in Table 6.5.2 of the City of Bozeman Design and Construction Standards. A geotechnical investigation was conducted in 2007 by HKM for the Gran Cielo Subdivision which included the Phase 3 area. More recently, Allied Engineering Services, Inc. (AESI) has dug several test pits on the nearby and adjacent properties and provided a geotechnical analysis of their own regarding the phase 3 area (previously phase 4). The geotechnical report from AESI has updated several recommendations of the 2007 HKM report and is provided as an addendum to said report. The HKM investigation found that the soil profiles of the development site were generally characterized by topsoil from 0.6- 1.4 feet deep below ground surface, lean clay deposits ranging from 1.6-3.8 feet deep, and poorly graded gravel with sand and cobbles from then on. A few areas were observed to contain a transitional zone of clayey gravel between the lean clay and poorly graded gravel with sand and cobbles. The 2007 HKM report and 2023 AESI reports are included in Appendix H.1 and Appendix H.2, respectively, of this report. During the 2007 HKM investigation of the site, the seasonal high groundwater was observed to range from 1-3 feet below ground surface. In the 2023 AESI report, it is stated that groundwater table appears to have lowered to 3-8 feet in the vicinity of the subject property (Appendix H.2 AESI, pg. 6, Groundwater Conditions) due to the development of the Gran Cielo Subdivision. AESI states that groundwater was observed in 2022 to be at a depth of 4.5-5.0 feet during an investigation on the Bennett property to the southeast of the subject property (Appendix H.2 AESI, pg. 3, Summary of Site Conditions, paragraph 3). Hydraulic soil groups present on the subject property were identified the NRCS Soil Survey website. The property was identified to be 98.6% Hydraulic Soil Group B and 1.4% Hydraulic Soil Group C. A map showing the hydraulic soil group areas that comprise the subject property is included in Appendix A of this report. 3. Existing Conditions and Drainage Conditions The subject property is currently undeveloped but contains existing stormwater infrastructure constructed during the development of the Gran Cielo Subdivision, Phase 2. The stormwater pond located at the northwest corner of the site receives runoff from the subject property itself, along with runoff from Apex Drive, South 27th Avenue, and South 29th Avenue. Additionally, the existing pond was designed to receive overflow from the detention pond just south of Bennett Boulevard, of which receives stormwater runoff from Page 4 of 11 Phase 2 of the Gran Cielo Subdivision. This volume is stated as 9,281 cf in the stormwater report for Gran Cielo Subdivision Phase 2 (Appendix H.3 and H.4) and was factored into the required volume of the upgraded detention pond for Phase 3. The detention pond was designed with an emergency overflow weir, north of Apex Drive, as the designated outfall location. This detention pond will be redesigned to meet the updated stormwater requirements of the City of Bozeman. Specific improvements are discussed later in this report. The subject property is entirely bounded by local streets equipped with curb and gutter infrastructure, effectively preventing offsite stormwater contributions from adjacent parcels. As a result, all stormwater generated onsite remains contained within the property limits and conveys naturally to the existing stormwater pond. For pre-development conditions, the entire site is classified as a single drainage basin, designated “Basin A1,” as depicted in the Pre-Development Drainage Area Map provided in Appendix B of this report. Due to the need to re-design the existing stormwater pond to make its configuration fit within the proposed design for the new development, the stormwater runoff from the contributing roads; Apex Drive, South 29th Avenue, and a portion of South 27th Avenue were analyzed in the pre-development runoff conditions for the subject property. The contributing basin for the subject property is identified as “Basin A1” and the contributing roads as “Basin S1.” A detailed analysis of each contributing basin can be found in Appendix D.1. 3.1 Pre-development Runoff Conditions Pre-development conditions of the subject property were analyzed using the NRCS (SCS) hydrograph method utilizing HydroCAD. The NRCS method was selected due to the subject property being larger than 5 acres as recommended in Section 6.6.3 of the City of Bozeman Design and Construction Standards. Table 6.6.2 of the previously mentioned Design and Construction Standards lists Curve Numbers to be used based on the surface conditions of the site and the hydraulic soil group from the NRCS Soil Survey website. As can be seen in the map of the Hydraulic Soil Groups provided in Appendix A, the majority of the site is within Hydraulic Soil Group B and a small remainder in Group C. A weighted curve number was calculated for the 100% pervious predevelopment site and the times of concentration were calculated using the methods outlined in the NRCS TR-55 Manual, assuming sheet flow lengths no longer than 150 feet. HydroCAD then used these defined parameters to generate a hydrograph and identified a pre-development peak flow rate and runoff volume. Input parameters, methodologies, supporting calculations, and the resulting pre-development hydrographs can be found in Appendix D.1 of this report. Below is a summary table of the pre-development peak flows and runoff volume calculated. Page 5 of 11 Table 1: Pre-development Runoff Conditions Drainage Area Total Area (Acres) 10-yr Predevelopment Peak Runoff Flow Rate and Volume 100-yr Predevelopment Peak Runoff Flow Rate and Volume Outfall A1 6.694 0.36 cfs 0.088 ac-ft 1.52 cfs 0.231 ac-ft Outfall A S1 2.458 1.89 cfs 0.0.102 ac-ft 3.66 cfs 0.192 ac-ft Outfall A 4. Proposed Stormwater Drainage System The proposed stormwater drainage system has been designed in accordance with the City of Bozeman Design and Construction Standards to limit the post-development runoff to be less than or equal to the pre-development flow rates at the identified outfall. As was the case with the pre-development conditions, runoff from the adjacent roadways were included in the post-development runoff analysis. Including this runoff was crucial to ensuring the updated detention pond and associated outfalls were designed with enough storage capacity and the outfall adequately limited runoff to pre-development levels. A detailed analysis of each contributing basin can be found in Appendix D.2 of this report. The proposed stormwater management system will utilize paved sheet flow, curb and gutters, and underground piping to convey runoff to a designated stormwater storage facility. The proposed facilities consist of a single detention pond, Apex Pond, a retention pond located in the S. 27th Avenue right-of-way, and a boulevard infiltrator to help intercept runoff early and reduce the runoff flow rate from Basin A2. See Appendix C.3 of this report for boulevard infiltrator example taken from the 2025 City of Bozeman Stormwater Facilities Report (Figure 27, Page 53). The proposed facilities will also provide water quality treatment by removing sediment within the stormwater discharge (first 0.5 inch of runoff per City of Bozeman Standards). As mentioned, there exists on the subject property a stormwater pond, referred to as Apex Pond in the provided Gran Cielo Phase 2 Subdivision stormwater design report by Madison Engineering, dated 01-27-21. The report and associated As-Built documents are available for reference in Appendix H.3 and H.4 respectively, of this report. This pond was designed according to the previous City of Bozeman Standards (10-yr 2-hr rainfall event). The current outfall is moderated by a weir with an invert elevation of 4,942.49 feet and overflow elevation of 4,943 feet; this outlet structure will be modified to account for the increase in contributing runoff flow rates and volumes to the pond. Updates to the pond and outfall are discussed in detail in this section of the report. The previous phases of development of Gran Cielo Subdivision did not fully build South 27th Avenue to a collector standard. With Phase 3 of the Gran Ceilo Subdivision, a partial upgrade of 27th Avenue is now required. However, the responsibility of fully developing Page 6 of 11 the East half of the roadway falls to the future developers of the adjacent property. In order to mitigate impacts caused by the increase in stormwater runoff from South 27th Avenue, a temporary storage pond was designed to fully retain and infiltrate the associated stormwater runoff volume. The contributing area is identified on the post-development drainage area map in Appendix C.1 as “Basin S2.” See Appendix C.2 for detail on this retention pond and other previously mentioned stormwater facilities. Calculations supporting the temporary facility’s design can be found in Appendix D.2. 4.1 Post-Development Runoff Calculations Post-development conditions of the subject property were analyzed using the NRCS (SCS) hydrograph method utilizing HydroCAD. Runoff calculations are based on the pervious and impervious conditions at full build-out of the subject property and were used to determine weighted curve numbers for each drainage basin. Curve Numbers were selected from Table 6.6.2 of the City of Bozeman Design and Construction Standards. Time of Concentration for each basin was determined using the methods outlined in the TR-55 manual, and assume sheet flow lengths no more than 150 feet in length. These parameters were then used to generate a hydraulic model of the subject property which provide hydrographs along with peak flow rates and runoff volumes. In order to help reduce the peak flows in the major storm events, a boulevard infiltrator is implemented in the hydraulic design. This boulevard infiltrator will intercept flow from Basin A2, which is a mostly impervious drainage basin comprised of multi-family units and large parking areas. See examples in Appendix C.3 of this report. The infiltrators are modeled as detention basins with an inlet and outlet orifice, are three feet deep with the first two feet containing gravel at 40% void space and the last foot as 100% void to allow for ponding, allowing for a storage volume of 1,200 cf. This volume is significantly larger than the water quality event (first 0.5 inch of rain) volume of 48 cf, meaning that any suspended solids in the stormwater runoff will have sufficient time to infiltrate or settle out before discharging. In the rare even that the infiltrator was to fill with stormwater, there is a curb cut outlet that would allow for water to run down the gutter of South 28th Avenue to the detention pond. Additionally, the infiltrator will be excavated down to native gravel to ensure adequate drainage. Draw-down time was evaluated for each of the stormwater retention/detention facilities proposed in this design report. These times were evaluated to ensure that stormwater is infiltrated within 72 hours was required in the City of Bozeman Design And Construction Standards Section 6.8.2.C. An infiltration rate of 4.0 inches per hour was used for native gravels as specified in Table 3, DEQ-8. This rate was multiplied by by the area of gravel at the bottom of each facility to determine the infiltration capacity in cubic-feet per hour. This rate was then applied to the required storage of volume of the 100-year, 24-hour storm events to determine the maximum drain-down times for each facility. Apex Pond Drain-Down Capacity = 4.0in/hr * (1ft/12in) * 7,360 sf = 2,453 cf/hr Apex Pond Req’d volume = 29,792 cf Drain-Down time = 29,792 cf / 2,453 cf/hr = 12.14 hrs (less than required 72 hours) Page 7 of 11 S. 27th Avenue Retention Pond Drain-Down Capacity = 4.0in/hr * (1ft/12in) * 600 sf = 339.5 cf/hr S. 27th Ave Pond Req’d volume = 2,831 cf Drain-Down time = 2,831 cf / 339.5 cf/hr = 8.34 hrs (less than required 72 hours) S. 28th Avenue Boulevard Infiltrator Drain-Down Capacity = 4.0in/hr * (1ft/12in) * 1018.5 sf = 200 cf/hr S. 28th Ave Infiltrator Req’d volume = 1,200 cf Drain-Down time = 1,200 cf / 200 cf/hr = 6.0 hrs (less than required 72 hours) The hydraulic model was used for evaluating the volumes for each basin, as well as to estimate peak flows for determining the adequacy of existing stormwater infrastructure. The subject property is surrounded on all sides by developed roadways, two of which have existing stormwater infrastructure. The 2021 stormwater design report for Gran Cielo Subdivision Phase 2 can be found in Appendix H.3 of this report. The previous infrastructure design sized all the stormwater pipes to convey the 25-year storm event without exceeding 75% of the pipes capacity per City of Bozeman Standards. The proposed development of Gran Cielo Subdivision, Phase 3 is currently planned to discharge stormwater runoff to a short section of the existing infrastructure by which it will be conveyed to the resized stormwater pond (Apex pond). Currently, the existing infrastructure is unable to adequately convey the additional runoff from the addition of the post-development runoff. See below for detail modifications to the existing infrastructure to ensure proper conveyance of stormwater runoff. The hydraulic model was also used to determine the resizing of the existing detention pond, ensuring that the pre-development runoff rates are not exceeded by the post-development rates for the 2-year through 100-year storm events per City of Bozeman Design and Construction Standards section 6.8.2.G.a. Appendix D.3 lists the pre- and post- development run off rates for Outfall A for the 2-year through 100-year storm events. A summary of the peak flows and runoff volumes can be found in section 4.4 of this report. 4.2 Modifications to Existing Stormwater Facilities As previously mentioned in this report, the existing stormwater detention facility designed detain the runoff from the subject parcel and adjacent roads was found to be insufficiently sized to detain runoff rates produced by updated City of Bozeman design requirements. The facility was designed for the 10-year, 2-hour design storm. Per the newly adopted City of Bozeman Design and Construction Standards, detention facilities must now be sized for the 10-year, 24-hour and 100-year, 24-hour storm events, resulting in significantly higher runoff rates and volumes. In order to ensure enough storage is provided for runoff of existing roads, the proposed development, and runoff from the Phase 2 pond, the detention facility is required to be upsized. Currently, the facility, referred to as “Apex Pond” in the Gran Cielo Subdivision, Phase 2 stormwater design report (Appendix H.3) and the Gran Cielo Subdivision, Phase Page 8 of 11 2 As-builts (Appendix H.4), provides a storage volume of 9,687 cf. The pond has a base elevation of 4,941.5 feet and a top elevation of 4,943.0 feet. The outlet structure is designed with a weir to limit the flow rates and volume to pre-development conditions. Currently the weir is designed with a 14.75-inch-wide opening at an elevation of 4,942.49 feet, and an overflow elevation of 4,943.0 feet. The invert sits 2.48 feet above the approach channel. The proposed improvements to the detention facility and the associated outlet will detain stormwater runoff based on the updated design storm requirements. Specifically, the stormwater pond will be expanded to a volume of 31,975 cf with a bottom elevation of 4,940.0 feet and a top elevation of 4,944.0 feet. The proposed pond will also include a foot of gravel to provide additional void space storage and promote infiltration to native gravels. The additional gravel storage will also assist with treating the Water Quality event (first 0.5 inch of rainfall as required). The outlet weir is proposed to be raised up to an invert elevation of 4,943.60 and an overflow elevation of 4,944.0. The new invert will sit at 3.59 feet above the approach channel. See Appendix C.2 for additional facilities information. In addition to the detention facility, the conveyance structures were found to be insufficiently sized to convey the increased runoff volume from the proposed development. The specific pipes are analyzed using the 25-year, 24-hour flow rates produced by the hydraulic model and are found in Appendix D.4. An analysis of the existing pipes is found in Appendix E.1 and an exhibit is provided in Appendix E.2. The feasibility of upsizing the deficient pipes vs. installing new infrastructure is currently under review and will be established upon infrastructure review. 4.3 Groundwater Considerations Groundwater conditions were a primary concern with the redesign of the existing stormwater pond. The proposed detention facility was design to maintain two-foot separation between the seasonal high groundwater elevation and the bottom elevation of the storage facility. In the 2007 HKM geotechnical report, it is stated that seasonally high groundwater was observed at levels ranging from between 1-3 feet below ground surface within the area of the subject property. (Appendix H.1, Section 4.3 Groundwater, pg.10). These observations appear to be consistent with groundwater monitoring performed by WWC engineering from 2017-2018 for the first phase of the Gran Cielo Subdivision. The groundwater monitoring data from 2017-2018 is included in Appendix G of this report. In 2023 an updated geotechnical report was completed by Allied Engineering Services Inc. (AESI) in the phase 3 area (previously phase 4). In the AESI report, it is stated that it appears that groundwater levels have receded by approximately 3-8 feet in the vicinity of the Gran Cielo Subdivision as a result of development. (Appendix H.2 AESI, pg. 6, Groundwater Conditions) With this information, WWC estimates that the seasonally high groundwater elevation in the vicinity of the proposed stormwater pond to be at an elevation of approximately 4,938.0 feet, allowing for the pond bottom elevation to be lowered from its existing elevation of 4,941.5 feet by 1.5 feet to 4,940.0 feet. Page 9 of 11 4.4 Water Quality Treatment The proposed water quality treatment requirement of the first 0.5 inches of rainfall is considered in the overall design of the proposed stormwater facilities. The proposed detention pond is intended to infiltrate through native gravel layers during both major and minor storm events. The detention pond is designed with its outfall 3.0 feet above the bottom of the pond, ensuring any suspended solids are allowed enough time to settle prior to the pond discharging. Additionally, the water-quality event fills less than 0.5 feet of the detention pond, which is below the top of the gravel layer, ensuring the first 0.5 inches of rainfall plenty of time to infiltrate. 4.5 Pre-Development vs. Post-Development Comparison Post-development runoff rates and discharge volumes are designed to be less than or equal to the pre-development runoff conditions at the pond outfall location. This requirement is verified by the calculated post-development hydraulic modeling results provided in Appendix D.2. Outfall A includes a weir to help control the flow of runoff to ensure that the post- development runoff rates do not exceed pre-development runoff rates. The results of the hydraulic model showing the peak flows and volumes for each design storm are included in Appendix D.3 of this report and summarized in Table 2 below. The pre- and post- development flow rates and volumes for Outfall A are summarized in Table 3 and Table 4 below, representing minor (10-year, 24-hour) and major (100-year, 24-hour) storm events respectively. Table 2: Pre- and Post- Development Runoff Rates and Volumes Storm Event Pre Development Post-Development 2-yr, 24-hr 0.70 cfs 0.060 ac-ft 0.0 cfs 0.0 ac-ft 5-yr, 24-hr 1.38 cfs 0130 ac-ft 0.0 cfs 0.0 ac-ft 10-yr, 24-hr 1.91 cfs 0.190 ac-ft 0.12 cfs 0.055 ac-ft 25-yr, 24-hr 2.64 cfs 0.276 ac-ft 0.30 cfs 0.199 ac-ft 50-yr, 24-hr 3.22 cfs 0.347 ac-ft 0.56 cfs 0.309 ac-ft 100-yr, 24-hr 3.84 cfs 0.423 ac-ft 1.0 cfs 0.423 ac-ft Page 10 of 11 Table 3: Minor (10-year, 24-hour) Runoff Outfall Pre-Development Post-Development A 1.91 cfs 0.190 ac-ft 0.12 cfs 0.055 ac-ft Table 4: Major (100-year, 24-hour) Runoff Outfall Pre-Development Post-Development A 3.84 cfs 0.423 ac-ft 1.0 cfs 0.423 ac-ft 5. Evaluation of Major Storm Flood Risks The risk of a major storm event causing regional flooding was accounted for in the design of the stormwater management system. The Apex Pond detention facility was designed to release storm water at a rate below the pre-development flow rate and above the rate at which the facility would overtop. In the rare event in which the detention facility was to overtop, the runoff would flow to Apex Drive as it would historically in pre-development conditions. The detention facility was designed to encourage natural infiltration with a washed rock base extending down to native gravels. The subject property does not fall within a FEMA designated floodplains and is identified on the FIRMette as an area of minimal flood hazard (Zone X). No portion of the subject property is located within a Special Flood Hazard Area (SFHA). 6. Operation, Inspection, and Maintenance Considerations The property owner’s association will be responsible for the maintenance of the proposed stormwater facilities. This includes all detention facilities and outlet structures. A full Operation, Inspection, and Maintenance plan is included in Appendix F of this report. 7. References The following references were used in the preparation of this report. 1. City of Bozeman Design and Construction Standards (October 2024) 2. NRCS Technical Release 55 – Urban Hydrology for Small Watersheds (June 1986) 3. DEQ Circular 8, Montana Standards for Subdivision Storm Drainage, 2002 Edition 8. Conclusion The proposed stormwater drainage facilities for Gran Cielo Subdivision, Phase 3 have been designed to adequately convey, detain, and release the required minor and major storm events in compliance with the standards set forth in the City of Bozeman Design and Constructions Standards and DEQ Circular 8. The proposed design ensures that the post- development runoff rates and volumes are less than or equal to the pre-development conditions. The proposed detention facility is designed to manage the 100-year, 24-hour storm event, and provide treatment for the water-quality event. 9. Appendices A. NRCS Hydraulic Soil Groups Map and Summary B. Pre-Development Drainage Areas Page 11 of 11 C. Post-Development Conditions C.1 Post-Development Drainage Areas C.2 Post-Development Facilities C.3 Boulevard Infiltrator Example D. HydroCAD Modeling Inputs and Results D.1 Pre-Development Drainage Conditions D.2 Post-Development Drainage Conditions D.3 Pre- and Post-Development Outfall Rates D.4 25-yr, 24-hr Post-development Basin Runoffs E. Conveyance E.1 Analysis of Existing Conveyance Infrastructure E.2 Existing Conveyance Facilities Exhibit F. Operations, Inspection, and Maintenance Plan G. Groundwater Monitoring Well Data and Map H. References H.1 2007 HKM Geotechnical Report H.2 2023 Allied Engineering Services Inc. Geotechnical Report H.3 Gran Cielo Subdivision Phase 2 Stormwater Design Report H.4 Gran Cielo Subdivision Phase 2 As-Builts Hydrologic Soil Group—Gallatin County Area, Montana (Gran Cielo Subdivision, Phase 3) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/17/2025 Page 1 of 450555005055530505556050555905055620505565050556805055500505553050555605055590505562050556505055680494060494090494120494150494180494210494240494270494300494330494360 494060 494090 494120 494150 494180 494210 494240 494270 494300 494330 494360 45° 39' 17'' N 111° 4' 34'' W45° 39' 17'' N111° 4' 19'' W45° 39' 10'' N 111° 4' 34'' W45° 39' 10'' N 111° 4' 19'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 12N WGS84 0 50 100 200 300 Feet 0 20 40 80 120 Meters Map Scale: 1:1,510 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Gallatin County Area, Montana Survey Area Data: Version 29, Aug 30, 2025 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 18, 2022—Aug 29, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Hydrologic Soil Group—Gallatin County Area, Montana (Gran Cielo Subdivision, Phase 3) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/17/2025 Page 2 of 4 Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 457A Turner loam, moderately wet, 0 to 2 percent slopes B 6.6 98.6% 510B Meadowcreek loam, 0 to 4 percent slopes C 0.1 1.4% Totals for Area of Interest 6.7 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Hydrologic Soil Group—Gallatin County Area, Montana Gran Cielo Subdivision, Phase 3 Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/17/2025 Page 3 of 4 Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—Gallatin County Area, Montana Gran Cielo Subdivision, Phase 3 Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/17/2025 Page 4 of 4 W W W W SSSSSSSSSSSSSSSSWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW W W W WSSSSSSSS W W W W W W W WW WWWWWWWWWWWWWWWWWW WWWWWWSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSTSTSSSSSSSSSSSSSSSSSSSSSSSSSSSS STSTW W W W W W W W W W W W W W W SS SS SS SS SS SS SS W W W W STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTST STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTWWWWSSSSWWWW W W W W W W WWWSSS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SSDDDS PROPERTY LINEEASEMENT LINECURB AND GUTTERSANITARY SEWER MAINWATER MAINSTORMWATER MAINFIRE HYDRANTWATER FITTING VALVESANITARY SEWER MANHOLESTORMWATER MANHOLECOMBINATION INLETSDWLEGENDEXISTING APEX DRIVE (60' R.O.W.)EXISTING SOUTH 29TH AVENUE(60' R.O.W.) EXISTIN G S O U T H 2 7 T H A V E N U E (90' R.O. W . )EXISTING BENNETT BOULEVARD(60' R.O.W.)UNPLATTEDZONING R-4 PARCEL B COS 3098ZONING REMUPROPERTY LINEEASEMENT LINECURB AND GUTTERSANITARY SEWER MAINWATER MAINSTORMWATER MAINFIRE HYDRANTWATER FITTING VALVESANITARY SEWER MANHOLESTORMWATER MANHOLECOMBINATION INLETLEGENDGRAN CIELOSUBDIVISION PH 2PLAT J-717ZONING R-3GRAN C IELOSUBDIV IS ION PH 2PLAT J -717ZONING R -3GRAN C IELOSUBDIV IS ION PH 2PLAT J -7 17ZONING R -4UNPLATTEDZONING R -4CENTERLINE OFMIDDLE CREEK DITCHLATERAL. LOCATIONAPPROXIMATED FROMAERIAL IMAGERYEXISTING SOUTH 30TH AVENUE(60' R.O.W.)EXISTING SOUTH 29TH AVENUE(60' R.O.W.) EXISTING SOUTH 28TH AVENUE (60' R.O.W.) EXISTING SOUTH 27TH AVENUE (90' R.O.W.)EXISTING 15"PVC SEWERMAINEXISTING MIDDLECREEK DITCHPIPING. NOMODIFICATIONS TOCURRENT PIPING.EXISTING 8"PVC SEWERMAINEXISTING 21"RCP STORMMAINEXISTING 15"RCP STORMMAINEXISTING 18"RCP STORMMAINEXISTING8" DIWATERMAINEXISTING 15"RCP STORMMAINEXISTING 8" DIWATER MAINEXISTING 8" DIWATER MAINEXISTING 10"PVC SEWERMAINLOT 1, BLOCK 14,GRAN CIELO SUBDIVISION PH 2PLAT J-717LOT 3, BLOCK 14,GRAN CIELO SUBDIVISION PH 2PLAT J-717LOT 2, BLOCK 14,GRAN CIELO SUBDIVISION PH 2PLAT J-717LOT 4, BLOCK 14,GRAN CIELO SUBDIVISION PH 2PLAT J-717494949 4 8 49474 9 4 6 4 94 5 4 9 4 4 4 9 4 349504 9 5 1 495249534954OPEN SPACE C,BLOCK 14,GRAN CIELOSUBDIVISION PH 2PLAT J-717EXISTINGSTORMWATERPONDEXISTING 48"OUTFALLEXISTING 15" PVCSTORM MAIN0SCALE: 1" = 40'40'20'K:\Bozeman\Bozeman Haus LLC\2025380 Gran Cielo 1 – Phase 3\05CAD\Sheets\EXISTING.dwg SUBD LAYOUT 1/26/2026 3:42:24 PM DESIGNED BY:DRAWN BY:CHECKED BY:DATE:EWRHDWEWR01/27/2026SHEET1NO.DATEREVISIONPREPARED BY BY EXISTING CONDITIONS EXHIBIT BOZEMAN, MT BOZEMAN HAUS, LLC. ENGINEERING PROJECT NO. 2025380 895 TECHNOLOGY BLVD., SUITE 203 BOZEMAN, MT 59718 (406) 586-0262 www.wwcengineering.com GRAN CIELO SUBDIVISION, PHASE 3SSSSWWSTST Basin A16.694 ac +/-Basin S12.458 ac +/- STSTSTSTSTSTSTSTST STSTSTSTSTSTSTSTSTDDDSTSTSTSTSTSTSTSTST STSTSTSTSTSTSTSTSTDDDK:\Bozeman\Bozeman Haus LLC\2025380 Gran Cielo 1 – Phase 3\05CAD\Sheets\DA MAP.dwg 11X17 LAND 1/26/2026 6:23:23 PM 0SCALE: 1" = 80'80'40'DESIGNED BY:DRAWN BY:CHECKED BY:DATE:EWRHDWEWR01/27/2026SHEET1NO.DATEREVISIONPREPARED BY BY DRAINAGE AREA EXHIBIT BOZEMAN HAUS, LLC BOZEMAN, MONTANA GRAN CIELO SUBDIVISON, PHASE 3 ENGINEERING PROJECT NO. 2025380 895 TECHNOLOGY BLVD., SUITE 203 BOZEMAN, MT 59718 (406) 586-0262 www.wwcengineering.com STSTSTSTSTSTSTSTST STSTSTSTSTSTSTSTSTDDDSTSTSTSTSTSTSTSTST STSTSTSTSTSTSTSTSTDDD(P) DETENTION POND 98'x134'TOP = 4,944.0BOTTOM = 4,941.0STORAGE VOLUME = 31,975 CF(P) 6'X110'BOULEVARDINFILTRATOR OUTFALL A(P) 18" WIDE WEIR INV 4,943.60OVERFLOW 4,944.00(P) TEMPORARY RETENTIONPOND 18.5'x105'BOTTOM = 4,945.0TOP = 4,947.0STORAGE VOLUME = 2,945 CF(E) 15" A-2000 PVCL=31 LF S=1.9% (E) 15" A-2000 PVCL=240 LF S=2.11%(E) 15" A-2000 PVCL=264 LF S=1.07% (E) 15" A-2000 PVCL=38 LF S=1.05%(E) COMBOINLET 24"x36"(E) COMBOINLET 24"x36"(E) COMBOINLET 24"x36"(E) COMBOINLET 24"x36"(E) COMBOINLET 24"x36"(E) COMBOINLET 24"x36"(E) COMBOINLET 24"x36"(E) 2X COMBOINLET 24"x36"(E) 24" CLASS IV RCPL=30 LF S=0.6%(E) 15" CLASS IVRCPL=46 LF S=0.50% (E) 18" A-2000 PVCL=27 LF S=2.0%(E) 15" A-2000 PVCL=311 LF S=0.37%(E) 18" CLASS IV RCPL=267 LF S=0.57%BLOCK 8 BLOCK 6 BLOCK 7 BLOCK 5 BLOCK 3 BLOCK 2 BLOCK 1BLOCK 4 K:\Bozeman\Bozeman Haus LLC\2025380 Gran Cielo 1 – Phase 3\05CAD\Sheets\Post Dev Conditions.dwg 11X17 LAND 1/27/2026 7:29:15 PM 0SCALE: 1" = 80'80'40'DESIGNED BY:DRAWN BY:CHECKED BY:DATE:EWRHDWEWR01/27/2026SHEET1NO.DATEREVISIONPREPARED BY BY POST-DEVELOPMENT CONDITIONS BOZEMAN HAUS, LLC BOZEMAN, MONTANA GRAN CIELO SUBDIVISON, PHASE 3 ENGINEERING PROJECT NO. 2025380 895 TECHNOLOGY BLVD., SUITE 203 BOZEMAN, MT 59718 (406) 586-0262 www.wwcengineering.com WWWWWWWWWWWSTSTSTSTSTSTSTSTSTSTWWWSDWWWWWWWWSSSSSSSSSSSSWWWWWWWWWWWSTSTSTSTSTSTSTSTSTSTWWWSDS(P) DETENTION POND 98'x134'TOP = 4,944.0BOTTOM = 4,9410STORAGE VOLUME = 31,975 CF OUTFALL A(P) 18" WIDE WEIR INV 4,943.60OVERFLOW 4,944.00TO REPLACE EXISTING 14.25"WEIR(E) 15" A-2000 PVCL=31 LF S=1.9%PIPE TO BE MODIFIED FOR NEWBOTTOM OF POND ELEVATION(E) COMBO INLET 24"x36"(E) COMBO INLET24"x36"(E) COMBO INLET 24"x36"(E) COMBO INLET 24"x36"(E) 24" CLASS IV RCPL=30 LF S=0.6%(E) 15" CLASS IV RCPL=46 LF S=0.50% (E) 18" A-2000 PVCL=27 LF S=2.0%(E) 18" CLASS IV RCPL=267 LF S=0.57%4' SAFETY BENCH (TYP.)LOT 1EXISTING APEX DRIVE (60' R.O.W.)ALLEY(30' RIGHT-OF-WAY)NATIVE GRAVEL BASE-25.00%-33.33%-33.33%-25.00%4941494249434943494410' DETENTIONFACILITY SETBACKEXISTING SOUTH 29TH AVENUE(60' R.O.W.)4' SAFETY BENCHBOTTOM OF POND/TOP OF GRAVEL4H:1V3H:1V3'TOP OF PONDELEV=4,941.0'ELEV=4,938.0'(SEASONAL HIGH GW)3" DIA FREE DRAINING ROUNDROCK FROM FINISHED GRADE TO12" BELOW NATIVE GRAVEL LAYER6" TOPSOIL2.5'ELEV=4,944.0'STAGE STORAGE TABLEELEVAREA(sq. ft.)DEPTH(ft)AVG ENDINC. VOL.(cu. ft.)AVG ENDTOTAL VOL.(cu. ft.)CONICINC. VOL.(cu. ft.)CONICTOTAL VOL.(cu. ft.)4,941.00007,367.7703N/AN/A0.0000N/A0.00004,941.50007,895.46570.50003815.80903815.80903815.04863815.04864,942.00008,449.63480.50004086.27517902.08414085.49207900.54064,942.50009,022.75460.50004368.097412270.18154367.313812267.85454,943.00009,607.58560.50004657.585116927.76654656.819916924.67444,943.0 (Start of 4'bench)11,248.18120.00000.000016927.76650.000016924.67444,943.500012,105.82280.50005838.501022766.26755837.188222761.86274,944.000012,989.25280.50006273.768929040.03646272.472729034.3353WWWWSSSSSSSSW W WSTST SW WW SS SS SS SS SSWWW WSSSSSSSSW W WSTST SW WW SS SS SS SS SS (P) TEMPORARY RETENTION POND 18.5'x105'TOP = 4,947.0BOTTOM = 4,945.0STORAGE VOLUME = 2,945 CF-50.00%-50.00%EXISTING APEX DRIVE (60' R.O.W.)EXISTING S. 27TH AVE (90' R.O.W.)(P) 2' CURB CUT TO RIP-RAPLINED CHANNELLOT 8LOT 7NATIVE GRAVEL BASEBOTTOM OF POND/TOP OF GRAVEL2H:1VTOP OF PONDELEV=4,940.19'(SEASONAL HIGH GW)3" DIA FREE DRAINING ROUNDROCK FROM FINISHED GRADE TO12" BELOW NATIVE GRAVEL LAYER6" TOPSOILELEV=4,947.0'ELEV=4,945.0'2'4.81'STAGE STORAGE TABLEELEVAREA(sq. ft.)DEPTH(ft)AVG ENDINC. VOL.(cu. ft.)AVG ENDTOTAL VOL.(cu. ft.)CONICINC. VOL.(cu. ft.)CONICTOTAL VOL.(cu. ft.)4,945.00001,034.8950N/AN/A0.0000N/A0.00004,945.50001,237.88100.5000568.1940568.1940567.4371567.43714,946.00001,465.67900.5000675.89001244.0840675.08881242.52594,946.50001,701.87630.5000791.88882035.9728791.15402033.67994,947.00001,948.00230.5000912.46972948.4425911.77732945.4572K:\Bozeman\Bozeman Haus LLC\2025380 Gran Cielo 1 – Phase 3\05CAD\Sheets\Post Dev Conditions.dwg POND PROFILES 1/27/2026 6:53:46 PM 0SCALE: 1" = 40'40'20'DESIGNED BY:DRAWN BY:CHECKED BY:DATE:EWRHDWEWR01/27/2026SHEET2NO.DATEREVISIONPREPARED BY BY ENGINEERING PROJECT NO. 2025380 895 TECHNOLOGY BLVD., SUITE 203 BOZEMAN, MT 59718 (406) 586-0262 www.wwcengineering.com POST-DEVELOPMENT PROFILES BOZEMAN HAUS, LLC BOZEMAN, MONTANA GRAN CIELO SUBDIVISON, PHASE 3 0SCALE: 1" = 40'40'20'APEX POND PROFILE VIEWSCALE: NOT TO SCALES. 27TH POND PROFILE VIEWSCALE: NOT TO SCALE (P) 6'X110' BOULEVARDINFILTRATORPROPOSED SOUTH 28TH AVENUE(60' R.O.W.)BOTTOM OF POND/TOP OF GRAVELELEV=4,944.85(SEASONAL HIGH GW)3" DIA FREE DRAINING ROUNDROCK FROM FINISHED GRADE TO12" BELOW NATIVE GRAVEL LAYER4" CONCRETE SIDEWALKELEV=4,950.5'ELEV=4,949.5'CURB CUTCONCRETE WALL (TYP.)CL S. 28TH17.5'11.5'5.5'K:\Bozeman\Bozeman Haus LLC\2025380 Gran Cielo 1 – Phase 3\05CAD\Sheets\Post Dev Conditions.dwg POND PROFILES (2) 1/27/2026 6:53:46 PM DESIGNED BY:DRAWN BY:CHECKED BY:DATE:EWRHDWEWR01/27/2026SHEET3NO.DATEREVISIONPREPARED BY BY ENGINEERING PROJECT NO. 2025380 895 TECHNOLOGY BLVD., SUITE 203 BOZEMAN, MT 59718 (406) 586-0262 www.wwcengineering.com POST-DEVELOPMENT PROFILES BOZEMAN HAUS, LLC BOZEMAN, MONTANA GRAN CIELO SUBDIVISON, PHASE 3 0SCALE: 1" = 20'2010BOULEVARD INFILTRATOR PROFILE VIEWSCALE: NOT TO SCALE Figure 2 - Boulevard Infiltrator Dry A1 Basin A1 S1 Existing Roadways A0 Outfall A (Apex Pond Outfall) Routing Diagram for GC3 Pre-Development Conditions Prepared by WWC Engineering, Printed 11/20/2025 HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Subcat Reach Pond Link GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 2HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 10-yr, 24-hr Type II 24-hr Default 24.00 1 1.70 2 2 100-yr, 24-hr Type II 24-hr Default 24.00 1 2.34 2 GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 3HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 1.008 61 >75% Grass cover, Good, HSG B (S1) 6.590 71 Herbaceous range, Fair, HSG B (A1) 0.104 81 Herbaceous range, Fair, HSG C (A1) 1.450 98 Paved roads w/curbs & sewers, HSG B (S1) 9.153 74 TOTAL AREA GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 4HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 9.048 HSG B A1, S1 0.104 HSG C A1 0.000 HSG D 0.000 Other 9.153 TOTAL AREA GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 5HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 1.008 0.000 0.000 0.000 1.008 >75% Grass cover, Good S1 0.000 6.590 0.104 0.000 0.000 6.694 Herbaceous range, Fair A1 0.000 1.450 0.000 0.000 0.000 1.450 Paved roads w/curbs & sewers S1 0.000 9.048 0.104 0.000 0.000 9.153 TOTAL AREA Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 6HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Time span=1.00-30.00 hrs, dt=0.01 hrs, 2901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=291,612 sf 0.00% Impervious Runoff Depth=0.16"Subcatchment A1: Basin A1 Flow Length=667' Slope=0.0130 '/' Tc=37.3 min CN=71 Runoff=0.36 cfs 0.088 af Runoff Area=107,092 sf 58.98% Impervious Runoff Depth=0.50"Subcatchment S1: Existing Roadways Flow Length=1,473' Tc=9.1 min CN=83 Runoff=1.89 cfs 0.102 af Inflow=1.91 cfs 0.190 afPond A0: Outfall A (Apex Pond Outfall) Primary=1.91 cfs 0.190 af Total Runoff Area = 9.153 ac Runoff Volume = 0.190 af Average Runoff Depth = 0.25" 84.16% Pervious = 7.703 ac 15.84% Impervious = 1.450 ac Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 7HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A1: Basin A1 Runoff = 0.36 cfs @ 12.51 hrs, Volume= 0.088 af, Depth= 0.16" Routed to Pond A0 : Outfall A (Apex Pond Outfall) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Type II 24-hr 10-yr, 24-hr Rainfall=1.70" Area (sf) CN Description 287,060 71 Herbaceous range, Fair, HSG B 4,552 81 Herbaceous range, Fair, HSG C 291,612 71 Weighted Average 291,612 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.5 150 0.0130 0.09 Sheet Flow, Grass: Short n= 0.150 P2= 1.18" 10.8 517 0.0130 0.80 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 37.3 667 Total Subcatchment A1: Basin A1 Runoff Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type II 24-hr 10-yr 24-hr Rainfall=1.70" Runoff Area=291,612 sf Runoff Volume=0.088 af Runoff Depth=0.16" Flow Length=667' Slope=0.0130 '/' Tc=37.3 min CN=71 0.36 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 8HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment S1: Existing Roadways Runoff = 1.89 cfs @ 12.02 hrs, Volume= 0.102 af, Depth= 0.50" Routed to Pond A0 : Outfall A (Apex Pond Outfall) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Type II 24-hr 10-yr, 24-hr Rainfall=1.70" Area (sf) CN Description 63,164 98 Paved roads w/curbs & sewers, HSG B 43,928 61 >75% Grass cover, Good, HSG B 107,092 83 Weighted Average 43,928 41.02% Pervious Area 63,164 58.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Asphalt Sheet Flow Smooth surfaces n= 0.011 P2= 1.18" 4.3 745 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 1.2 311 0.0037 4.16 5.11 Pipe Channel, Pipe 1 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.010 PVC, smooth interior 0.8 267 0.0057 5.30 9.37 Pipe Channel, Pipe 2 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 9.1 1,473 Total Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 9HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Subcatchment S1: Existing Roadways Runoff Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Type II 24-hr 10-yr 24-hr Rainfall=1.70" Runoff Area=107,092 sf Runoff Volume=0.102 af Runoff Depth=0.50" Flow Length=1,473' Tc=9.1 min CN=83 1.89 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 10HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 15.84% Impervious, Inflow Depth = 0.25" for 10-yr, 24-hr event Inflow = 1.91 cfs @ 12.02 hrs, Volume= 0.190 af Primary = 1.91 cfs @ 12.02 hrs, Volume= 0.190 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Inflow Area=9.153 ac 1.91 cfs1.91 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 11HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Time span=1.00-30.00 hrs, dt=0.01 hrs, 2901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=291,612 sf 0.00% Impervious Runoff Depth=0.41"Subcatchment A1: Basin A1 Flow Length=667' Slope=0.0130 '/' Tc=37.3 min CN=71 Runoff=1.52 cfs 0.231 af Runoff Area=107,092 sf 58.98% Impervious Runoff Depth=0.94"Subcatchment S1: Existing Roadways Flow Length=1,473' Tc=9.1 min CN=83 Runoff=3.66 cfs 0.192 af Inflow=3.84 cfs 0.423 afPond A0: Outfall A (Apex Pond Outfall) Primary=3.84 cfs 0.423 af Total Runoff Area = 9.153 ac Runoff Volume = 0.423 af Average Runoff Depth = 0.55" 84.16% Pervious = 7.703 ac 15.84% Impervious = 1.450 ac Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 12HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A1: Basin A1 Runoff = 1.52 cfs @ 12.40 hrs, Volume= 0.231 af, Depth= 0.41" Routed to Pond A0 : Outfall A (Apex Pond Outfall) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Type II 24-hr 100-yr, 24-hr Rainfall=2.34" Area (sf) CN Description 287,060 71 Herbaceous range, Fair, HSG B 4,552 81 Herbaceous range, Fair, HSG C 291,612 71 Weighted Average 291,612 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 26.5 150 0.0130 0.09 Sheet Flow, Grass: Short n= 0.150 P2= 1.18" 10.8 517 0.0130 0.80 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 37.3 667 Total Subcatchment A1: Basin A1 Runoff Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Type II 24-hr 100-yr 24-hr Rainfall=2.34" Runoff Area=291,612 sf Runoff Volume=0.231 af Runoff Depth=0.41" Flow Length=667' Slope=0.0130 '/' Tc=37.3 min CN=71 1.52 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 13HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment S1: Existing Roadways Runoff = 3.66 cfs @ 12.01 hrs, Volume= 0.192 af, Depth= 0.94" Routed to Pond A0 : Outfall A (Apex Pond Outfall) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Type II 24-hr 100-yr, 24-hr Rainfall=2.34" Area (sf) CN Description 63,164 98 Paved roads w/curbs & sewers, HSG B 43,928 61 >75% Grass cover, Good, HSG B 107,092 83 Weighted Average 43,928 41.02% Pervious Area 63,164 58.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Asphalt Sheet Flow Smooth surfaces n= 0.011 P2= 1.18" 4.3 745 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 1.2 311 0.0037 4.16 5.11 Pipe Channel, Pipe 1 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.010 PVC, smooth interior 0.8 267 0.0057 5.30 9.37 Pipe Channel, Pipe 2 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 9.1 1,473 Total Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 14HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Subcatchment S1: Existing Roadways Runoff Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)4 3 2 1 0 Type II 24-hr 100-yr 24-hr Rainfall=2.34" Runoff Area=107,092 sf Runoff Volume=0.192 af Runoff Depth=0.94" Flow Length=1,473' Tc=9.1 min CN=83 3.66 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 15HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 15.84% Impervious, Inflow Depth = 0.55" for 100-yr, 24-hr event Inflow = 3.84 cfs @ 12.02 hrs, Volume= 0.423 af Primary = 3.84 cfs @ 12.02 hrs, Volume= 0.423 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)4 3 2 1 0 Inflow Area=9.153 ac 3.84 cfs3.84 cfs A1 Basin A1 A2 Basin A2 A3 Basin A3 S1 Existing Roadways S2 S27th East 1/2 A0 Outfall A (Apex Pond Outfall) P1 Apex Pond P2 S27th Blvd Pond (Temporary) R1 Blvd Infiltrator Routing Diagram for GC3 Post-Development Prepared by WWC Engineering, Printed 11/20/2025 HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Subcat Reach Pond Link GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 2HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 10-yr, 24-hr Type II 24-hr Default 24.00 1 1.70 2 2 100-yr, 24-hr Type II 24-hr Default 24.00 1 2.34 2 GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 3HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 5.726 85 1/8 acre lots, 65% imp, HSG B (A1, A2, A3) 0.104 90 1/8 acre lots, 65% imp, HSG C (A3) 1.031 61 >75% Grass cover, Good, HSG B (S1, S2) 0.363 98 Paved parking, HSG B (A3) 2.337 98 Paved roads w/curbs & sewers, HSG B (A1, S1, S2) 9.561 86 TOTAL AREA GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 4HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 9.457 HSG B A1, A2, A3, S1, S2 0.104 HSG C A3 0.000 HSG D 0.000 Other 9.561 TOTAL AREA GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 5HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 5.726 0.104 0.000 0.000 5.830 1/8 acre lots, 65% imp A1, A2, A3 0.000 1.031 0.000 0.000 0.000 1.031 >75% Grass cover, Good S1, S2 0.000 0.363 0.000 0.000 0.000 0.363 Paved parking A3 0.000 2.337 0.000 0.000 0.000 2.337 Paved roads w/curbs & sewers A1, S1, S2 0.000 9.457 0.104 0.000 0.000 9.561 TOTAL AREA Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 6HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Time span=1.00-40.00 hrs, dt=0.01 hrs, 3901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=152,099 sf 70.02% Impervious Runoff Depth=0.68"Subcatchment A1: Basin A1 Flow Length=628' Tc=58.9 min CN=87 Runoff=1.23 cfs 0.197 af Runoff Area=51,274 sf 65.00% Impervious Runoff Depth=0.58"Subcatchment A2: Basin A2 Flow Length=267' Slope=0.0200 '/' Tc=3.5 min CN=85 Runoff=1.35 cfs 0.057 af Runoff Area=88,224 sf 71.28% Impervious Runoff Depth=0.73"Subcatchment A3: Basin A3 Flow Length=719' Slope=0.0200 '/' Tc=26.1 min CN=88 Runoff=1.38 cfs 0.123 af Runoff Area=107,092 sf 58.98% Impervious Runoff Depth=0.50"Subcatchment S1: Existing Roadways Flow Length=1,473' Tc=9.1 min CN=83 Runoff=1.89 cfs 0.102 af Runoff Area=17,807 sf 94.59% Impervious Runoff Depth=1.29"Subcatchment S2: S27th East 1/2 Flow Length=650' Slope=0.0200 '/' Tc=5.7 min CN=96 Runoff=0.89 cfs 0.044 af Inflow=0.12 cfs 0.055 afPond A0: Outfall A (Apex Pond Outfall) Primary=0.12 cfs 0.055 af Peak Elev=4,943.69' Storage=18,403 cf Inflow=3.13 cfs 0.459 afPond P1: Apex Pond Outflow=0.12 cfs 0.055 af Peak Elev=4,946.47' Storage=0.044 af Inflow=0.89 cfs 0.044 afPond P2: S27th Blvd Pond (Temporary) Outflow=0.00 cfs 0.000 af Peak Elev=4,950.12' Storage=973 cf Inflow=1.35 cfs 0.057 afPond R1: Blvd Infiltrator Outflow=0.28 cfs 0.037 af Total Runoff Area = 9.561 ac Runoff Volume = 0.524 af Average Runoff Depth = 0.66" 32.12% Pervious = 3.071 ac 67.88% Impervious = 6.490 ac Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 7HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A1: Basin A1 Runoff = 1.23 cfs @ 12.63 hrs, Volume= 0.197 af, Depth= 0.68" Routed to Pond P1 : Apex Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 10-yr, 24-hr Rainfall=1.70" Area (sf) CN Description 130,298 85 1/8 acre lots, 65% imp, HSG B 21,801 98 Paved roads w/curbs & sewers, HSG B 152,099 87 Weighted Average 45,604 29.98% Pervious Area 106,495 70.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 56.1 150 0.0020 0.04 Sheet Flow, Landscape Sheet Flow Grass: Short n= 0.150 P2= 1.18" 2.8 478 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 58.9 628 Total Subcatchment A1: Basin A1 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Type II 24-hr 10-yr 24-hr Rainfall=1.70" Runoff Area=152,099 sf Runoff Volume=0.197 af Runoff Depth=0.68" Flow Length=628' Tc=58.9 min CN=87 1.23 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 8HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A2: Basin A2 Runoff = 1.35 cfs @ 11.95 hrs, Volume= 0.057 af, Depth= 0.58" Routed to Pond R1 : Blvd Infiltrator Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 10-yr, 24-hr Rainfall=1.70" Area (sf) CN Description 51,274 85 1/8 acre lots, 65% imp, HSG B 17,946 35.00% Pervious Area 33,328 65.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Asphalt Sheet Flow Smooth surfaces n= 0.011 P2= 1.18" 0.7 117 0.0200 2.87 Shallow Concentrated Flow, Shallow Concentrated Paved Kv= 20.3 fps 3.5 267 Total Subcatchment A2: Basin A2 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Type II 24-hr 10-yr 24-hr Rainfall=1.70" Runoff Area=51,274 sf Runoff Volume=0.057 af Runoff Depth=0.58" Flow Length=267' Slope=0.0200 '/' Tc=3.5 min CN=85 1.35 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 9HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A3: Basin A3 Runoff = 1.38 cfs @ 12.21 hrs, Volume= 0.123 af, Depth= 0.73" Routed to Pond P1 : Apex Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 10-yr, 24-hr Rainfall=1.70" Area (sf) CN Description 67,849 85 1/8 acre lots, 65% imp, HSG B 15,823 98 Paved parking, HSG B 4,552 90 1/8 acre lots, 65% imp, HSG C 88,224 88 Weighted Average 25,340 28.72% Pervious Area 62,884 71.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 22.3 150 0.0200 0.11 Sheet Flow, Landscape Sheet Flow Grass: Short n= 0.150 P2= 1.18" 0.8 50 0.0200 0.99 Shallow Concentrated Flow, Landscape Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 3.0 519 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 26.1 719 Total Subcatchment A3: Basin A3 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Type II 24-hr 10-yr 24-hr Rainfall=1.70" Runoff Area=88,224 sf Runoff Volume=0.123 af Runoff Depth=0.73" Flow Length=719' Slope=0.0200 '/' Tc=26.1 min CN=88 1.38 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 10HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment S1: Existing Roadways Runoff = 1.89 cfs @ 12.02 hrs, Volume= 0.102 af, Depth= 0.50" Routed to Pond P1 : Apex Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 10-yr, 24-hr Rainfall=1.70" Area (sf) CN Description 63,164 98 Paved roads w/curbs & sewers, HSG B 43,928 61 >75% Grass cover, Good, HSG B 107,092 83 Weighted Average 43,928 41.02% Pervious Area 63,164 58.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Asphalt Sheet Flow Smooth surfaces n= 0.011 P2= 1.18" 4.3 745 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 1.2 311 0.0037 4.16 5.11 Pipe Channel, Pipe 1 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.010 PVC, smooth interior 0.8 267 0.0057 5.30 9.37 Pipe Channel, Pipe 2 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 9.1 1,473 Total Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 11HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Subcatchment S1: Existing Roadways Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Type II 24-hr 10-yr 24-hr Rainfall=1.70" Runoff Area=107,092 sf Runoff Volume=0.102 af Runoff Depth=0.50" Flow Length=1,473' Tc=9.1 min CN=83 1.89 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 12HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment S2: S27th East 1/2 Runoff = 0.89 cfs @ 11.97 hrs, Volume= 0.044 af, Depth= 1.29" Routed to Pond P2 : S27th Blvd Pond (Temporary) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 10-yr, 24-hr Rainfall=1.70" Area (sf) CN Description 16,843 98 Paved roads w/curbs & sewers, HSG B 964 61 >75% Grass cover, Good, HSG B 17,807 96 Weighted Average 964 5.41% Pervious Area 16,843 94.59% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.18" 2.9 500 0.0200 2.87 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 5.7 650 Total Subcatchment S2: S27th East 1/2 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type II 24-hr 10-yr 24-hr Rainfall=1.70" Runoff Area=17,807 sf Runoff Volume=0.044 af Runoff Depth=1.29" Flow Length=650' Slope=0.0200 '/' Tc=5.7 min CN=96 0.89 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 13HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth > 0.07" for 10-yr, 24-hr event Inflow = 0.12 cfs @ 24.02 hrs, Volume= 0.055 af Primary = 0.12 cfs @ 24.02 hrs, Volume= 0.055 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=9.153 ac 0.12 cfs0.12 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 14HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P1: Apex Pond Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth = 0.60" for 10-yr, 24-hr event Inflow = 3.13 cfs @ 12.05 hrs, Volume= 0.459 af Outflow = 0.12 cfs @ 24.02 hrs, Volume= 0.055 af, Atten= 96%, Lag= 718.3 min Primary = 0.12 cfs @ 24.02 hrs, Volume= 0.055 af Routed to Pond A0 : Outfall A (Apex Pond Outfall) Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,943.69' @ 24.02 hrs Surf.Area= 8,929 sf Storage= 18,403 cf Plug-Flow detention time= 725.4 min calculated for 0.055 af (12% of inflow) Center-of-Mass det. time= 556.8 min ( 1,439.7 - 882.9 ) Volume Invert Avail.Storage Storage Description #1 4,940.00' 21,250 cf Custom Stage Data (Conic) Listed below Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,940.00 3,863 0.0 0 0 3,863 4,941.00 3,863 40.0 1,545 1,545 4,083 4,941.50 4,656 100.0 2,127 3,672 4,885 4,942.00 5,548 100.0 2,548 6,220 5,786 4,942.50 6,493 100.0 3,007 9,227 6,741 4,943.00 7,486 100.0 3,492 12,719 7,745 4,943.50 8,525 100.0 4,000 16,719 8,796 4,944.00 9,613 100.0 4,532 21,250 9,897 Device Routing Invert Outlet Devices #1 Primary 4,943.60'1.5' long x 0.40' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 3.6' Crest Height Primary OutFlow Max=0.12 cfs @ 24.02 hrs HW=4,943.69' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 0.12 cfs @ 0.96 fps) Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 15HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond P1: Apex Pond Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)3 2 1 0 Inflow Area=9.153 ac Peak Elev=4,943.69' Storage=18,403 cf 3.13 cfs 0.12 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 16HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P2: S27th Blvd Pond (Temporary) Inflow Area = 0.409 ac, 94.59% Impervious, Inflow Depth = 1.29" for 10-yr, 24-hr event Inflow = 0.89 cfs @ 11.97 hrs, Volume= 0.044 af Outflow = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,946.47' @ 24.33 hrs Surf.Area= 0.043 ac Storage= 0.044 af Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 4,945.00' 0.070 af 10.00'W x 75.00'L x 2.00'H Prismatoid Z=4.0 Pond P2: S27th Blvd Pond (Temporary) Inflow Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.409 ac Peak Elev=4,946.47' Storage=0.044 af 0.89 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 17HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond R1: Blvd Infiltrator Inflow Area = 1.177 ac, 65.00% Impervious, Inflow Depth = 0.58" for 10-yr, 24-hr event Inflow = 1.35 cfs @ 11.95 hrs, Volume= 0.057 af Outflow = 0.28 cfs @ 12.07 hrs, Volume= 0.037 af, Atten= 79%, Lag= 7.4 min Primary = 0.28 cfs @ 12.07 hrs, Volume= 0.037 af Routed to Pond P1 : Apex Pond Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,950.12' @ 12.07 hrs Surf.Area= 600 sf Storage= 973 cf Plug-Flow detention time= 209.9 min calculated for 0.037 af (64% of inflow) Center-of-Mass det. time= 87.4 min ( 940.3 - 852.9 ) Volume Invert Avail.Storage Storage Description #1 4,947.00' 1,200 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,947.00 600 0.0 0 0 600 4,948.00 600 40.0 240 240 687 4,949.00 600 40.0 240 480 774 4,949.50 600 40.0 120 600 817 4,950.00 600 100.0 300 900 860 4,950.50 600 100.0 300 1,200 904 Device Routing Invert Outlet Devices #1 Primary 4,950.00'2.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=0.28 cfs @ 12.07 hrs HW=4,950.12' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 0.28 cfs @ 1.14 fps) Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 18HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond R1: Blvd Infiltrator Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Inflow Area=1.177 ac Peak Elev=4,950.12' Storage=973 cf 1.35 cfs 0.28 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 19HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Time span=1.00-40.00 hrs, dt=0.01 hrs, 3901 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=152,099 sf 70.02% Impervious Runoff Depth=1.18"Subcatchment A1: Basin A1 Flow Length=628' Tc=58.9 min CN=87 Runoff=2.21 cfs 0.343 af Runoff Area=51,274 sf 65.00% Impervious Runoff Depth=1.05"Subcatchment A2: Basin A2 Flow Length=267' Slope=0.0200 '/' Tc=3.5 min CN=85 Runoff=2.44 cfs 0.103 af Runoff Area=88,224 sf 71.28% Impervious Runoff Depth=1.25"Subcatchment A3: Basin A3 Flow Length=719' Slope=0.0200 '/' Tc=26.1 min CN=88 Runoff=2.39 cfs 0.210 af Runoff Area=107,092 sf 58.98% Impervious Runoff Depth=0.94"Subcatchment S1: Existing Roadways Flow Length=1,473' Tc=9.1 min CN=83 Runoff=3.66 cfs 0.192 af Runoff Area=17,807 sf 94.59% Impervious Runoff Depth=1.90"Subcatchment S2: S27th East 1/2 Flow Length=650' Slope=0.0200 '/' Tc=5.7 min CN=96 Runoff=1.29 cfs 0.065 af Inflow=1.00 cfs 0.423 afPond A0: Outfall A (Apex Pond Outfall) Primary=1.00 cfs 0.423 af Peak Elev=4,943.95' Storage=20,837 cf Inflow=7.28 cfs 0.828 afPond P1: Apex Pond Outflow=1.00 cfs 0.423 af Peak Elev=4,946.91' Storage=0.065 af Inflow=1.29 cfs 0.065 afPond P2: S27th Blvd Pond (Temporary) Outflow=0.00 cfs 0.000 af Peak Elev=4,950.50' Storage=1,200 cf Inflow=2.44 cfs 0.103 afPond R1: Blvd Infiltrator Outflow=2.19 cfs 0.083 af Total Runoff Area = 9.561 ac Runoff Volume = 0.913 af Average Runoff Depth = 1.15" 32.12% Pervious = 3.071 ac 67.88% Impervious = 6.490 ac Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 20HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A1: Basin A1 Runoff = 2.21 cfs @ 12.63 hrs, Volume= 0.343 af, Depth= 1.18" Routed to Pond P1 : Apex Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 100-yr, 24-hr Rainfall=2.34" Area (sf) CN Description 130,298 85 1/8 acre lots, 65% imp, HSG B 21,801 98 Paved roads w/curbs & sewers, HSG B 152,099 87 Weighted Average 45,604 29.98% Pervious Area 106,495 70.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 56.1 150 0.0020 0.04 Sheet Flow, Landscape Sheet Flow Grass: Short n= 0.150 P2= 1.18" 2.8 478 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 58.9 628 Total Subcatchment A1: Basin A1 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Type II 24-hr 100-yr 24-hr Rainfall=2.34" Runoff Area=152,099 sf Runoff Volume=0.343 af Runoff Depth=1.18" Flow Length=628' Tc=58.9 min CN=87 2.21 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 21HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A2: Basin A2 Runoff = 2.44 cfs @ 11.95 hrs, Volume= 0.103 af, Depth= 1.05" Routed to Pond R1 : Blvd Infiltrator Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 100-yr, 24-hr Rainfall=2.34" Area (sf) CN Description 51,274 85 1/8 acre lots, 65% imp, HSG B 17,946 35.00% Pervious Area 33,328 65.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Asphalt Sheet Flow Smooth surfaces n= 0.011 P2= 1.18" 0.7 117 0.0200 2.87 Shallow Concentrated Flow, Shallow Concentrated Paved Kv= 20.3 fps 3.5 267 Total Subcatchment A2: Basin A2 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Type II 24-hr 100-yr 24-hr Rainfall=2.34" Runoff Area=51,274 sf Runoff Volume=0.103 af Runoff Depth=1.05" Flow Length=267' Slope=0.0200 '/' Tc=3.5 min CN=85 2.44 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 22HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A3: Basin A3 Runoff = 2.39 cfs @ 12.21 hrs, Volume= 0.210 af, Depth= 1.25" Routed to Pond P1 : Apex Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 100-yr, 24-hr Rainfall=2.34" Area (sf) CN Description 67,849 85 1/8 acre lots, 65% imp, HSG B 15,823 98 Paved parking, HSG B 4,552 90 1/8 acre lots, 65% imp, HSG C 88,224 88 Weighted Average 25,340 28.72% Pervious Area 62,884 71.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 22.3 150 0.0200 0.11 Sheet Flow, Landscape Sheet Flow Grass: Short n= 0.150 P2= 1.18" 0.8 50 0.0200 0.99 Shallow Concentrated Flow, Landscape Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 3.0 519 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 26.1 719 Total Subcatchment A3: Basin A3 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Type II 24-hr 100-yr 24-hr Rainfall=2.34" Runoff Area=88,224 sf Runoff Volume=0.210 af Runoff Depth=1.25" Flow Length=719' Slope=0.0200 '/' Tc=26.1 min CN=88 2.39 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 23HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment S1: Existing Roadways Runoff = 3.66 cfs @ 12.01 hrs, Volume= 0.192 af, Depth= 0.94" Routed to Pond P1 : Apex Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 100-yr, 24-hr Rainfall=2.34" Area (sf) CN Description 63,164 98 Paved roads w/curbs & sewers, HSG B 43,928 61 >75% Grass cover, Good, HSG B 107,092 83 Weighted Average 43,928 41.02% Pervious Area 63,164 58.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Asphalt Sheet Flow Smooth surfaces n= 0.011 P2= 1.18" 4.3 745 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 1.2 311 0.0037 4.16 5.11 Pipe Channel, Pipe 1 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.010 PVC, smooth interior 0.8 267 0.0057 5.30 9.37 Pipe Channel, Pipe 2 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 9.1 1,473 Total Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 24HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Subcatchment S1: Existing Roadways Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)4 3 2 1 0 Type II 24-hr 100-yr 24-hr Rainfall=2.34" Runoff Area=107,092 sf Runoff Volume=0.192 af Runoff Depth=0.94" Flow Length=1,473' Tc=9.1 min CN=83 3.66 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 25HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment S2: S27th East 1/2 Runoff = 1.29 cfs @ 11.96 hrs, Volume= 0.065 af, Depth= 1.90" Routed to Pond P2 : S27th Blvd Pond (Temporary) Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 100-yr, 24-hr Rainfall=2.34" Area (sf) CN Description 16,843 98 Paved roads w/curbs & sewers, HSG B 964 61 >75% Grass cover, Good, HSG B 17,807 96 Weighted Average 964 5.41% Pervious Area 16,843 94.59% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Smooth surfaces n= 0.011 P2= 1.18" 2.9 500 0.0200 2.87 Shallow Concentrated Flow, Pavement Paved Kv= 20.3 fps 5.7 650 Total Subcatchment S2: S27th East 1/2 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Type II 24-hr 100-yr 24-hr Rainfall=2.34" Runoff Area=17,807 sf Runoff Volume=0.065 af Runoff Depth=1.90" Flow Length=650' Slope=0.0200 '/' Tc=5.7 min CN=96 1.29 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 26HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth > 0.55" for 100-yr, 24-hr event Inflow = 1.00 cfs @ 13.80 hrs, Volume= 0.423 af Primary = 1.00 cfs @ 13.80 hrs, Volume= 0.423 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Inflow Area=9.153 ac 1.00 cfs1.00 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 27HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P1: Apex Pond Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth = 1.09" for 100-yr, 24-hr event Inflow = 7.28 cfs @ 12.00 hrs, Volume= 0.828 af Outflow = 1.00 cfs @ 13.80 hrs, Volume= 0.423 af, Atten= 86%, Lag= 107.6 min Primary = 1.00 cfs @ 13.80 hrs, Volume= 0.423 af Routed to Pond A0 : Outfall A (Apex Pond Outfall) Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,943.95' @ 13.80 hrs Surf.Area= 9,514 sf Storage= 20,837 cf Plug-Flow detention time= 325.7 min calculated for 0.423 af (51% of inflow) Center-of-Mass det. time= 197.1 min ( 1,059.7 - 862.6 ) Volume Invert Avail.Storage Storage Description #1 4,940.00' 21,250 cf Custom Stage Data (Conic) Listed below Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,940.00 3,863 0.0 0 0 3,863 4,941.00 3,863 40.0 1,545 1,545 4,083 4,941.50 4,656 100.0 2,127 3,672 4,885 4,942.00 5,548 100.0 2,548 6,220 5,786 4,942.50 6,493 100.0 3,007 9,227 6,741 4,943.00 7,486 100.0 3,492 12,719 7,745 4,943.50 8,525 100.0 4,000 16,719 8,796 4,944.00 9,613 100.0 4,532 21,250 9,897 Device Routing Invert Outlet Devices #1 Primary 4,943.60'1.5' long x 0.40' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 3.6' Crest Height Primary OutFlow Max=1.00 cfs @ 13.80 hrs HW=4,943.95' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 1.00 cfs @ 1.97 fps) Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 28HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond P1: Apex Pond Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=9.153 ac Peak Elev=4,943.95' Storage=20,837 cf 7.28 cfs 1.00 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 29HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P2: S27th Blvd Pond (Temporary) Inflow Area = 0.409 ac, 94.59% Impervious, Inflow Depth = 1.90" for 100-yr, 24-hr event Inflow = 1.29 cfs @ 11.96 hrs, Volume= 0.065 af Outflow = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,946.91' @ 24.33 hrs Surf.Area= 0.052 ac Storage= 0.065 af Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 4,945.00' 0.070 af 10.00'W x 75.00'L x 2.00'H Prismatoid Z=4.0 Pond P2: S27th Blvd Pond (Temporary) Inflow Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Inflow Area=0.409 ac Peak Elev=4,946.91' Storage=0.065 af 1.29 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 30HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond R1: Blvd Infiltrator Inflow Area = 1.177 ac, 65.00% Impervious, Inflow Depth = 1.05" for 100-yr, 24-hr event Inflow = 2.44 cfs @ 11.95 hrs, Volume= 0.103 af Outflow = 2.19 cfs @ 11.97 hrs, Volume= 0.083 af, Atten= 10%, Lag= 1.7 min Primary = 2.19 cfs @ 11.97 hrs, Volume= 0.083 af Routed to Pond P1 : Apex Pond Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,950.50' @ 11.97 hrs Surf.Area= 600 sf Storage= 1,200 cf Plug-Flow detention time= 125.5 min calculated for 0.083 af (80% of inflow) Center-of-Mass det. time= 40.2 min ( 875.5 - 835.4 ) Volume Invert Avail.Storage Storage Description #1 4,947.00' 1,200 cf Custom Stage Data (Conic) Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,947.00 600 0.0 0 0 600 4,948.00 600 40.0 240 240 687 4,949.00 600 40.0 240 480 774 4,949.50 600 40.0 120 600 817 4,950.00 600 100.0 300 900 860 4,950.50 600 100.0 300 1,200 904 Device Routing Invert Outlet Devices #1 Primary 4,950.00'2.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=2.19 cfs @ 11.97 hrs HW=4,950.50' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 2.19 cfs @ 2.31 fps) Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 31HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond R1: Blvd Infiltrator Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Inflow Area=1.177 ac Peak Elev=4,950.50' Storage=1,200 cf 2.44 cfs 2.19 cfs GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 1HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 2-yr, 24-hr Type II 24-hr Default 24.00 1 1.18 2 2 5-yr, 24-hr Type II 24-hr Default 24.00 1 1.49 2 3 10-yr, 24-hr Type II 24-hr Default 24.00 1 1.70 2 4 25-yr, 24-hr Type II 24-hr Default 24.00 1 1.96 2 5 50-yr, 24-hr Type II 24-hr Default 24.00 1 2.15 2 6 100-yr, 24-hr Type II 24-hr Default 24.00 1 2.34 2 7 Water Quality Type II 24-hr Default 24.00 1 0.50 2 Type II 24-hr 2-yr, 24-hr Rainfall=1.18"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 2HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 15.84% Impervious, Inflow Depth = 0.08" for 2-yr, 24-hr event Inflow = 0.70 cfs @ 12.03 hrs, Volume= 0.060 af Primary = 0.70 cfs @ 12.03 hrs, Volume= 0.060 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=9.153 ac 0.70 cfs0.70 cfs Type II 24-hr 5-yr, 24-hr Rainfall=1.49"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 3HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 15.84% Impervious, Inflow Depth = 0.17" for 5-yr, 24-hr event Inflow = 1.38 cfs @ 12.02 hrs, Volume= 0.130 af Primary = 1.38 cfs @ 12.02 hrs, Volume= 0.130 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Inflow Area=9.153 ac 1.38 cfs1.38 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 4HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 15.84% Impervious, Inflow Depth = 0.25" for 10-yr, 24-hr event Inflow = 1.91 cfs @ 12.02 hrs, Volume= 0.190 af Primary = 1.91 cfs @ 12.02 hrs, Volume= 0.190 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Inflow Area=9.153 ac 1.91 cfs1.91 cfs Type II 24-hr 25-yr, 24-hr Rainfall=1.96"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 5HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 15.84% Impervious, Inflow Depth = 0.36" for 25-yr, 24-hr event Inflow = 2.64 cfs @ 12.02 hrs, Volume= 0.276 af Primary = 2.64 cfs @ 12.02 hrs, Volume= 0.276 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Inflow Area=9.153 ac 2.64 cfs2.64 cfs Type II 24-hr 50-yr, 24-hr Rainfall=2.15"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 6HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 15.84% Impervious, Inflow Depth = 0.45" for 50-yr, 24-hr event Inflow = 3.22 cfs @ 12.02 hrs, Volume= 0.347 af Primary = 3.22 cfs @ 12.02 hrs, Volume= 0.347 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)3 2 1 0 Inflow Area=9.153 ac 3.22 cfs3.22 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 7HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 15.84% Impervious, Inflow Depth = 0.55" for 100-yr, 24-hr event Inflow = 3.84 cfs @ 12.02 hrs, Volume= 0.423 af Primary = 3.84 cfs @ 12.02 hrs, Volume= 0.423 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)4 3 2 1 0 Inflow Area=9.153 ac 3.84 cfs3.84 cfs Type II 24-hr Water Quality Rainfall=0.50"GC3 Pre-Development Conditions Printed 11/20/2025Prepared by WWC Engineering Page 8HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 15.84% Impervious, Inflow Depth = 0.00" for Water Quality event Inflow = 0.00 cfs @ 23.99 hrs, Volume= 0.001 af Primary = 0.00 cfs @ 23.99 hrs, Volume= 0.001 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-30.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 302928272625242322212019181716151413121110987654321Flow (cfs)0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0 0 Inflow Area=9.153 ac 0.00 cfs0.00 cfs GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 1HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 2-yr, 24-hr Type II 24-hr Default 24.00 1 1.18 2 2 5-yr, 24-hr Type II 24-hr Default 24.00 1 1.49 2 3 10-yr, 24-hr Type II 24-hr Default 24.00 1 1.70 2 4 25-yr, 24-hr Type II 24-hr Default 24.00 1 1.96 2 5 50-yr, 24-hr Type II 24-hr Default 24.00 1 2.15 2 6 100-yr, 24-hr Type II 24-hr Default 24.00 1 2.34 2 7 Water Quality Type II 24-hr Default 24.00 1 0.50 2 Type II 24-hr 2-yr, 24-hr Rainfall=1.18"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 2HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P1: Apex Pond Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth = 0.27" for 2-yr, 24-hr event Inflow = 1.12 cfs @ 12.06 hrs, Volume= 0.205 af Outflow = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routed to Pond A0 : Outfall A (Apex Pond Outfall) Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,942.45' @ 29.58 hrs Surf.Area= 6,395 sf Storage= 8,915 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 4,940.00' 21,250 cf Custom Stage Data (Conic) Listed below Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,940.00 3,863 0.0 0 0 3,863 4,941.00 3,863 40.0 1,545 1,545 4,083 4,941.50 4,656 100.0 2,127 3,672 4,885 4,942.00 5,548 100.0 2,548 6,220 5,786 4,942.50 6,493 100.0 3,007 9,227 6,741 4,943.00 7,486 100.0 3,492 12,719 7,745 4,943.50 8,525 100.0 4,000 16,719 8,796 4,944.00 9,613 100.0 4,532 21,250 9,897 Device Routing Invert Outlet Devices #1 Primary 4,943.60'1.5' long x 0.40' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 3.6' Crest Height Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=4,940.00' (Free Discharge) 1=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr 2-yr, 24-hr Rainfall=1.18"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 3HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond P1: Apex Pond Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Inflow Area=9.153 ac Peak Elev=4,942.45' Storage=8,915 cf 1.12 cfs 0.00 cfs Type II 24-hr 5-yr, 24-hr Rainfall=1.49"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 4HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P1: Apex Pond Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth = 0.46" for 5-yr, 24-hr event Inflow = 2.12 cfs @ 12.05 hrs, Volume= 0.350 af Outflow = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routed to Pond A0 : Outfall A (Apex Pond Outfall) Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,943.32' @ 30.49 hrs Surf.Area= 8,144 sf Storage= 15,251 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 4,940.00' 21,250 cf Custom Stage Data (Conic) Listed below Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,940.00 3,863 0.0 0 0 3,863 4,941.00 3,863 40.0 1,545 1,545 4,083 4,941.50 4,656 100.0 2,127 3,672 4,885 4,942.00 5,548 100.0 2,548 6,220 5,786 4,942.50 6,493 100.0 3,007 9,227 6,741 4,943.00 7,486 100.0 3,492 12,719 7,745 4,943.50 8,525 100.0 4,000 16,719 8,796 4,944.00 9,613 100.0 4,532 21,250 9,897 Device Routing Invert Outlet Devices #1 Primary 4,943.60'1.5' long x 0.40' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 3.6' Crest Height Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=4,940.00' (Free Discharge) 1=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr 5-yr, 24-hr Rainfall=1.49"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 5HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond P1: Apex Pond Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Inflow Area=9.153 ac Peak Elev=4,943.32' Storage=15,251 cf 2.12 cfs 0.00 cfs Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 6HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P1: Apex Pond Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth = 0.60" for 10-yr, 24-hr event Inflow = 3.13 cfs @ 12.05 hrs, Volume= 0.459 af Outflow = 0.12 cfs @ 24.02 hrs, Volume= 0.055 af, Atten= 96%, Lag= 718.3 min Primary = 0.12 cfs @ 24.02 hrs, Volume= 0.055 af Routed to Pond A0 : Outfall A (Apex Pond Outfall) Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,943.69' @ 24.02 hrs Surf.Area= 8,929 sf Storage= 18,403 cf Plug-Flow detention time= 725.4 min calculated for 0.055 af (12% of inflow) Center-of-Mass det. time= 556.8 min ( 1,439.7 - 882.9 ) Volume Invert Avail.Storage Storage Description #1 4,940.00' 21,250 cf Custom Stage Data (Conic) Listed below Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,940.00 3,863 0.0 0 0 3,863 4,941.00 3,863 40.0 1,545 1,545 4,083 4,941.50 4,656 100.0 2,127 3,672 4,885 4,942.00 5,548 100.0 2,548 6,220 5,786 4,942.50 6,493 100.0 3,007 9,227 6,741 4,943.00 7,486 100.0 3,492 12,719 7,745 4,943.50 8,525 100.0 4,000 16,719 8,796 4,944.00 9,613 100.0 4,532 21,250 9,897 Device Routing Invert Outlet Devices #1 Primary 4,943.60'1.5' long x 0.40' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 3.6' Crest Height Primary OutFlow Max=0.12 cfs @ 24.02 hrs HW=4,943.69' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 0.12 cfs @ 0.96 fps) Type II 24-hr 10-yr, 24-hr Rainfall=1.70"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 7HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond P1: Apex Pond Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)3 2 1 0 Inflow Area=9.153 ac Peak Elev=4,943.69' Storage=18,403 cf 3.13 cfs 0.12 cfs Type II 24-hr 25-yr, 24-hr Rainfall=1.96"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 8HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P1: Apex Pond Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth = 0.79" for 25-yr, 24-hr event Inflow = 4.98 cfs @ 12.02 hrs, Volume= 0.603 af Outflow = 0.30 cfs @ 16.58 hrs, Volume= 0.199 af, Atten= 94%, Lag= 273.4 min Primary = 0.30 cfs @ 16.58 hrs, Volume= 0.199 af Routed to Pond A0 : Outfall A (Apex Pond Outfall) Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,943.76' @ 16.58 hrs Surf.Area= 9,085 sf Storage= 19,050 cf Plug-Flow detention time= 473.2 min calculated for 0.199 af (33% of inflow) Center-of-Mass det. time= 325.4 min ( 1,198.5 - 873.1 ) Volume Invert Avail.Storage Storage Description #1 4,940.00' 21,250 cf Custom Stage Data (Conic) Listed below Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,940.00 3,863 0.0 0 0 3,863 4,941.00 3,863 40.0 1,545 1,545 4,083 4,941.50 4,656 100.0 2,127 3,672 4,885 4,942.00 5,548 100.0 2,548 6,220 5,786 4,942.50 6,493 100.0 3,007 9,227 6,741 4,943.00 7,486 100.0 3,492 12,719 7,745 4,943.50 8,525 100.0 4,000 16,719 8,796 4,944.00 9,613 100.0 4,532 21,250 9,897 Device Routing Invert Outlet Devices #1 Primary 4,943.60'1.5' long x 0.40' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 3.6' Crest Height Primary OutFlow Max=0.30 cfs @ 16.58 hrs HW=4,943.76' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 0.30 cfs @ 1.30 fps) Type II 24-hr 25-yr, 24-hr Rainfall=1.96"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 9HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond P1: Apex Pond Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)5 4 3 2 1 0 Inflow Area=9.153 ac Peak Elev=4,943.76' Storage=19,050 cf 4.98 cfs 0.30 cfs Type II 24-hr 50-yr, 24-hr Rainfall=2.15"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 10HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P1: Apex Pond Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth = 0.94" for 50-yr, 24-hr event Inflow = 6.15 cfs @ 12.01 hrs, Volume= 0.714 af Outflow = 0.56 cfs @ 14.64 hrs, Volume= 0.309 af, Atten= 91%, Lag= 157.6 min Primary = 0.56 cfs @ 14.64 hrs, Volume= 0.309 af Routed to Pond A0 : Outfall A (Apex Pond Outfall) Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,943.84' @ 14.64 hrs Surf.Area= 9,262 sf Storage= 19,789 cf Plug-Flow detention time= 382.1 min calculated for 0.309 af (43% of inflow) Center-of-Mass det. time= 245.1 min ( 1,112.5 - 867.4 ) Volume Invert Avail.Storage Storage Description #1 4,940.00' 21,250 cf Custom Stage Data (Conic) Listed below Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,940.00 3,863 0.0 0 0 3,863 4,941.00 3,863 40.0 1,545 1,545 4,083 4,941.50 4,656 100.0 2,127 3,672 4,885 4,942.00 5,548 100.0 2,548 6,220 5,786 4,942.50 6,493 100.0 3,007 9,227 6,741 4,943.00 7,486 100.0 3,492 12,719 7,745 4,943.50 8,525 100.0 4,000 16,719 8,796 4,944.00 9,613 100.0 4,532 21,250 9,897 Device Routing Invert Outlet Devices #1 Primary 4,943.60'1.5' long x 0.40' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 3.6' Crest Height Primary OutFlow Max=0.56 cfs @ 14.64 hrs HW=4,943.84' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 0.56 cfs @ 1.61 fps) Type II 24-hr 50-yr, 24-hr Rainfall=2.15"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 11HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond P1: Apex Pond Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)6 5 4 3 2 1 0 Inflow Area=9.153 ac Peak Elev=4,943.84' Storage=19,789 cf 6.15 cfs 0.56 cfs Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 12HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P1: Apex Pond Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth = 1.09" for 100-yr, 24-hr event Inflow = 7.28 cfs @ 12.00 hrs, Volume= 0.828 af Outflow = 1.00 cfs @ 13.80 hrs, Volume= 0.423 af, Atten= 86%, Lag= 107.6 min Primary = 1.00 cfs @ 13.80 hrs, Volume= 0.423 af Routed to Pond A0 : Outfall A (Apex Pond Outfall) Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,943.95' @ 13.80 hrs Surf.Area= 9,514 sf Storage= 20,837 cf Plug-Flow detention time= 325.7 min calculated for 0.423 af (51% of inflow) Center-of-Mass det. time= 197.1 min ( 1,059.7 - 862.6 ) Volume Invert Avail.Storage Storage Description #1 4,940.00' 21,250 cf Custom Stage Data (Conic) Listed below Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,940.00 3,863 0.0 0 0 3,863 4,941.00 3,863 40.0 1,545 1,545 4,083 4,941.50 4,656 100.0 2,127 3,672 4,885 4,942.00 5,548 100.0 2,548 6,220 5,786 4,942.50 6,493 100.0 3,007 9,227 6,741 4,943.00 7,486 100.0 3,492 12,719 7,745 4,943.50 8,525 100.0 4,000 16,719 8,796 4,944.00 9,613 100.0 4,532 21,250 9,897 Device Routing Invert Outlet Devices #1 Primary 4,943.60'1.5' long x 0.40' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 3.6' Crest Height Primary OutFlow Max=1.00 cfs @ 13.80 hrs HW=4,943.95' (Free Discharge) 1=Sharp-Crested Rectangular Weir (Weir Controls 1.00 cfs @ 1.97 fps) Type II 24-hr 100-yr, 24-hr Rainfall=2.34"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 13HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond P1: Apex Pond Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=9.153 ac Peak Elev=4,943.95' Storage=20,837 cf 7.28 cfs 1.00 cfs Type II 24-hr Water Quality Rainfall=0.50"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 14HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond P1: Apex Pond Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth = 0.02" for Water Quality event Inflow = 0.02 cfs @ 12.96 hrs, Volume= 0.013 af Outflow = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min Primary = 0.00 cfs @ 1.00 hrs, Volume= 0.000 af Routed to Pond A0 : Outfall A (Apex Pond Outfall) Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Peak Elev= 4,940.37' @ 27.37 hrs Surf.Area= 3,863 sf Storage= 575 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 4,940.00' 21,250 cf Custom Stage Data (Conic) Listed below Elevation Surf.Area Voids Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) (sq-ft) 4,940.00 3,863 0.0 0 0 3,863 4,941.00 3,863 40.0 1,545 1,545 4,083 4,941.50 4,656 100.0 2,127 3,672 4,885 4,942.00 5,548 100.0 2,548 6,220 5,786 4,942.50 6,493 100.0 3,007 9,227 6,741 4,943.00 7,486 100.0 3,492 12,719 7,745 4,943.50 8,525 100.0 4,000 16,719 8,796 4,944.00 9,613 100.0 4,532 21,250 9,897 Device Routing Invert Outlet Devices #1 Primary 4,943.60'1.5' long x 0.40' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 3.6' Crest Height Primary OutFlow Max=0.00 cfs @ 1.00 hrs HW=4,940.00' (Free Discharge) 1=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) Type II 24-hr Water Quality Rainfall=0.50"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 15HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Pond P1: Apex Pond Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Inflow Area=9.153 ac Peak Elev=4,940.37' Storage=575 cf 0.02 cfs 0.00 cfs GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 1HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing (selected events) Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 25-yr, 24-hr Type II 24-hr Default 24.00 1 1.96 2 Type II 24-hr 25-yr, 24-hr Rainfall=1.96"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 2HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A1: Basin A1 Runoff = 1.62 cfs @ 12.63 hrs, Volume= 0.254 af, Depth= 0.87" Routed to Pond P1 : Apex Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 25-yr, 24-hr Rainfall=1.96" Area (sf) CN Description 130,298 85 1/8 acre lots, 65% imp, HSG B 21,801 98 Paved roads w/curbs & sewers, HSG B 152,099 87 Weighted Average 45,604 29.98% Pervious Area 106,495 70.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 56.1 150 0.0020 0.04 Sheet Flow, Landscape Sheet Flow Grass: Short n= 0.150 P2= 1.18" 2.8 478 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 58.9 628 Total Subcatchment A1: Basin A1 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Type II 24-hr 25-yr 24-hr Rainfall=1.96" Runoff Area=152,099 sf Runoff Volume=0.254 af Runoff Depth=0.87" Flow Length=628' Tc=58.9 min CN=87 1.62 cfs Type II 24-hr 25-yr, 24-hr Rainfall=1.96"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 3HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A2: Basin A2 Runoff = 1.78 cfs @ 11.95 hrs, Volume= 0.075 af, Depth= 0.77" Routed to Pond R1 : Rain Garden 1 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 25-yr, 24-hr Rainfall=1.96" Area (sf) CN Description 51,274 85 1/8 acre lots, 65% imp, HSG B 17,946 35.00% Pervious Area 33,328 65.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Asphalt Sheet Flow Smooth surfaces n= 0.011 P2= 1.18" 0.7 117 0.0200 2.87 Shallow Concentrated Flow, Shallow Concentrated Paved Kv= 20.3 fps 3.5 267 Total Subcatchment A2: Basin A2 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Type II 24-hr 25-yr 24-hr Rainfall=1.96" Runoff Area=51,274 sf Runoff Volume=0.075 af Runoff Depth=0.77" Flow Length=267' Slope=0.0200 '/' Tc=3.5 min CN=85 1.78 cfs Type II 24-hr 25-yr, 24-hr Rainfall=1.96"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 4HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment A3: Basin A3 Runoff = 1.78 cfs @ 12.21 hrs, Volume= 0.157 af, Depth= 0.93" Routed to Pond P1 : Apex Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 25-yr, 24-hr Rainfall=1.96" Area (sf) CN Description 67,849 85 1/8 acre lots, 65% imp, HSG B 15,823 98 Paved parking, HSG B 4,552 90 1/8 acre lots, 65% imp, HSG C 88,224 88 Weighted Average 25,340 28.72% Pervious Area 62,884 71.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 22.3 150 0.0200 0.11 Sheet Flow, Landscape Sheet Flow Grass: Short n= 0.150 P2= 1.18" 0.8 50 0.0200 0.99 Shallow Concentrated Flow, Landscape Shallow Concentrated Flow Short Grass Pasture Kv= 7.0 fps 3.0 519 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 26.1 719 Total Subcatchment A3: Basin A3 Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)1 0 Type II 24-hr 25-yr 24-hr Rainfall=1.96" Runoff Area=88,224 sf Runoff Volume=0.157 af Runoff Depth=0.93" Flow Length=719' Slope=0.0200 '/' Tc=26.1 min CN=88 1.78 cfs Type II 24-hr 25-yr, 24-hr Rainfall=1.96"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 5HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment S1: Existing Roadways Runoff = 2.58 cfs @ 12.02 hrs, Volume= 0.137 af, Depth= 0.67" Routed to Pond P1 : Apex Pond Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Type II 24-hr 25-yr, 24-hr Rainfall=1.96" Area (sf) CN Description 63,164 98 Paved roads w/curbs & sewers, HSG B 43,928 61 >75% Grass cover, Good, HSG B 107,092 83 Weighted Average 43,928 41.02% Pervious Area 63,164 58.98% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.8 150 0.0200 0.91 Sheet Flow, Asphalt Sheet Flow Smooth surfaces n= 0.011 P2= 1.18" 4.3 745 0.0200 2.87 Shallow Concentrated Flow, Asphalt Shallow Concentrated Flow Paved Kv= 20.3 fps 1.2 311 0.0037 4.16 5.11 Pipe Channel, Pipe 1 15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31' n= 0.010 PVC, smooth interior 0.8 267 0.0057 5.30 9.37 Pipe Channel, Pipe 2 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.011 Concrete pipe, straight & clean 9.1 1,473 Total Type II 24-hr 25-yr, 24-hr Rainfall=1.96"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 6HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Subcatchment S1: Existing Roadways Runoff Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)2 1 0 Type II 24-hr 25-yr 24-hr Rainfall=1.96" Runoff Area=107,092 sf Runoff Volume=0.137 af Runoff Depth=0.67" Flow Length=1,473' Tc=9.1 min CN=83 2.58 cfs Type II 24-hr 25-yr, 24-hr Rainfall=1.96"GC3 Post-Development Printed 11/20/2025Prepared by WWC Engineering Page 7HydroCAD® 10.20-5c s/n 04342 © 2023 HydroCAD Software Solutions LLC Summary for Pond A0: Outfall A (Apex Pond Outfall) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 9.153 ac, 66.69% Impervious, Inflow Depth > 0.26" for 25-yr, 24-hr event Inflow = 0.30 cfs @ 16.58 hrs, Volume= 0.199 af Primary = 0.30 cfs @ 16.58 hrs, Volume= 0.199 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 1.00-40.00 hrs, dt= 0.01 hrs Pond A0: Outfall A (Apex Pond Outfall) Inflow Primary Hydrograph Time (hours) 40393837363534333231302928272625242322212019181716151413121110987654321Flow (cfs)0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=9.153 ac 0.30 cfs0.30 cfs Existing PipeInflow Q(25) (cfs)Pipe Size Pipe Material Pipe Slope Pipe Capacity (cfs)A36.3818"PVC0.38%7.01,2,12,16,17,18AF15.9118"RCP2.00%23.118C, 18D, 18E, Ex Pond 2F212.621"PVC0.60%13.21,2,12,16,17,18A, 18B, 18C, 18D, 18E, Ex Pond 2F413.921"PVC0.50%17.41,2,12,16,17,18A, 18B, 18C, 18D, 18E, 18F, 18G, Ex Pond 2F51.4821"PVC0.50%17.4Apex Pond OutfallSummary of post-development flow rates and pipe capacities.Existing Pipe Pipe Capacity (cfs)Inflow Q(25) (cfs)Notes: A37.07.53F123.110.87F213.213.64F417.413.64F517.40.30Summary of pipes to be upsized to accommodate increased flows from development.Updated Pipe Updated Pipe SizeUpdated Capacity (cfs)Inflow Q(25)(cfs)Available Capacity (cfs)A321"10.57.533.0F224"18.813.645.2BasinRunoff Q(25) (cfs)A11.62A21.78A31.78S12.58Apex Pond Outfall0.3010.9720.68120.49160.97170.86Ex Pond 22.77Summary of Gran Cielo Phase 2 Subdivision Stormwater Pipe Capacity, Gran Cielo Phase 2 Stormwater Report (2021) Appendix H.3. See Appendix E.2 for exhibits.NotesContributing basinsContributing basinsGC Phase 3 (Appendix D.4)GC Phase 2 (Appendix H.3)S1 includes Basins 17, 18B, 18E,18F, 18GA1 includes Basins 18C, A8DBasins A2 and A3 break up Basin 18ABold indicates updated or new valuesValues in red text indicate insufficently sized conveyance pipes1,2,12,16,17, A2, A31,2,12,16, A1, A2, A3, S11,2,12,16, Ex Pond 2, A1, A2, A3, S11,2,12,16, Ex Pond 2, A1, A2, A3, S1Apex Pond OutfallNo change to pipe material or slopePipe is assumed to be mistakenly labeled as 21". As-builts state 24" dia pipe installed. PIPE F2 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn. 1.486 A R2/3 S1/2 n Diameter,do (in) =24 Enter Value Diameter,do (ft) = 2 Units =1.486 n =0.013 RCP Slope, S (ft/ft)0.006 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00 0.10 0.90 0.06 0.90 0.07 0.87 0.07 0.02 0.1 37.8 18127.6 1.4 0.03 0.20 1.29 0.16 1.29 0.13 1.20 0.14 0.06 0.4 164.2 78812.2 2.2 0.08 0.30 1.59 0.30 1.59 0.19 1.43 0.21 0.13 0.9 382.3 183496.7 2.9 0.13 0.40 1.85 0.45 1.85 0.24 1.60 0.28 0.24 1.5 688.7 330575.2 3.4 0.18 0.50 2.09 0.61 2.09 0.29 1.73 0.35 0.37 2.4 1077.3 517096.1 3.9 0.24 0.60 2.32 0.79 2.32 0.34 1.83 0.43 0.52 3.4 1540.1 739248.1 4.3 0.29 0.70 2.53 0.98 2.53 0.39 1.91 0.51 0.70 4.6 2067.9 992578.3 4.7 0.34 0.80 2.74 1.17 2.74 0.43 1.96 0.60 0.91 5.9 2650.2 1272103.7 5.0 0.39 0.90 2.94 1.37 2.94 0.47 1.99 0.69 1.14 7.3 3275.8 1572368.2 5.3 0.44 1.00 3.14 1.57 3.14 0.50 2.00 0.79 1.39 8.8 3932.2 1887462.7 5.6 0.48 1.10 3.34 1.77 3.34 0.53 1.99 0.89 1.67 10.3 4606.3 2211015.1 5.8 0.52 1.20 3.54 1.97 3.54 0.56 1.96 1.00 1.97 11.8 5283.6 2536146.7 6.0 0.56 1.30 3.75 2.16 3.75 0.58 1.91 1.13 2.30 13.3 5948.7 2855385.4 6.1 0.58 1.40 3.96 2.35 3.96 0.59 1.83 1.28 2.66 14.7 6584.4 3160509.7 6.2 0.61 1.50 4.19 2.53 4.19 0.60 1.73 1.46 3.05 16.0 7171.4 3442270.3 6.3 0.62 1.60 4.43 2.69 4.43 0.61 1.60 1.68 3.50 17.1 7687.2 3689864.6 6.4 0.63 1.70 4.69 2.85 4.69 0.61 1.43 1.99 4.02 18.1 8103.8 3889835.8 6.3 0.63 1.80 5.00 2.98 5.00 0.60 1.20 2.48 4.69 18.7 8381.9 4023305.5 6.3 0.61 1.90 5.38 3.08 5.38 0.57 0.87 3.54 5.80 18.8 8450.4 4056212.3 6.1 0.58 2.00 6.28 3.14 6.28 0.50 0.00 17.5 7867.1 3776201.8 5.6 0.48 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 0.00 0.50 1.00 1.50 2.00 2.50 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE A3 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn. 1.486 A R2/3 S1/2 n Diameter,do (in) =21 Enter Value Diameter,do (ft) = 1.75 Units =1.486 n =0.013 RCP Slope, S (ft/ft)0.0038 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00 0.09 0.90 0.04 0.79 0.06 0.76 0.06 0.01 0.0 21.1 10104.4 1.0 0.02 0.18 1.29 0.13 1.13 0.11 1.05 0.12 0.04 0.2 91.5 43930.3 1.6 0.04 0.26 1.59 0.23 1.39 0.16 1.25 0.18 0.10 0.5 213.1 102282.0 2.1 0.07 0.35 1.85 0.34 1.62 0.21 1.40 0.24 0.17 0.9 383.9 184264.3 2.5 0.10 0.44 2.09 0.47 1.83 0.26 1.52 0.31 0.26 1.3 600.5 288232.0 2.8 0.13 0.53 2.32 0.61 2.03 0.30 1.60 0.38 0.37 1.9 858.5 412060.7 3.2 0.15 0.61 2.53 0.75 2.22 0.34 1.67 0.45 0.50 2.6 1152.6 553268.3 3.4 0.18 0.70 2.74 0.90 2.40 0.37 1.71 0.52 0.65 3.3 1477.2 709077.2 3.7 0.21 0.79 2.94 1.05 2.57 0.41 1.74 0.60 0.82 4.1 1825.9 876446.1 3.9 0.23 0.88 3.14 1.20 2.75 0.44 1.75 0.69 1.00 4.9 2191.8 1052081.4 4.1 0.26 0.96 3.34 1.36 2.92 0.46 1.74 0.78 1.20 5.7 2567.6 1232431.2 4.2 0.28 1.05 3.54 1.51 3.10 0.49 1.71 0.88 1.41 6.6 2945.1 1413661.2 4.4 0.29 1.14 3.75 1.66 3.28 0.50 1.67 0.99 1.65 7.4 3315.8 1591606.5 4.5 0.31 1.23 3.96 1.80 3.47 0.52 1.60 1.12 1.90 8.2 3670.2 1761684.4 4.5 0.32 1.31 4.19 1.94 3.67 0.53 1.52 1.28 2.19 8.9 3997.4 1918739.2 4.6 0.33 1.40 4.43 2.06 3.88 0.53 1.40 1.47 2.50 9.5 4284.9 2056749.5 4.6 0.33 1.49 4.69 2.18 4.11 0.53 1.25 1.74 2.88 10.1 4517.1 2168214.5 4.6 0.33 1.58 5.00 2.28 4.37 0.52 1.05 2.17 3.36 10.4 4672.1 2242611.2 4.6 0.32 1.66 5.38 2.36 4.71 0.50 0.76 3.09 4.15 10.5 4710.3 2260953.6 4.4 0.31 1.75 6.28 2.41 5.50 0.44 0.00 9.8 4385.2 2104874.3 4.1 0.26 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 0.00 0.50 1.00 1.50 2.00 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA Gran Cielo Phase 2 Subdivision Stormwater Pipe Capacity Summary Pipe Contributing Basin Inflow Q(25) (cfs)Pipe Size Pipe Material Pipe Slope Pipe Capacity (cfs) A1 1, 2, 12, 16, 17 3.97 15" PVC 0.38% 6.2 A2 18A 2.41 15" PVC 0.50% 7.1 A3 1, 2, 12, 16, 17, 18A 6.38 18" RCP 0.38% 7.0 B1 Ex. Pond 2 2.77 15" PVC 1.05% 10.3 B2 Ex. Pond 2 2.77 15" PVC 1.05% 10.3 B3 18D 1.45 15" PVC 0.50% 7.1 B4 18D, Ex. Pond 2 4.22 15" PVC 2.14% 14.7 B5 18D, 18E, Ex. Pond 2 4.58 15" PVC 1.90% 13.8 C1 6 1.84 15" PVC 0.50% 7.1 C2 6, 7 2.92 15" PVC 0.68% 8.3 C3 13B, 9 2.08 15" PVC 0.50% 7.1 C4 6, 7, 8, 9, 13A, 13B 9.25 18" PVC 1.63% 20.8 C5 6, 7, 8, 9, 13A, 13B, 13C 9.97 18" PVC 0.50% 11.5 C6 6, 7, 8, 9, 13A, 13B, 13C, 13D 10.66 18" PVC 3.23% 29.3 D1 13F 0.57 15" RCP 0.50% 4.9 D2 13F, 13E 3.46 15" PVC 0.50% 7.1 E1 Irrigation 3.00 15" PVC 1.50% 12.3 E2 Bennet Pond Outflow 3.09 15" PVC 2.50% 15.9 E3 Irrigation, Bennet Pond Outflow 6.09 15" PVC 0.50% 7.1 F1 18C, 18D, 18E, Ex. Pond 2 5.91 18" PVC 2.00% 23.1 F2 1, 2, 12, 16, 17, 18A, 18B, 18C, 18D, 18E, Ex. Pond 2 12.60 21" RCP 0.60% 13.2 F3 18F 0.74 15" RCP 0.50% 4.9 F4 1, 2, 12, 16, 17, 18A, 18B, 18C, 18D, 18E, 18F, 18G, Ex. Pond 2 13.90 21" PVC 0.50% 17.4 F5 Apex Pond Outflow 1.48 21" PVC 0.50% 17.4 G1 4 3.26 15" PVC 0.50% 7.1 G2 4, 5 5.35 15" PVC 1.58% 12.6 DA Q(25) (cfs) 1 0.97 2 0.68 4 3.26 5 2.09 6 1.84 7 1.08 8 2.74 9 1.22 12 0.49 16 0.97 17 0.86 18A 2.41 18B 0.31 18C 1.33 18D 1.45 18E 0.36 18F 0.74 18G 0.57 13A 1.52 13B 0.86 13C 0.72 13D 0.69 13E 2.90 13F 0.57 Ex. Pond 2 2.77 * this is the design outflow of existing pond 2 Irrigation 3 * this is the estimated irrigation flow rate Bennet 3.09 * this is the Bennet Pond Design Outflow Apex 1.48 * This is the Apex Pond design outflow APEX DRIVES. 29TH AVE S. 29TH AVE BENNETT BLVDS. 30TH AVE S. 31ST AVE SHEETMADISON ENGINEERING895 TECHNOLOGY BLVD, SUITE 203BOZEMAN, MT 59718(406) 586-0262 (406) 586-5740 FAXOF GRAN CIELO EXHIBITGRAN CIELO PHASE 2 SUBDIVISIONSTORM DRAINAGE PIPING & INLETSBOZEMAN, MT1 inch = 0 SCALE 100' 200'50'100'SD1.2 S. 28TH AVE S. 27TH AVE S. 29TH AVE BENNETT BLVDAPEX DRIVES. 30TH AVE S. 31ST AVE S. 28TH AVE CIELO WAYTIERRA LANES. 29TH AVE GRAF STREETCIELO WAYPHASE 1 DRAINAGE AREAS SEE SHEET SD1.0 S. 29TH AVE SHEETMADISON ENGINEERING895 TECHNOLOGY BLVD, SUITE 203BOZEMAN, MT 59718(406) 586-0262 (406) 586-5740 FAXOF GRAN CIELO EXHIBITGRAN CIELO PHASE 2 SUBDIVISIONSTORM DRAINAGE BASINSBOZEMAN, MT1 inch = 0 SCALE 200 feet 400'100'200'SD1.1 Page 1 of 6 Stormwater Facility Operation, Inspection and Maintenance Plan Gran Cielo Subdivision, Phase 3 Application Number: 25703 November 2025 Page 2 of 6 GRAN CIELO SUBDIVISION, PHASE 3 STORMWATER FACILITY OPERATION, INSPECTION, AND MAINTENANCE PLAN Please see the responses to the requirements outlined in the City of Bozeman Design Standards and Specifications Sec. 6.2.3. a) A description of the responsible party or entity for operation, inspection, and maintenance as well as replacement of storm drainage facilities and the legal mechanism for succession/assignment. Response: The party responsible for operation, inspection, and maintenance as well as replacement of storm drainage facilities will be the property owner. b) A list of contact names and contact information (phone number, e-mail address, mailing address). Response: Bozeman Haus, LLC Phone: TBD Email: TBD Mailing Address: TBD c) Site plan illustrating the storm drainage facility and system components. Response: The stormwater report included in this site plan submittal includes several exhibits which show the drainage facilities and system components. d) A detailed list of required maintenance and inspection activities, schedule, and frequency for the various system components. Response: A detailed summary of required maintenance and inspection activities, schedule, and frequency for the stormwater collection system and retention/infiltration facilities is outlined below: • Curb Inlets & Pipes: o Keep the curb inlets of the facility free of leaves, rocks, and other debris. Inspect the curb inlets every 3 months and after heavy rains that deliver 0.5 inches of rainfall. Clean sediment from curb inlets with a Vac Truck when sediment at the bottom of basin exceeds 6”. Operators need to be properly trained in catch basin maintenance. Maintain a log of the amount of sediment collected and the date of cleaning. Page 3 of 6 o Keep the stormwater drainage piping free of leaves, rocks, and other debris. Inspect the piping bi-annually. Clean sediment from stormwater drainage piping with a Jet/Vac Truck when sediment at the bottom of stormwater drainage piping exceeds 3”. Operators must be properly trained in catch basin maintenance. Maintain a log of the amount of sediment collected and the date of cleaning. o Owner to maintain and fund inspection and maintenance of curb inlets and storm water drainage piping. • Retention/Infiltration Basins: o The storm water retention basins are to be mowed regularly. During the summer months, mow approximately every two weeks. Unless visibly tainted, dispose of lawn clippings in the same manner as yard waste. Otherwise, bag and dispose of at sanitary landfill. o Remove sediment by hand with a flat bottom shovel during the summer months whenever sediment covers vegetation. Have the grass cut short in that particular location so that the bed can be made as level as possible. o Re-sod damaged or disturbed areas immediately, or use grass plugs from the adjacent up-slope area. o Inspect the facilities periodically, especially after heavy rains (preferably monthly and after each storm that delivers 0.5 inches of rainfall). o Inspect flow control outlet semi-annually and clean it when soil and vegetation buildup interfere with flow introduction. o See that litter and other debris are removed from retention basins and swales. o Owner to maintain and fund Operation and Maintenance of stormwater facilities. e) Stormwater Facility Inspection Form with exhibit illustrating maintenance inspection requirements (see Attachment E). Response: The Stormwater Facility Inspection Form is included at the end of this narrative. The stormwater report included in this Site Plan Submittal includes several exhibits which show the drainage facilities and system components. f) Expected design life and replacement schedule for each component of the facility. Response: The proposed stormwater system will include curb inlets, manholes, PVC storm drain piping, surface retention/infiltration basins, and pervious pavers. Assuming proper maintenance and installation, all facilities Page 4 of 6 are anticipated to last more than 75 years, unless maintenance inspections indicate a need for replacement sooner. g) Itemized cost estimates for recurring operation, inspection, and maintenance activities and planned facility replacement. Response: • Recurring Operation: The surface retention/infiltration basins and stormwater collection systems are passive systems that require minimal maintenance to ensure ongoing operation. • Inspection: o Curb Inlet and Storm Piping Inspection – This inspection is a visual inspection that will require very little time by the facility maintenance person. It is anticipated no cost will be incurred for this inspection. o Retention/Infiltration Basins – Inspection of surface ponds does not require any equipment and requires very little time. The visual inspection is not anticipated to incur any cost. o Pervious Pavers – The inspection of pervious pavers is minimal and only requires a visual inspection. This is not anticipated to incur any cost. • Maintenance Activities: o Curb Inlet and Storm Piping Maintenance – The required maintenance is completely dependent on the accumulation of sediment in the basin and piping. It is anticipated that Jat-Vac cleaning will be required once every 5 years to remove the sediment at an estimated cost of $750.00. o Retention/Infiltration Basins – Maintenance for the surface retention/infiltration basins will require regular mowing, removing debris, lawn clippings, and sediment, re-sodding damaged areas. o Pervious Pavers – In the event vacuum maintenance is required based on debris accumulation in joints the cost of a sweeper/vacuum truck is approximately $1,000.00/day. It is estimated the pavers will need to be cleaned once every 5 years. Page 5 of 6 h) A financial plan and funding mechanism for funding the recurring operation, inspection, and maintenance activities and planned facility replacement. The plan shall include sinking fund calculations considering estimated inflation over the life of the system components and a determination of the annual funding to be set-aside for operation, inspection, maintenance, and replacement needs. Response: As mentioned above, it is estimated that the cost for maintaining the curb inlets, piping and pavers will occur every 5 years, and will cost $1,750.00. It is estimated that the retention/infiltration basins will be mowed approximately 15 times per year. Each time the basin is mowed, it will cost approximately $120 per visit, totaling $1,800.00 per year for mowing services. The basin may need to be re-sodded in damaged areas approximately every 10 years, which is estimated to cost about $5000.00. Overall, the total average maintenance costs are estimated to be about $150.00 per year for the inlets and piping, $200 per year for the pervious pavers and about $2,300.00 per year for the retention/infiltration basin, totaling $2,650.00 per year for all stormwater facilities. Estimated Maintenance Cost Summary Facility Interval Cost per Occurrence Estimated Cost per Year Curb Inlet and Storm Piping (Jet Vac) 5 years $750.00 $150.00 Retention/Infiltration Basins (Mowing) Bi-weekly (Summer Only) $120.00 $1,800.00 Retention/Infiltration Basins (Re-Sod) 10 years $5,000.00 $500.00 Average Yearly Estimated Maintenance Cost $2,450.00 Funding for maintenance will be provided by the property owner. It is recommended the owner anticipates a conservative annual budget of Page 6 of 6 $3,000/year to provide funds for the anticipated maintenance. This accounts for actual anticipated cost and inflation. Gran Cielo Subdivision Groundwater Depth Summary Table Well 8/8/2017 8/25/2017 9/8/2017 10/2/2017 10/16/2017 10/30/2017 11/29/2017 12/29/2017 2/12/2018 4/11/2018 5/7/2018 5/14/2018 5/21/2018 5/29/2018 6/6/2018 6/11/2018 6/18/2018 6/27/2018 7/2/2018 7/13/2018 8/15/2018 #2 4.70 4.75 5.07 4.37 4.60 5.14 4.31 5.20 4.87 2.18 3.29 3.64 4.12 4.27 4.33 4.71 4.99 4.66 DNF DNF 5.57 #3 4.41 4.19 4.49 3.60 3.40 4.21 3.27 4.14 3.72 1.45 2.70 2.96 3.42 3.52 3.57 3.96 4.17 3.32 3.50 3.58 4.31 #5 2.27 2.60 2.82 1.66 2.07 2.65 2.02 2.58 2.18 3.98 1.87 1.98 2.24 2.22 2.28 2.52 2.56 2.15 2.22 2.43 2.54 #6 3.82 3.46 3.84 2.71 2.84 3.09 2.21 2.98 2.50 1.22 2.20 2.32 2.72 2.64 2.76 3.12 3.17 2.70 2.72 3.25 3.79 #8 1.50 3.61 3.39 3.07 3.69 4.49 3.97 4.63 4.29 1.70 2.92 3.27 3.57 3.74 4.11 4.14 4.02 3.29 3.47 3.50 3.18 #10 2.60 4.29 4.44 4.34 4.92 5.67 5.56 DNF DNF 2.51 3.36 3.85 4.10 4.38 4.47 4.88 4.92 4.86 3.55 3.55 4.89 #13 3.66 3.70 4.03 3.89 3.85 4.32 3.97 4.66 4.71 0.54 1.65 1.83 2.79 3.09 3.22 3.64 3.30 3.18 DNF DNF DNF #15 4.57 5.04 5.28 5.35 5.55 6.05 6.17 6.68 6.80 1.88 2.94 3.69 4.32 4.74 4.99 5.25 5.33 4.24 4.29 4.00 4.65 DNF Did Not Find Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 2 SITE LOCATION AND EXISTING CONDITIONS The project site is located on the northeast side of the existing Gran Cielo Subdivision. See Figure 1 for the site location. The project area is undeveloped and is currently being used for construction staging and storage. PROPOSED PROJECT The proposed residential/multi-family project will include the construction of four, four-story, buildings and a large, asphalt parking lot in between the buildings. All the buildings will be supported on standard shallow foundations (perimeter footings/frost walls and interior footings) and be underlain by at-grade slabs. No off-site improvements will be built as part of the project. All adjacent streets are already in- place with city water and sewer mains. See Figure 2 for a concept site plan. As we understand it, some of the asphalt parking lot areas may be covered by covered canopies. The canopy structures will bear on standard footings/columns. The stormwater drainage from the parking lot areas will be graded/routed to the existing detention pond area in the northwest corner of the site. Other site improvements will include building services (ie. water service, fire service, and sewer service) as well as a short, looped water main extension in the parking lot. The above description of the proposed project is based on previous correspondence with the Architect and Civil Engineer, along with a review of the concept site/civil plans for the project. PROJECT ASSUMPTIONS Provided below are some project assumptions: • Prior to the Gran Cielo Subdivision development work, the groundwater depths in the project area were higher, especially in the spring during seasonal high water. This is based on 2017- 2018 groundwater monitoring data compared to current data from 2022 that was collected on some of the neighboring properties to the east and south. Most likely, the groundwater table is below the top of the “target” sandy gravel during most of the year. As a result, there is little chance that groundwater will impact foundation excavation/earthwork and the deeper ground- water conditions should lead to better/firmer subgrade soils for parking lot construction. • If groundwater is found to be above the top of the sandy gravel during foundation excavation, we recommend dewatering and the possible need for an initial layer of fabric-covered, clean, crushed rock to get above the wetness. Both of these recommendations are detailed herein. • We expect stable subgrade conditions during parking lot construction. If some of the soils are overly moist, some drying may be required. We have provided a 24-inch thick pavement section design for stable subgrade conditions. If needed, a thicker section is included for soft subgrade. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 3 SUMMARY OF SITE CONDITIONS Provided below is a summary of the site conditions: • The project site and surrounding areas are underlain by shallow, native sandy gravel beginning at depths of 2.0 to 4.0 feet. The gravels extend for 10’s of feet and are the “target” foundation bearing material for all footings. • The native gravels are overlain by silt/clay and about 9 to 12 inches of organic topsoil. We expect the silt/clay will be in a moist, but stable condition for asphalt pavement construction. • Prior to the development of the Gran Cielo Subdivision, seasonal high groundwater levels in the general area rose to depths of 1.0 to 2.0 feet. Based on some groundwater monitoring that was conducted by AESI in the spring of 2022 on the neighboring Bennett property (to the southeast of the Block 14, Phase IV area), the high water levels were significantly lower in 2022 and rose to depths of 4.5 to 5.0 feet. Based on this limited data, it appears that post-development, ground- water levels are now lower as a result of “better drainage” around the underground utilities. SUMMARY OF GEOTECHNICAL ISSUES We do not expect any major issues at the site. Below are some potential issues and a summary of either why they are not issues or how they should be dealt with during construction: • High Groundwater: Since the buildings will be underlain by at-grade slabs, groundwater will not be an issue following foundation construction as well as long-term. Depending on the time of year, groundwater dewatering may be required during foundation excavation and underground utility installation. If the bottom of the foundation excavation is wet or contains groundwater, the first lift of building pad structural fill must consist of fabric-covered, clean crushed rock. • Soft Subgrade: We expect that the near surface, silt/clay will be in a moist, but stable condition during asphalt parking lot construction. If it is a little too moist and soft, it may need to be allowed to air dry or be scarified. Assuming stable conditions, we have provided a 24-inch design pavement section thickness (see below). If highly unstable/soft conditions are found to exist, we have provided a thicker pavement section option (33 inches thick) that incorporates a layer of Tensar TX-190L geogrid reinforcement for subgrade stabilization. SUMMARY OF RECOMMENDATIONS Provided below is a summary of the building and parking lot recommendations for the project: • The design soils bearing pressure for this project is 3,000 psf. This assumes that the buildings will be mass over-excavated down to native gravel per our recommendations. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 4 • The on-site soils are not corrosive to concrete. As a result, normal cement can be used for the foundation concrete. • All buildings shall be underlain by at-grade slabs (slab-on-grade) and be supported on shallow, conventional foundations consisting of perimeter footings/foundation walls and a dense array of interior, strip and spread footings. The buildings will not contain any crawl space areas. • The entire foundation footprint area of all buildings shall be mass over-excavated down to the native “target” sandy gravel (in a large, “bathtub” excavation) and a building pad section of granular structural fill shall be placed to build up to footing and interior slab grades. All footings must bear on native gravel or on structural fill that in turn is supported on the native gravel. • For the canopy structures in the parking lot area, all footings shall be individually excavated and bear on native sandy gravel or on granular structural fill that in turn is supported on the gravel. • The recommended granular structural fill material is import, 3”-minus sandy gravel. • All interior foundation wall backfill (under interior slabs) must consist of granular structural fill. For exterior wall backfill, native non-organic soils are be used. • The interior slab of the building shall be underlain by a minimum of 6 inches of 1”-minus clean, crushed rock that in turn bears on the thick section of building pad granular structural fill, which overlies “target” sandy gravel throughout the bottom of the mass over-excavation area. • The moisture protection provisions for the buildings shall include a 15-mil, heavy duty, vapor barrier under the interior slab and damp-proofing of the foundation walls per the IBC. Due to the slab-on-grade foundation configuration, no footing drains are required. Any elevator pits shall be underlain by a vapor barrier, be water-proofed per IBC, and contain a sump chamber. • The typical city standard under exterior concrete slabs is 3 inches (min.) of clean, crushed rock. We recommend thickening this crushed rock layer to 6 to 12 inches (depending on the location of the slab relative to the building) in order to improve the subgrade support and reduce the risk of frost heaving. For driveway/vehicle slabs, our recommendation for the slab support section is 6 inches of crushed rock and 12 inches of sub-base gravel over fabric-covered subgrade. • In 2019, AESI performed a soil corrosivity analysis for the Gran Cielo Subdivision to determine what requirements would be required for the corrosion protection of ductile iron water mains, water services, and fire services. As part of this work, we tested four samples of the shallow, sandy gravel soils. Based on the testing, none of the subdivision soils are highly corrosive and the use of special, zinc-coated DIP pipe is not needed. Due to the test results and the shallow gravel depths, polyethylene encasement is also not needed around water mains, water services, and fire services (since all piping will be installed and surrounded by the native sandy gravel). Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 5 • One of the major benefits of the building pad granular structural fill section is that all of the sub- slab plumbing trenches and excavation under the slab area will be in the 3”-minus gravel section materials. For plumbing trench backfill (above the pipe bedding), either the granular structural fill can be re-used (which will require placement in thin lifts and compaction) or 1”-minus, clean, crushed rock can be used (which is easier to place and compact in tight/confined areas). It is our recommendation that if crushed rock is used for trench backfill, it should be placed in lifts and be vibratory compacted. The use of crushed rock is viewed as a construction expediate to the Contractor and we do not believe a change order is warranted if the Contractor elects to use crushed rock in lieu of the excavated, 3”-minus sandy gravel. • We expect stable parking lot subgrade conditions in most (if not all) areas of the site. Where the subgrade soils are overly moist and softer, some level of subgrade drying and scarification may be needed. The design pavement section we recommend for stable subgrade conditions is: o 3” Asphalt o 6” Base Gravel o 15” Sub-Base Gravel o 315 lb. Woven Geotextile Fabric o Stable Subgrade (Dry, Hard, and Compacted) 24” Total Section Thickness • If some areas of the parking lot subgrade are too wet and soft to adequately dry out, then a thicker pavement section option with geogrid reinforcement may be needed. The section that is provided below is for unstable subgrade conditions: (Note: Most likely, this thicker pavement section recommendation will not be needed during construction.) o 3” Asphalt o 6” Base Gravel o 24” Sub-Base Gravel o Tensar TX-190L Geogrid o 8 oz. Non-Woven Geotextile Fabric o Soft Subgrade (Smooth and Rut-Free) 33” Total Section Thickness EXPLORATIONS, TESTING, AND SUBSURFACE CONDITIONS Subsurface Explorations No on-site test pits were conducted by AESI. All test pit work within the boundaries of the Gran Cielo Subdivision property were performed by HKM during their 2007 geotechnical investigation. See Figure 3 for a map showing all of HKM’s test pits. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 6 Over the years, AESI has dug test pits on many of the nearby properties, located to the west, east, and south. See Figure 1 for a map showing all of AESI’s area test pits. In addition to our nearby test pits, we have witnessed/inspected all of the foundation earthwork in the Gran Cielo Subdivision up to this point. As a result, we are very familiar with the soil conditions. Laboratory Testing No laboratory testing was conducted as part of this project. Note: As stated previously, AESI dug test pits and sampled/tested the Gran Cielo Subdivision soils as part of our subdivision-wide, soil corrosivity analysis in 2019. Soil Conditions The soil conditions throughout the Gran Cielo Subdivision area consist of about 9 to 12 inches of organic topsoil overlying a thin layer of sandy silt to sandy lean clay. In most locations, the silt/clay is slightly moist to moist and stiff to very stiff. Beginning at depths of 2.0 to 4.0 feet is the “clean” sandy gravel with scattered cobbles. The gravelly soils extend for 10’s of feet below ground surface and are defined as the “target” foundation bearing material for all footings. Groundwater Conditions Groundwater depths are assumed to range from 3.0 to 8.0 feet, depending on the location and the time of year. Most likely, groundwater levels stay below the top of the sandy gravel during much of the year. In some areas, seasonal high groundwater may rise to near or above the top of the gravels in the spring. GEOTECHNICAL ISSUES Given the site’s soil and groundwater conditions and the fact that the buildings will be underlain by at- grade slabs, this project has limited geotechnical issues. The only two, potential issues that we can foresee include: 1) high groundwater during foundation earthwork and 2) soft subgrade during parking lot construction. Each of these items is further described below. • High Groundwater During Foundation Excavation: There is a chance that groundwater will be near or above the top of the “target” sandy gravel during mass foundation over-excavation. If this is the situation, we first recommend that the excavation area be dewatered to below the top of the gravel. If some areas of the excavation contain wet gravel subgrade soils or shallow, standing groundwater, the first lift of granular structural fill must consist of fabric-covered, 1”- minus, clean, crushed rock (to get above the wetness before placing granular structural fill). Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 7 • Soft Subgrade During Parking Lot Construction: All of the subgrade soils under the parking lots will consist of native, non-organic silt/clay (following topsoil stripping). We expect slightly moist to moist and stiff to very stiff conditions in most (if not all) areas. If subgrade soils are overly moist and on the softer side, some level of drying and scarification may be required by the Earthwork Contractor to improve the stability of the subgrade soils. This work will take time and effort. If this condition occurs, it will be a requirement that the subgrade first try and be dried out. If the weather does not cooperate or if the soils are just too wet and soft, then the thicker, geogrid-reinforced pavement section option may need to be used in some areas of the site. We do expect the use of the thicker section will be widespread and it will likely not be needed at all. GENERAL CONSTRUCTION RECOMMENDATIONS Topsoil Stripping and Re-Use The site is blanketed by approximately 9 to 12 inches of black to dark brown, organic topsoil. All topsoil must be completely removed from within the building foundation footprint areas and from under all exterior concrete slab and asphalt pavement areas. The final site grading (in landscape areas) and the reclamation of disturbed construction areas are the only recommended uses of this material. Groundwater Dewatering Depending on the time of year, groundwater dewatering may be required for foundation excavation and water and sewer installations. If groundwater dewatering is needed, we recommend the installation of standard wellpoints/dewatering wells (which most utility contractors use) that lower the groundwater table well below the bottom of the excavation. Subgrade Scarification and Drying Depending on the time of year and the subgrade elevations (ie. cut depth), some areas of the parking lot subgrade soils may need to be dried and scarified. This will take time, effort, and good weather. Most likely, most of the subgrade soils will be slightly moist to moist and stiff to very stiff and not be an issue. Excavation and Re-Use of On-Site Soils The soils that will be excavated during foundation earthwork and site development will include topsoil, silt/clay, and sandy gravel. Provided below are the allowable re-uses of the on-site materials: • Organic topsoil materials shall only be used for final site grading in landscape areas. • The only allowable uses for native silt/clay are for site grading, embankment fill under parking lot areas, and exterior foundation wall backfill. Only the driest silt/clay that can be compacted to project specifications shall be re-used for wall backfill. As discussed in a later backfill section Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 8 of the report, we are recommending a thicker gravel/crushed rock section under exterior slabs that abut the foundation walls and lie in front of doorways and underlie patios/porches/decks. • For interior foundation wall backfill (under interior slabs), we recommend the exclusive use of imported, granular structural fill (3”-minus sandy gravel). No on-site soils shall be used for interior backfill. • The only locations where native sandy gravels will likely be encountered is at the bottom of the foundation excavation and in the utility trench excavations. STRUCTURAL DESIGN PARAMETERS AND CONSIDERATIONS Foundation Design All buildings will be underlain by an at-grade slab (slab-on-grade) with perimeter footings/frost walls as well as an array of interior footings (throughout the building area). No crawl space areas are planned. Seismic Design Factors A main requirement of the Structural Engineer’s seismic analysis will be a determination of the site class. Based on our on-site explorations and knowledge of the underlying geology, the site class for the project site will be Site Class D (as per criteria presented in the 2021 IBC). This site class designation is valid as long as our foundation recommendations are followed. To obtain site-specific seismic loading and response spectrum parameters, a web-based application from the USGS Earthquake Hazards Program can be used. The link to their web page is as follows: https://earthquake.usgs.gov/hazards/designmaps/. Upon entering this page, there are links to three third- party interfaces that can be used to obtain the seismic information. The user needs to enter the design code reference document, site soil classification, risk category, site latitude, and site longitude. Foundation Bearing Pressure (Shallow Foundation/Footings) As long as our shallow foundation support recommendations are followed (ie. mass exc.), the allowable bearing pressure for all perimeter, interior, and exterior footings and any other foundation component is 3,000 pounds per square foot (psf). Allowable bearing pressures from transient loading (due to wind or seismic forces) may be increased by 50 percent. We estimate that the above-referenced bearing pressure will result in total settlements of one inch or less, with only minor differential settlements. Note: For this project, we are recommending mass over-excavation under the entire building footprint area (down to native, “target” sandy gravel) and placement of a thick, building pad section of granular structural fill (back up to footing and slab grades). As a result, all footings will either bear on the native gravel or on compacted, granular structural fill that in turn bears on the native gravel. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 9 Lateral Earth Pressures All foundation walls that will be fixed at the top prior to the placement of backfill should be designed for an “at rest” equivalent fluid pressure of 60 pounds per cubic foot (pcf). Cantilevered retaining walls may be designed for a lower, “active” equivalent fluid pressure of 45 pcf, provided either some slight outward rotation of the wall is acceptable upon backfilling or the wall is constructed in such a way that accommodates the expected rotation. These “at rest” and “active” design values are only applicable for walls that will have backfill slopes of less than ten percent; and which will not be externally loaded by surface pressures applied above and/or behind the wall. Lateral forces from wind, earthquakes, and earth pressures on the opposite side of the structure will be resisted by passive earth pressure against the buried portion of the foundation wall and by friction at the bottom of the footing. Passive earth pressures in compacted, fine-grained backfill (silt/clay) should be assumed to have an equivalent fluid pressure of 280 pcf; while a coefficient of friction of 0.5 is estimated between cast-in-place concrete and the “target” sandy gravel (or granular structural fill that is placed to build back up to footing grade from the “target” gravel subgrade). Actual footing loads (not factored or allowable loads) should be used for calculating frictional resistance to sliding along the base of the footing. Please be aware that the friction coefficient has no built-in factor of safety; therefore, an appropriate safety factor should be selected and used in all subsequent calculations for each load case. The above-referenced, equivalent fluid pressures (for at rest, active, and passive conditions) assume that the wall will be backfilled with a suitable material that is compacted to an unyielding condition and it will lie above the groundwater table and/or be well drained; thereby, preventing the backfill from becoming saturated and the wall from experiencing hydrostatic pressure. Each of these design pressures is for static conditions and will need to be factored accordingly to represent seismic loading. We recommend that we be retained to evaluate lateral earth pressures for geometries and/or loading conditions that do not meet the previously mentioned criteria. Subgrade Reaction Modulus (under Slabs) As long as our interior slab support recommendations are followed (as presented later in the report), the subgrade reaction modulus (k) can be assumed to be 200 pounds/cubic inch (pci). This is a modified design value that uses the subgrade reaction modulus (k) of the native silt/cay and factors it (increases it) based on a minimum section thickness of imported gravel to be placed under the slab. This design value assumes the slab will be underlain by at least 18 inches of compacted gravel or crushed rock. Note: For this project, we are recommending a minimum 18-inch thick, gravel support section under the interior slab area that consists of an upper 6-inch section of clean crushed rock and a lower 12-inch section of granular structural fill. In all actuality (since we are also recommending mass over-excavation of the entire building area down to “target” gravel), the entire slab area will be underlain by a thick section of compacted, granular structural fill that in turn bears on native gravel. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 10 Interior Slab Thickness Given the multi-family, residential use of the buildings, we expect that the interior slab will be 4 inches thick (minimum). With that said, the structural design will dictate the slab thickness. Soil Corrosivity to Concrete According to Montana Department of Transportation (MDT) highway design standards, Type I-II cement is used when soil sulfate contents are less than 0.20%. However, if sulfate levels are between 0.20 and 2.00%, then Type V cement is used. Note: Over the years, we have tested several samples of Bozeman-area silt/clay for soil corrosivity. All sample results have come back as being non-corrosive to standard concrete. There is no reason to use Type V cement for the foundation concrete. Normal cement can be used. FOUNDATION RECOMMENDATIONS General A detailed illustration showing our earthwork, foundation bearing, slab support, and building moisture protection recommendations for an at-grade slab (slab-on-grade) configuration is included as Figure 5. Please refer to this figure during the review of the report. Note: Figure 5 shows mass over-excavation of the entire building footprint (down to native gravel) and a building pad of compacted, granular structural fill (back up to footing and slab grades). Foundation Design and Support • All buildings will be underlain by an at-grade slab (slab-on-grade) and they will contain no crawl space areas. • The building foundations will be designed as a shallow, conventional foundations consisting of perimeter footings/foundation walls along with interior and exterior footings. • Parking lot covered canopies will bear on standard, spread footings and columns/sono tubes. • The “target” foundation bearing material for all footings (including the canopy footings) is the “clean”, sandy gravel at depths of 2.0 to 4.0 feet. All footings must bear directly on the native gravel or on granular structural fill that in turn is supported on the native gravel. • The minimum depth of cover for frost protection of perimeter and exterior footings is four feet. This dimension is measured from bottom of footing up to the final grade of the ground surface. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 11 Foundation Excavation and Earthwork • We recommend mass over-excavation (“bathtub” excavation) of the entire building area down to the “target” sandy gravel. The excavation area shall extend a minimum of 5.0 feet beyond the outside edge of perimeter footings and must encapsulate all exterior footings (for roof over- hangs) on the outside of the foundation walls. This method of excavation will prevent having to excavate/over-excavate under all footings on an individual basis (in trench and pad excavations). • We recommend that a building pad section of imported, granular structural fill (3”-minus, sandy gravel) be placed throughout the building mass over-excavation area. The gravel fill material must extend from the “target” gravel surface up to the bottom of footing and slab grades. • All covered canopy footings must be excavated down to “target” gravel and either bear on the native gravel or on granular structural fill that in turn bears on the native gravel. • There is a chance that shallow groundwater conditions could be above the top of the “target” gravel, depending on the time of year (namely during the spring). This will require groundwater dewatering to lower the water level during excavation and before structural fill placement. • If the “target” gravel subgrade is wet or contains some areas of shallow standing water, then granular structural fill cannot be placed. Instead, the initial lift of gravel fill material will need to consist of 1”-minus, clean crushed rock. The crushed rock layer shall be vibratory compacted and covered with a layer of 8 oz. non-woven geotextile separator fabric (Mirafi 180N or equal) before placing the first lift of granular structural fill. • If the “target” gravel surface is dry, it must be vibratory compacted with a large roller to a dense and unyielding condition prior to pouring footings or placing granular structural fill. • If the “target” gravel surface is wet or contains shallow standing water, it must be track-packed with the excavator and static rolled with a roller prior to placing the initial crushed rock layer. Shallow Footings (Standard Foundation) • The “target” bearing material for all footings (incl. perimeter, interior, and exterior footings as well as canopy footings) is native sandy gravel that underlies the site at depths of 2.0 to 4.0 feet. None of the overlying soil materials (incl. topsoil, silt/clay or “dirty” gravel) shall be left in-place under any footings. The “target” gravel is identifiable based on its brown color, “clean” sandy composition, and abundant rounded gravels and cobbles. • All footings must bear directly on the “target” gravel (ie. “clean” sandy gravel) or on compacted granular structural that in turn is supported on the native gravel. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 12 • Depending on perimeter footing grades (and canopy footing grades) relative to the top of the native gravel, some footing areas may bear directly on “target” gravel, while others will need to be over-excavated down to gravel and built back up to footing grade with granular structural fill. • All of the interior footings located directly under the slab will need to bear on a thicker granular structural fill section that in turn is supported on the “target” gravel. Based on the mass over- excavation method, the entire area inside of the perimeter foundation walls will be in-filled with granular structural fill (back up to interior footing and slab grades) following the pouring of the perimeter foundation walls. • To minimize disturbance to the native gravel subgrade surface, the excavation should be dug with a smooth-edge foundation bucket. • Prior to pouring footings or placing granular structural fill, the native gravel subgrade shall be cleaned of loose spoil materials and re-compacted to a dense and unyielding condition with a smooth drum roller. Track packing of the gravel subgrade with the excavator (to smooth it out) prior to compaction with the roller works well. • In areas where the foundation will need to be over-excavated down to native gravel, the limits of the excavation will need to extend wide enough beyond the outside edge of footings such that enough compacted structural fill is placed to keep the footing load transfer in the structural fill materials down to the “target” gravel. • The required minimum width that the granular structural fill section must extend beyond the outside edge of footing is dependent on the structural fill thickness. The formula is as follows: Structural Fill Thickness / 2.0 = Min. Width of Structural Fill Beyond Edge of Footing. Here are some examples: For 2.0 feet of fill, the fill must extend 1.0-foot beyond the edge of footing; For 4.0 feet of fill, the fill must extend 2.0 feet beyond the edge of footing. To ensure the structural fill extends far enough beyond the outside edge of footing and can be properly compacted along the sides of the excavation, we recommend that the structural fill extend a minimum of 5.0 feet beyond footings in all areas. This distance will need to be increased for structural thicknesses greater than 10.0 feet (which will not occur on this project site). • All granular structural fill that is placed under footings must consist of either 3”-minus, sandy (pitrun) gravel or 1.5”-minus, crushed (roadmix) gravel. Specifications for these materials are provided in a later section of the report. We recommend 3”-minus gravel for the building pad. • The granular structural fill section should be placed in multiple lifts (depending on thickness of fill required and the size of the roller used) with each lift being vibratory compacted to a dense and unyielding condition. A large, smooth drum roller should be used wherever possible. Small, walk-behind sheepsfoot rollers and hand-held, jumping jack compactors should be used in narrow/confined excavations and along edges and in corners of the excavation. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 13 FOUNDATION WALL BACKFILL RECOMMENDATIONS Provided below are our general recommendations for interior and exterior foundation wall backfill. • For interior foundation wall backfill (under interior slab areas), all backfill material must consist exclusively of high quality, 3”-minus granular structural fill. This material is easy to compact and will minimize any settlement potential under the slab. All backfill must be placed in thin lifts and be vibratory compacted to a dense and unyielding condition. We do not recommend using any native silt/clay soils for any interior backfill. • Select native silt/clay soils can be used for exterior foundation wall backfill. These materials must be well compacted to prevent unwanted settlements, especially under exterior slab areas. Use only the driest material available. All backfill must be placed in lifts and be well compacted. • To prevent any exterior slab settlement or exterior slab frost heaving issues for those slabs that are adjacent to doorways and foundation walls, we are recommending a minimum 12-inch thick, clean crushed rock section under these slab areas. During construction, some consideration should be given (by the Contractor) to fully backfilling these relatively small areas (from the perimeter footing grade up to slab grade) under all “building-adjacent slabs” with granular structural fill or clean crushed rock. By doing so, all frost heaving risk would be removed. INTERIOR SLAB RECOMMENDATIONS Provided below are our recommendations for interior slab support: • All interior slabs shall be supported on a minimum, 18-inch thick, compacted gravel section consisting of 6 inches of clean crushed rock underlain by 12 inches of granular structural fill. • Since we are recommending mass over-excavation of the entire building area down to “target” gravel and the placement of a building pad section of granular structural fill, the sub-slab gravel section will be much thicker (ie. 4.0 to 6.0 feet) than the 18-inch (min.) thickness in all areas. MOISTURE AND SUBSURFACE DRAINAGE RECOMMENDATIONS Provided below are our moisture protection and subsurface drainage recommendations for at-grade slab (slab-on-grade) foundation configurations. Moisture Protection (At Grade Slabs) • A heavy-duty vapor barrier shall underlie the entire floor area of the interior slab (directly under the slab and above the clean crushed rock layer). The purpose of the barrier is to minimize the Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 14 upward migration of water vapor into the building. The vapor barrier that we exclusively recommend is a Stego 15-mil vapor barrier (which has a water vapor transmission rate of 0.006 or less as established by ASTM E 96). All seams, joints, and pipe penetrations in the vapor barrier shall be sealed with Stego wrap polyethylene tape. Also, the barrier should be secured and sealed along the perimeter foundation walls. • Perimeter frost walls around at-grade slab areas shall be damp-proofed (per the current code). • If the current code does not require damp-proofing, then damp-proofing of the foundation walls can be omitted. Subsurface Drainage (At-Grade Slabs) • For at-grade slab areas (set above exterior grades), no perimeter footing drains are required. Elevator Pits (Beneath At-Grade Slabs) • All elevator pits shall be underlain by a 15-mil vapor barrier. • We recommend that foundation walls of elevator pits be water-proofed (per the code). • A sump chamber shall be part of the bottom of the pit. EXTERIOR SLAB RECOMMENDATIONS Provided in Table 1 is our recommendations for the design section under the light-duty, exterior slabs (including standard pedestrian sidewalks away from the building foundation and next to streets). Table 1. Exterior Concrete Slab (Light-Duty) – Sidewalks Away From Building – Stable Subgrade COMPONENT COMPACTED THICKNESS (IN) Concrete Slab: 4 (min.) 1”-Minus Clean Crushed Rock: 6 Granular Structural Fill – 3”-Minus Gravel or 1.5”-Minus Roadmix: No 315 lb. Woven Geotextile Separation Fabric (Mirafi 600X or Equal): No Stable Subgrade Soils (Less Topsoil) or Embankment Fill: Compacted to 95% TOTAL SECTION THICKNESS: 6 + Slab Thickness Notes: 1) We recommend this section for std. pedestrian sidewalks away from the building foundation and next to streets. 2) We expect pedestrian slabs will be 4 inches thick (min.). 3) City of Bozeman specs call for 3 inches (min.) of crushed rock; we recommend increasing this to 6 inches. 4) The purpose of the 6-inch thick, crushed rock section is to provide better support under the slab. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 15 5) Stable subgrade is required for this section. 6) If unstable subgrade exists, the soils must first be scarified and attempted to be dried out. Provided in Table 2 is our recommendations for the design section under the medium-duty, exterior slabs (including pedestrian sidewalks next to the building foundation wall, slabs at all doorway entries, and “patio/porch/deck area” slabs). Note: In the table below, we recommend a minimum of 12 inches of crushed rock under these slabs. A better recommendation to further lower the potential for frost heaving is to increase the gravel section under the “doorway and patio/porch/deck area slabs” to 24 inches (instead of 12 inches). This 24-inch sub-slab section can consist of 12 to 18 inches of granular structural fill topped by 6 to 12 inches of clean crushed rock. Note: To remove all frost heaving risk under slabs adjacent to doorways, strong consideration should be given to fully backfilling these relatively small slab areas with granular structural fill and/or clean crushed rock from footing grade up to bottom of slab. Table 2. Exterior Concrete Slab (Medium-Duty) – Sidewalks Next To Building – Stable Subgrade COMPONENT COMPACTED THICKNESS (IN) Concrete Slab: 4 (min.) 1”-Minus Clean Crushed Rock: 12 (See Below for Recommendations) Granular Structural Fill – 3”-Minus Gravel or 1.5”-Minus Roadmix: No 315 lb. Woven Geotextile Separation Fabric (Mirafi 600X or Equal): No Stable Subgrade Soils (Less Topsoil) or Embankment Fill: Compacted to 95% TOTAL SECTION THICKNESS: 12 + Slab Thickness Notes: 1) We recommend this section for pedestrian sidewalks next to the building, at doorways, and patios/porches/decks. 2) We expect pedestrian slabs will be 4 inches thick (min.). 3) City of Bozeman specs call for 3 inches (min.) of crushed rock; we recommend increasing this to 12 inches. 4) The purpose of the 12-inch thick, crushed rock section is to lower the frost heaving risk of the underlying silt/clay. 5) For doorway and patio/porch/deck slabs, we recommend the sub-slab gravel section be increased to 24 inches. 6) The purpose of the “expanded” 24-inch gravel section under slabs is to further reduce frost heaving potential. 7) Option 1: The 24-inch gravel section can consist of 6 inches of crushed rock and 18 inches of structural fill. 8) Option 2: The 24-inch gravel section can consist of 12 inches of crushed rock and 12 inches of structural fill. 9) Option 3: The 24-inch gravel section can consist entirely of 24 inches of crushed rock. 10) Stable subgrade is required for this section. 11) If unstable subgrade exists, the soils must first be scarified and attempted to be dried out. 12) An option for removing all frost heaving risk next to doors is to fully backfill under slabs w/ granular structural fill. 13) The granular backfill material shall extend from footing grade up to the bottom of the layer of clean crushed rock. 14) In lieu of granular structural fill, the doorway slabs can be fully backfilled with clean crushed rock. Provided in Table 3 (on the following page) is our recommendations for the design section under the heavy-duty, exterior slabs (including driveway aprons and sidewalks; as well as any other vehicle slabs). Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 16 Table 3. Exterior Concrete Slab (Heavy-Duty) – Driveway Aprons and Sidewalks – Stable Subgrade COMPONENT COMPACTED THICKNESS (IN) Concrete Slab: 6 (min.) 1”-Minus Clean Crushed Rock or 1.5”-Minus Base Course Gravel: 6 Sub-Base Course – 6”-Minus Uncrushed Sandy (Pitrun) Gravel: 12 315 lb. Woven Geotextile Separation Fabric (Mirafi 600X or Equal): Yes Stable Subgrade Soils (Less Topsoil) or Embankment Fill: Compacted to 95% TOTAL SECTION THICKNESS: 18 + Slab Thickness Notes: 1) We recommend this section for driveway aprons and sidewalks; and any other vehicle slabs. 2) We expect driveway apron/sidewalk slabs and vehicle slabs will be 6 inches thick (min.). 3) City of Bozeman specs call for 3 inches (min.) of crushed rock; we recommend increasing this to 6 inches. 4) The purpose of the 18-inch thick, total gravel section is to provide better support under the vehicle slabs. 5) We recommend a 24-inch total section thickness for slabs that will be subjected to vehicle/truck traffic loading. 6) If the slab thickness will be 8 inches instead of 6 inches, then reduce the crushed rock thickness from 6 to 4 inches. 7) Stable subgrade is required for this section. 8) If unstable subgrade exists, the soils must first be scarified and attempted to be dried out. SURFACE DRAINAGE RECOMMENDATIONS Final site grading next to the building must establish and promote positive surface water drainage away from the foundation footprint in all directions. Absolutely no water should be allowed to accumulate against or flow along any exposed wall (and thereby soak into the foundation wall backfill). Concrete or asphalt surfacing that abut the foundation should be designed with a minimum grade of two percent; while adjacent landscaped areas should have a slope of at least five percent within ten feet of the wall. Steeper side slopes than five percent (in landscape areas) are encouraged wherever possible. By doing this, any minor settlements in the foundation backfill should not negatively affect the positive drainage away from the building. To further reduce the potential for moisture infiltration along foundation walls, backfill materials should be placed in thin lifts and be well compacted, and in landscaped areas, they should be capped by four to six inches of topsoil. With the exception of the locations that will be surfaced by concrete or asphalt, finished grades (next to foundation walls) should be set no less than six inches below the top of the interior concrete slab or below the bottom of the sill plate for framed floor applications. FOUNDATION-RELATED FILL MATERIAL RECOMMENDATIONS Provided below (on the following page) are specifications for the fill materials that are recommended for use during foundation earthwork construction. These include on-site excavated soils, sandy (pitrun) gravel, crushed (road mix) gravel, and clean crushed rock. Fill placement and compaction criteria follow the specifications. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 17 Excavated Foundation Soils For more information on this, please refer to an earlier section of the report that is entitled “Excavation and Re-Use of On-Site Soils”. Sandy (pitrun) Gravel Sandy (pitrun) gravel is a granular structural fill alternative for placement under footings and slabs and behind walls. This material shall be a non-plastic, well-graded, mixture of clean, sand and gravel with 100 percent of its gravels/cobbles passing a three-inch screen and between 2 and 10 percent of its silt/clay particles (by weight) finer than the No. 200 sieve. It should meet all material and gradation specifications as presented in Section 02234 of the Montana Public Works Standard Specifications (MPWSS) for 3”-minus, uncrushed, sub-base course gravel. Note: We recommend the use of 3”-minus sandy gravel for all building pad structural fill material (from “target” gravel up to footing and slab grades) and for all interior foundation wall backfill. Crushed (road mix) Gravel Crushed (road mix) gravel is a granular structural fill alternative for placement under footings and slabs and behind walls. This material shall be a non-plastic, well-graded, mixture of clean, sand and gravel that is processed (crushed) such that 100 percent of its rock fragments pass a 1-1/2-inch screen and between 0 and 8 percent of its silt/clay particles (by weight) are finer than the No. 200 sieve. It should meet all material and gradation specifications as presented in Section 02235 of the MPWSS for 1-1/2”- minus, crushed, base course gravel. Clean Crushed Rock The primary uses for crushed rock include placement under concrete slabs and behind foundation and retaining walls for drainage-related purposes. Crushed rock shall be a clean assortment of angular fragments with 100 percent passing a one-inch screen and less than 1 percent (by weight) finer than the No. 100 sieve. This aggregate product needs to be manufactured by a crushing process and over 50 percent of its particles must have fractured faces. It is not acceptable to use rock containing abundant spherical particles for foundation-related applications. Fill Placement and Compaction All fill materials should be placed in uniform, horizontal lifts and compacted to an unyielding condition. This includes clean crushed rock, which can be readily compacted by vibratory means. In general, the maximum “loose lift thickness” for all fill materials (prior to compaction) should be limited to 12 inches for large, self-propelled rollers, 6 inches for remote-controlled, dual drum rollers and walk-behind, jumping jack compactors, and 4 inches for walk-behind vibratory plate compactors. The moisture Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 18 content of any material to be compacted should be within approximately two percent (+/-) of its optimum value for maximum compaction. Provided in Table 4 are compaction recommendations for general foundation applications. These are presented as a percentage of the maximum dry density of the fill material as defined in ASTM D-698. Table 4. Compaction Recommendations (Application vs. Percent Compaction) APPLICATION % COMPACTION Granular Structural Fill Under Footings and Slabs: 97 Interior Wall Backfill under Slabs (Granular Structural Fill): 97 Exterior Wall Backfill (Native Soil or Granular Structural Fill): 95 Clean Crushed Rock Under Footings/Slabs and Behind Walls: N/A (Vibration Required) Site Fill Around Building and Under Concrete and Pavement Areas: 95 UNDERGROUND UTILITIES General The underground “wet” utilities on this project (in addition storm drainage piping) will include building services (for water, fire, and sewer), a looped water main extension in the parking lot area, and the underslab piping/plumbing. Soil Corrosivity Potential for DIP Pipes For sure, the water main piping and building fire service lines will be ductile iron pipe (DIP). Depending on the size of the water services, they may be either be copper or DIP. Back in 2019, AESI performed a soil corrosivity analysis for the Gran Cielo Subdivision. This was required by the City at the time of subdivision development to determine if any of the on-site soils are corrosive to DIP pipes and if so, what level of corrosion protection would be recommended by DIPRA guidelines. Our work included four test pits throughout the area, soil sampling, and the lab testing of four samples of sandy gravel soils at depths of 6.0 feet (which is standard water main installation depth). Due to the shallow depth and thin soil layer configuration of the overlying silt/clay, these soils were not tested. What we learned through this analysis was that none of the area wide, sandy gravel soils (in Gran Cielo) are corrosive to DIP. The recommendations based on lab testing and DIPRA design guidance follows: • None of the soil conditions require the use of special, zinc-coated DIP pipe. • None of the soil conditions require the use of polyethylene encasement. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 19 Provided in Table 5 is the DIPRA scores and recommendations for each of the four soil samples that were collected and analyzed as part of the 2019 Gran Cielo soil corrosivity analysis. This table is an excerpt from the 2019 report, which was submitted to the City at that time. Table 5. Summary of DIPRA Scores and Recommendations from TP-1 – TP-4 TP # SAMPLE COMPOSITION TABLE 2 LIKELIHOOD SCORE TABLE 3 CONSEQUENCE SCORE TABLE 1 DIPRA RECOMMENDATION 1 Sandy Gravel 11 8 Standard Shop Coat 2 Sandy Gravel 11 8 Standard Shop Coat 3 Sandy Gravel 11 8 Standard Shop Coat 4 Sandy Gravel 13.5 8 Standard Shop Coat Notes: 1) TP-1 through TP-4 were dug in the SW, NW, NE, and SE corners of the property, respectively. 2) For likelihood scores of 1 to 20, the DIPRA recommendation is “as manufactured with shop coat”. 3) For likelihood scores of 21 to 40, the DIPRA recommendation is “V-Bio Enhanced Polyethylene Encasement”. 4) For likelihood scores of 41 to 50, the DIPRA recommendation is “V-Bio Poly Encsmnt w/ Zinc Coated Pipe”. 5) Based on the test results, use standard DIP pipe and no polyethylene encasement is required. DIP Corrosion Protection Recommendations for Gran Cielo Project Site (Block 14, Phase IV) Based on the test results and the shallow gravel conditions (2.0 to 4.0 feet) across the site, standard DIP pipe can be installed (ie. zinc-coated pipe is not needed) and no poly-wrapping is required for any of the water main, water service, and fire service improvements. Sub-Slab Plumbing Excavation and Trench Backfill Based on the mass over-excavation and building pad granular structural fill recommendation, all of the sub-slab materials that will be excavated during plumbing installation will be previously placed, 3”-minus granular structural fill or native sandy gravel. All of these gravelly materials can be readily re-used for trench backfill above the pipe bedding gravel. These materials must be placed in lifts and be compacted. As an option (for ease of backfill/compaction, faster backfilling, and convenience), the Contactor can choose to use 1”-minus, clean crushed rock for all of the plumbing trench backfill under the slab area. We still recommend that the crushed rock be placed in reasonable lifts and be vibratory compacted to a dense and unyielding condition. The use of crushed rock is not a requirement or a recommendation; it is simply an available option that the Contractor can choose to use. In our opinion, there should not be any change orders for the Contractor’s decision to use crushed rock. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 20 ASPHALT PAVEMENT SECTION RECOMMENDATIONS Pavement Section Design and Options All parking lot subgrade will consist of native silt/clay. In most areas, we expect the subgrade soils will be slightly moist to moist and consequently stiff to very stiff. As a result, we are recommending a design pavement section (Option 1) with a 24-inch total thickness for all pavement areas. This section requires dry, hard, compacted, and “stable” subgrade soils and is presented in Table 6. Some areas of the subgrade may be overly moist and softer. This may require that the subgrade be dried and scarified to improve the performance of subgrade and get it to a stable condition. Table 6. Pavement Section Design – Option 1 – All Parking Lot Areas – Stable Subgrade COMPONENT COMPACTED THICKNESS (IN) Asphalt Concrete: 3 Base Course – 1.5”-Minus Crushed (Roadmix) Gravel: 6 Sub-Base Course – 6”-Minus Uncrushed Sandy (Pitrun) Gravel: 15 315 lb. Woven Geotextile Fabric (Mirafi 600X or Approved Equal): Yes Stable Subgrade Soils (Less Topsoil): Hard and Compacted TOTAL SECTION THICKNESS: 24 Notes: 1) This is the standard pavement section design for all areas of the project site (parking lots and access drives). 2) The use of this design section requires that the subgrade soils are dry, hard, compacted, and stable. 3) To confirm the subgrade stability, all areas should be prepared and proof-rolled with a loaded gravel/water truck. 4) For stable silt/clay subgrade, place a 315 lb. woven fabric for subgrade separation. 5) At all seams, over-lap the fabric by 12 inches (min.). If areas of the parking lot subgrade are very moist to wet and unstable, then we have provided a second pavement section option (Option 2) for “unstable” subgrade. This section is presented in Table 7 and has a 33-inch total thickness. We do not expect that this option will be needed. Table 7. Pavement Section Design – Option 2 – All Parking Lot Areas – Unstable Subgrade COMPONENT COMPACTED THICKNESS (IN) Asphalt Concrete: 3 Base Course – 1.5”-Minus Crushed (Roadmix) Gravel: 6 Sub-Base Course – 6”-Minus Uncrushed Sandy (Pitrun) Gravel: 24 Tensar TriAx TX-190L Geogrid: Yes 8 oz. Non-Woven Geotextile Fabric (Mirafi 180N or Approved Equal): Yes Unstable Subgrade Soils (Less Topsoil): Smooth and Rut-Free TOTAL SECTION THICKNESS: 33 Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 21 Notes: 1) This heavy-duty pavement section is designed for unstable and soft soil conditions. 2) The non-woven fabric and geogrid layers shall be installed with 12-inch (min.) over-laps at the seams. 3) The geogrid layer shall be zip-tied together at the seams. 4) Depending on severity, the 24-inch sub-base gravel section may or may not be able to be placed in two lifts. 5) For firmer subgrade, the lower lift of sub-base should be 15 to 18 inches (+/-) if the conditions will allow. 6) For very soft subgrade, the entire 24-inch thick section should be placed/compacted in one single lift. 7) If the 24-inch sub-base will not bridge the soft soils, then the sub-base will need to be thickened (> 24 inches). Pavement Section Materials, Placement, and Compaction The sub-base and base course materials that comprise the granular parts of the pavement section shall consist of 6-inch minus uncrushed sandy (pitrun) gravel and 1-1/2-inch minus crushed (road mix) gravel, respectively. Both gravel courses shall meet the material and gradation specifications as presented in the MPWSS, Sections 02234 and 02235. All gravels shall be placed in loose lifts not exceeding 12 inches in thickness and be compacted to at least 95 percent of the material’s maximum dry density as defined in ASTM D-698. Asphalt pavement shall meet specifications in MPWSS Section 02510 and be compacted to a minimum of 93 percent of the Rice mix density. PRODUCTS Provided in Table 8 is a reference guide for all products (other than foundation-related fill material) that have been recommended within this report. Listed below is the name of the product, its intended use, and where it can be obtained. The manufacturer specification sheet for each of these products is attached at the end of the report. Note: Several notes are presented under the table that describe the recommended products, where they can be obtained, and where they can be used. Table 8. Product Reference Guide PRODUCT USE SOURCE PHONE Stego 15-mil Vapor Barrier Moisture Protection Under Slab MaCon Supply – Bozeman 551-4281 Mirafi 180N Non-Woven Fabric Wet Exc. & Soft Subgrade w/ Grid Multiple Sources – Bzn/Blgd N/A Mirafi 600X Woven Fabric Road Subgrade Separation Multiple Sources – Bzn/Blgd N/A Tensar TriAx TX-190L Geogrid Road Subgrade Stabilization Core & Main – Belgrade 388-5980 Notes: 1) Use Stego 15-mil vapor barrier only. There are no approved equals for this product. 2) Stego 15-mil vapor barrier has a water transmission rate that meets national standards for vapor barriers. 3) Stego 15-mil vapor barrier is a heavy-duty vapor barrier for placement under interior slabs and in crawl spaces. 4) Use Mirafi 180N non-woven fabric or an approved equal that meets or exceeds Mirafi 180N fabric specifications. 5) Approved equals for Mirafi 180N non-woven fabric are available from multiple sources in the Bzn/Blgd area. 6) Mirafi 180N is a medium-weight, 8 oz. non-woven fabric. 7) There are two potential uses for Mirafi 180N non-woven fabric on this project site. 8) Use 1: If the bottom of the foundation excavation is wet, an initial layer of clean crushed rock will be required. 9) Following vibratory compaction, the crushed rock layer must be covered with a layer of 8 oz. non-woven fabric. Final Geotechnical Report Blk. 14, Ph. IV, Gran Cielo Sub. – Bozeman, MT Project: 18-130.08 January 26, 2023 Allied Engineering Services, Inc. Page 23 enc: Figure 1 – Site Location w/ Area Test Pits Figure 2 – Concept Site Plan Figure 3 – Test Pit Locations w/ Depth to Native Gravel (Excerpt from 2007 HKM Geotech Rpt) Figure 4 – Table w/ Depth to Native Gravel (Excerpt from 2007 HKM Geotech Rpt) Figure 5 – Foundation Detail – At-Grade Slab Products (Vapor Barrier, Non-Woven Fabric, Woven Fabric, Geogrid) Limitations of your Geotechnical Report REFERENCES International Code Council, 2021, “International Building Code”. Montana Contractors’ Association, April 2021, “Montana Public Works Std. Specifications”, 7th Edition. P:\2018\18-130 Gran Cielo Sub.\Design\Geotech\Report – Block 14, Phase IV\Text\Block 14, Phase IV, Gran Cielo - Geotech Report.01.26.23 Figure 5 18-130 Jan. 2023 Gran Cielo Sub. (Block 14, Phase IV) Foundation Detail - At-Grade Slab Bozeman, Montana Damp-Proofing As Required (typ.) Foundation Wall (typ.)Approved Non-Woven Filter Fabric To Encase Bedding Gravel (typ.) Interior Floor Slab (typ.)Interior Steel Column (typ.)Interior Spread Footing (typ.) 6” Of 3/4" Minus Crushed Washed Gravel Hydraulically Connected To Sub-Drain or Existing Surface Drainage (typ.) Native Topsoil andRandom Surface Fill Imported 4-Inch Minus Sandy Pitrun Gravel Native Silt/ClayImported Flowable Fill Six Inch Diameter Sub-Drain Pipe (Graded To Drain To Sump Area) Concrete SidewalkLow Permeability Soils(Landscaped Area)LegendConcrete Wall and/or Footing Low Permeable Topsoil No Scale (Parts Of This Exhibit Have Been Exaggerated For Clarity) ALLIEDENGINEERING SERVICES, INC. Civil Engineering Geotechnical Engineering Land Surveying 32 Discovery Drive Bozeman, MT 59718 Phone: (406) 582-0221 Fax: (406) 582-5770 Slope Away @ 2% In All Concrete Or Pavement Areas (typ.) Footings 6’ max. depth below existing ground Native Topsoil 6” Minus Sandy (Pitrun) Gravel 4” Minus Sandy PitrunGravel (ie. Structural Fill)4’ max fill above existing ground 4' min. 4’ Max Fill Above Existing Ground 3” (min.) Thickness Will Vary Due To Depth Of Bedbrock Strata 6” (min.) 3” (min.) 8” (min.) 4.0’ (min.) 6” (min.) Of Rock Bedding To Be Placed Around Drain Piping (typ.) Under-Slab Rock Layer To Be Hydraulically Connected To Sub-Drain System By 3” Of Rock Or 2” Sch. 80 Piping Spaced On 10’ Centers (typ.) B H (Variable; Depends On Depth To Gravel) 18” (min.) 18” (min.) 6” (min.) 6” (min.) 1’ (min.) H = 3.5’ (Based On4.0’ Footing Depth And The Depth To Gravel In TP-4) H = 5.5’ (Based On4.0’ Footing Depth And The Depth To Gravel In TP-2) D D Woven Geotextile Filter Fabric (Amoco 2004)Vapor Barrier Under Slab (typ.) 9.5’ Deep (TP-2) 7.5’ Deep (TP-4) Non-Woven Filter Fabric To Encase 1-Inch Minus Rock 6” (min.) Rock Layer (typ.) Landscape Areas To Slope Away @ 5% (min.) Within 10’ Of Wall. Upper 4” - 6” Of Backfill Should Consist Of Low Permeable Topsoil. Note: Asphalt/Concrete Surfacing Placed Adjacent To Foundation Walls Shall Slope Away @ 2% (min.). 6” (min.) 6” (min.)4” PE Sub-Drain (typ.) Crawl Space Opening Must Be Properly Vented. Note: Elevation Difference Between The Top Back Of Curb And The Finished Floor Should Be Maximized. I Believe The Subdivision Covenants Call For A Minimum Separation Of 2.0’ And A Maximum Of 5.0’. Due To High Groundwater Concerns, An Elevation Difference Of More Than 2.0’ Is Recommended. This Should Be Thoroughly Considered On A Case By Case Basis. Please Refer To The Covenants For More Detail. Important Notes: The Three-Foot Wide (Min.) Over-Excavation From The Center Of The Footing Is Calculated Based On A 16-Inch Footing Width (B) And An Average Depth To Native Gravel (GD) Below The Footing Elevation Equal To Five Feet. If The Footing Is Substantially Wider Or The Depth To Gravel Substantially Deeper; The Width Of The Excavation Will Need To Be Increased. The Equation For Determining Excavation Width (EW) From The Center Of Footing Is: EW = (B + GD) / 2.0. If Caving (ie. Sloughing) Of The Excavation Side Walls Is A Problem; EW Will Need To Be Increased Accordingly. Since The Footings Are Supported On Structural Fill That Bears On Native Gravel; There Is No BenefitTo Increasing Footing Size Beyond What Is Shown On The Plans. If Groundwater Is Encountered In The Over-Excavation Above The Native Sandy Gravel Surface, We Recommend A Layer Of Crushed Rock First Be Used To Get Above The Groundwater Elevation. The Crushed Rock Should Be Placed In A Single Lift That Does Not Extend More Than Four Inches Above The Groundwater. After Placement, The Crushed Rock MUST Be Compacted By Vibratory Methods. Compactors That Are Suitable For Crushed Rock Include Walk-Behind Plate Compactors; Remote-Controlled Sheepsfoot Trench Rollers; And Self-Propelled Smooth Drum Rollers. Note: If Groundwater Is Not Encountered, The Use Of Crushed Rock Is Not Necessary. Compacted Structural Fill. Use Sandy Pitrun Gravel, Not Crushed Rock. Gravelly Materials Are Not Only Less Expensive But They Will Also Reduce The In-Flow Of Groundwater Into The Crawl Space In The Event That High Groundwater Exceeds The Crawl Space Elevation. Place The Pitun In Lifts (Six-Inch Thick Max. For Small Remote-Controlled Sheepsfoot Trench Rollers And Twelve-Inch Thick Max. For Self- Propelled Smooth Drum Rollers) And Compact To An Unyielding Condition. Note: A Material That Works Very Well For Foundation Structural FilI Is The 3” Minus Pitrun Gravel Product That Is Available From TMC In Belgrade. Pay Special Attention To Compaction Of Crushed Rock And Structural Fill Along Edges. Native Soils Could Be Soft. Rock / Fill Will Need To Be Compacted Into Side Of Excavation. Place Woven Geotextile Fabric Over The Crushed Rock. This Will Prevent Fines Migration Into The Rock After Placement Of The Structural Fill. 4” (max.) 3’ (min.) 3’ (min.) Interior Footing As A Precaution For Groundwater, Install 4” PE Slotted Drain Piping Along The Inside Of The Perimeter Footings And Grade To A Shallow Sump Chamber In The Crawl Space. If Water Becomes An Issue, Install Sump Pump And Discharge Out Of The Crawl Space. A Four-Inch Layer Of Crushed Rock Will Facilitate Rapid Drainage And Eliminate The Sight Of Standing Water. If A Vapor Barrier Is Placed Above The Crushed Rock; Ensure It Is A Material That Can Breathe (Not Polyethylene). All Interior Footings Shall Bear On Structural Fill. Finished Floor Elev. (At-Grade Slab) GD Existing Ground Surface Existing Ground 4” Slotted PE Pipe. Install Drain Piping Around Inside Perimeter Of Foundation. Piping Should Be Placed At Footing Grade Or Preferably Below The Top Of The Crushed Rock Fill (When Used). Connect Piping To Shallow Sump Chamber. If High Groundwater Is An Issue, A Pump Can Be Installed At A Later Time. 32” 48” Reviewed By: __________________ 4” To 6” (Min.) Thickness As Required 2.5’ 4’ (min.) Damp Proofing 4” Footing Drain (typ.) Min. Depth Of Cover For Frost Protection Min. Required Width Of Mass Over-Excavation Beyond Edge Of Footing 1.0’ - 17.0’ Depth To “Target” Bearing Material. Silt/Clay Below 2.5’ (+/-) Is Generally V. Moist To Wet. See TP Logs For Soil And Groundwater Conditions. 5.0’ - 13.5’ Depth To “Target” Bearing Material. Groundwater Depth Ranged From 6.0’ to 13.5’. Depending On Time Of Year, Groundwater May Be At Or Above The Sandy Gravel (“Target” Bearing Material). Therefore, Groundwater Dewatering May Be Needed. Dewatering Wells Are Recommended To Lower Water Below Gravel Surface. Strip, Remove, And Replace All Random Fill From Under The Entire Building Area, Including Under Interior House And Garage Slabs (typ.) Note: De-Watering Will Likely Not Be Required For Foundation Excavation. Based On Our Test Pits, All Evidence Suggests The Groundwater Table Stays Within The Sandy Gravel Most Of The Time. LSE, 1/25/23 Prior To The Placement Of Granular Structural Fill, The Site’s Shallow Groundwater Conditions May Require That An Initial Layer Of Clean Crushed Rock Be Placed And Compacted Up To A Height Of At Least 6 Inches Above The Level Of The Standing Water. Structural Fill: Use 4” Minus Sandy (pitrun) Gravel Due To Shallow, Seasonal High Groundwater Conditions, Footing And Crawl Space Depth Must Be Minimized Below The Existing Ground Surface. Bottom Of Footing Elevation Should Be Kept Within At Least 2.5’ To 3.0’ Of Existing Grades. As An Added Precaution Against High Groundwater In The Crawl Space (And Especially If Footing Depth Nears Or Exceeds 2.5’ To 3.0’ Below Existing Site Grades), We Strongly Encourage The Placement Of A 6” To 8” Layer Of Crushed Rock In The Crawl Space To Raise The Floor Elevation Up To The Top Of Footings. In The Event That Groundwater Ever Rises Above The Crushed Rock Layer, A Sump Chamber And Pump Can Easily Be Installed Later To Address The Problem. We Do Not Recommend Placing The Initial Layer Of Clean Crushed Rock In Standing Water Exceeding 10 Inches In Depth. Therefore, Depending On The Time Of Year, Some Groundwater De-Watering May Be Required During Foundation Earthwork. All Perimeter, Interior, And Exterior Footings Must Bear On A Minimum 2.0’ Thickness Of Granular Structural Fill That In Turn Is Supported On The Native Sandy Gravel (Which Is The ”Target” Foundation Bearing Material). Given The 4.5’ To 6.5’ Depth To Gravel, Along With The Anticipated Slab Grade, Perimeter Footings Will Likely Lie 2.0’ to 6.0’ Above The Top Of The “Target” Gravel. Mass Over-Excavate The Entire Foundation Footprint Area, Including All Exterior Footing Locations, Down To The “Target” Bearing Material (Native Sandy Gravel); Thereby, Completely Removing All Native Silt, Clay, Sand From Under The Building. Over-Dig The Excavation To The Minimum Width Dimensions As Shown On This Figure And As Stated In The Report. Important Note: Mass Over-Excavation Of The Foundation (As Illustrated By Option #2) Will Be Required If The Individual Footing Over-ExcavationsThat Are Depicted As Option #1 Will Not Stay “Open” Due To Trench Wall Collapse. Foundation Earthwork Notes: 1) Slab On Grade - Option “B” Consists Of Over-Excavating Under All Perimeter, Interior, And Exterior Footings.2) This Is Most Applicable Where The Building Is Underlain By Relatively Deep Gravels And The Foundation Contains Less Interior Footings.3) Where Present, All Random Surface Fill Material Must Be Fully Removed From Under The Entire Building Area Down To Native Soils. Foundation Excavation Recommendations: Due To The Large Number and Close Spacing Of Interior Footings (Many Of Which Are 13 To 14 Feet On-Center), We Recommend The Entire Foundation Footprint Area Of The Apartment Buildings Be Mass Over-Excavated Down to Native Sandy Gravel And Built Back Up To Footing And Slab Grades With Compacted Structural Fill. The Limits Of The Mass Excavation Must Encapsulate All Perimeter And Exterior Footings. Important Note: It Is Now COB Policy That The Foundation Earthwork Be Inspected And Certified By The Geotechnical Engineer. Suggestions: In Order To Reduce The Amount Of Required Structural Fill Under Footings And The Slab Area, The Finished Floor Elevation Should Be Minimized Above Existing Site Grades. Another Option To Reduce Fill Under Perimeter Footings Is To Use A 6’ Tall Foundation Wall. Foundation Backfill and Embankment Fill Granular Structural Fill(1.5”Minus Roadmix Gravel)Granular Structural Fill(1.5”Minus Roadmix Gravel)Sandy Gravel(”Target” Bearing Material) Low Permeable Topsoil Native Silt/Clay(Unsuitable Bearing Material) Native Silt Native Silt/Clay (Unsuitable Bearing Material) Native Topsoil Granular Structural Fill(4” Minus Sandy Gravel)Granular Structural Fill(1.5” Minus Roadmix Gravel)1” Minus CleanCrushed Rock Groundwater (on 4/19/16) Concrete Slab Exterior Foundation Wall Backfill Should Only Consist Of Excavated Soils That Are Not Overly Moist. It Must Be Placed In Multiple Lifts And Properly Compacted. Slab Grade Should Be Set Above Existing Grades. For The Mass Over- Excavation Option, There Is No Limit On Slab Height Above Existing Grades. H W = Footing Width + H; (5’ min.) All Foundation Fill Materials Should Be Placed In Uniform, Horizontal Lifts And Be Well Compacted. Granular Structural Fill Shall Be Compacted To A Dense, Unyielding Condition, While Clean Crushed Rock Or Lean Mix Concrete Must Be Compacted By Vibratory Means. In General, The “Loose” Thickness Of Each Lift Prior To Compaction Should Not Exceed 12 Inches For Large, Self- Propelled Rollers; 6 Inches For Remote-Controlled Trench Rollers And Walk-Behind Jumping Jack Compactors; And 4 Inches For Walk- Behind, Plate Compactors. Pay Special Attention To Compaction Of Structural Fill Along Edges And In Corners Of The Excavation. Place Crushed Rock As Fill Under Slab (6” min.) And Interior Wall Backfill Strip Topsoil Under Slab and Re-Compact The Subgrade Surface. Vapor Barrier Under Slab. Seal Barrier At Seams/Penetrations. Minimize New Fill Height For Settlement Reasons The Uppermost 6” Of Lean Mix Concrete Fill Can Be Replaced w/ Clean Crushed Rock For Easier Leveling Of Footing Grade. Bearing Pressure 4000 psf (max.) 6” (min.) Crushed Rock Layer Under Slab Areas (typ.) Important Note: To Stabilize The Trench Excavations And Minimize The Potential For Caving/Sloughing, Groundwater Dewatering May Be Required. Shallow Frost- Proof Foundation. Insulate As Per Applicable Codes. Interior Footing (typ.) Radon Mitigation System Should Be Considered Under Interior Slab. Important Note: If Foundation Construction Will Occur During The Cold/Winter Weather Season, The Contractor Shall Take All Necessary Precautions To Prevent The Earth- Work From Freezing And/Or From Being Contaminated With Snow. Note: At A Minimum, Use A Large, Smooth Drum Roller To Compact The Upper-Most Lift Of Structural Fill Under Footings And Slabs. Additional Thickness Of Gravel Building Pad As Req’d To Bear On “Target” Gravel. For Mass Excavation, Over-Excavation Width Beyond Perimeter Ftgs Is 5.0’ (typ.) See Fig. 6 For Over-Excavation Width Under Individual Ftg Excavations. Embankment Fill Can Be Used Below 18” Of Slab Grade. Note: No Topsoil Observed In On-Site Borings. Product Recommendation: A Stego 15-mil Vapor Barrier Is Recommended.Available From MaCon Supply In Bozeman. W = Footing Width + H; (5’ min.) Min. Width = 1/2(H); But Must Be 5’ Min. H H = 2’ Min. Important Note: If TP-3, A Clay Layer Was Observed Under The Native Sandy Gravel At A Depth Of 6.0’. It Is Recommended That All Footings Bear On A Minimum 24” Thickness Of Native Gravel Or Granular Structural Fill. This Should Be Confirmed With Test Pits Around The Perimeter Of The Building During Construction. Important Note: If The Trench Excavations Are Prone To Minor Caving, Their Width Will Have To Be Increased Accordingly To Prevent Slough From Underlying Or Being Mixed Into The Minimum Required Width Of Structural Fill. Given The 4.5’ To 6.0’ Depth To Native Sandy Gravel, We Do Not Expect That Most (If Any) Of The Perimeter Footings Will Bear Directly On Native Gravel. Most Likely, Footings Will Need To Be Supported On Structural Fill That In Turn Bears On Native Gravel (Similar To All Interior Footings). Excavation Alternative: In Lieu Of Only Excavating Footings, The Entire Foundation Footprint Area Of The Building Can Be Mass Over-Excavated Down To Native Sandy Gravel And Filled With Granular Structural Fill. Given The Gravel Depth, This Is Far Less Economical As Compared To The Above Recommendations. Prior To Granular Structural Fill Placement, The Excavated Gravel Surface (Under Entire Foundation Footprint Area) Must Be Vibratory Re-Compacted With A Large, Smooth Drum Roller In Order To Densify The Native Sandy Gravel. Due To Groundwater Depths Of 7.8’ To 9.8’, Wet Subgrade Conditions Should Not Be An Issue. Depending On Location, Groundwater Could Be At Or Above The Top Of Native Sandy Gravel During The Seasonal High Water Time Of Year. A Large, Smooth Drum Roller Must Be Used To Compact All Granular Structural Fill Whenever and Wherever Possible. Lean Mix Concrete(Flowable Fill)Embankment Fill(On-Site or Import Material) Embankment Fill (On-Site Or Import Material) 3000 psf (max.) B 3000 psf (max.) B Mass Excavate Under Entire Foundation Footprint Area Down To Native, Clean Sandy Gravel; Thereby Removing All Of The Silt/Clay Under The Interior Slab. All Footings Must Bear On Native Sandy Gravel Or On Compacted Granular Structural Fill That In Turn Is Supported On This “Target” Bearing Material. Shallow Frost-Proof Foundation Per IBC Is Also Acceptable. H H If Exc. Walls Slough, Widen Exc. To Ensure Min. Struct. Fill Width Beyond Edge Of Ftg. Bottom Of Exc. Measurement Centered Under The Footing. If Exc. Walls Slough, Widen Exc. To Ensure Min. Struct. Fill Width Beyond Edge Of Ftg. Bottom Of Exc. Measurement Centered Under The Footing. Min. Width = (B + H); But 5’ (min.) Crushed Rock Is Only Needed If Gravel Subgrade Is Wet Or Contains Standing Water. All Fill Material Placed Under Footings And Slabs To Consist Of Compacted Granular Structural Fill. No On-Site Soils Are To Be Used As Embankment Fill Under Slabs. Do Not Place Granular Structural Fill Materials Over Wet Subgrade Or In Shallow Standing Water. De-Water The Excavation If Required. If Bottom Of Excavation Is Wet, Place An Initial, Thin Layer Of Clean Crushed Rock Under The Structural Fill. The Crushed Rock Should Extend A Minimum Of About 4” Above The Wet Conditions. Vibratory Compact The Crushed Rock And Then Cover With A Medium-Weight, Non-Woven Fabric Prior To Structural Fill Placement. Overlap Seams Of Fabric By 12” Minimum. Over-Excavate Under All Perimeter, Interior, And Exterior Footings Down To Native, Clean Sandy Gravel; Thereby Removing All Silt/Clay Under Footings. All Footings Must Bear On Native Sandy Gravel Or On Compacted Granular Structural Fill That In Turn Is Supported On This “Target” Bearing Material. Embankment Fill Under Structural Fill Layer Must Be Compacted To Project Specifications. See Figure 7 For Recommendations For Foundation Fill Material Placement And Compaction. See Figure 7 For Recommendations For Ext. Foundation Wall Backfill Material And Compaction. For Basements, Additional SubsurfaceDrainage And Moisture Protection Recommendations Will Need To BeIncorporated That Are Not Shown On This Exhibit. See Report For More Details. No Scale (Parts Of This Exhibit Have Been Exaggerated For Clarity) Geotechnical Notes: 1) Figure 5 Illustrates A Slab-On-Grade Foundation With Perimeter Frost Walls And Footings. Interior Footings Are Shown Directly Under The Slab. All Footings Shall Bear On Native Sandy Gravel Or On Granular Structural Fill That In Turn Is Supported On The “Target” Gravel. We Recommend A “Bathtub” Excavation (Down To Gravel) And Gran. Struct. Fill Bldg Pad (Up To Ftg/Slab Grades). Granular Structural Under Footings And Slabs Can Consist Of4”-Minus Sandy Pitrun Gravel Or 1.5”-Minus Roadmix Gravel. Based On Test Pits, Depth To “Target” Bearing Material Is 4’ To 5’ On Downhill Side And 3’ On Uphill Side Of The Lot. Legend Random Fill (Unsuitable Bearing Material) Random Fill (Unsuitable Bearing Material) Low Permeable Topsoil Granular Structural Fill(4”-Minus Sandy Gravel) Granular Structural Fill (*) 1” Minus CleanCrushed Rock 1” Minus Clean Crushed Rock 1” Minus CleanCrushed RockExisting Grade (Ground Surface) Native Topsoil Topsoil or Asphalt/GravelSurfacing Materials Native Topsoil Floor Joist Exterior Foundation Backfill Native Sandy Gravel (“Target” Bearing Material) Native “Dirty” Sandy Gravel(Unsuitable Bearing Material) Native Topsoil Interior Wall Backfill (3”-Minus Sandy Gravel Granular Structural Fill) “Target” Bearing Material Is The Glacial Till. It Is Identifiable Based On Its Clean Sandy Composition, Abundance Of 6”-Minus, Sub-Rounded Gravels, And Dense Configuration. It Looks Like “Clean Pitrun Gravel” w/ Large Cobbles And Boulders. All Footings Shall Bear On A Minimum Of 1’ Of Granular Structural Fill That In Turn Bears On “Target” Glacial Till (typ). Additional Structural Fill Thickness Will Be Required Under Some Footings In Order To Reach “Target” Bearing Material. Recompact Subgrade Prior To Fill Placement (typ). All Foundation Fill Materials Should Be Placed In Uniform, Horizontal Lifts And Be Well Compacted. Granular Structural Fill, Embankment Fill, And Wall Backfill Shall Be Compacted To A Dense, Unyielding Condition, While Clean Crushed Rock Must Be Compacted By Vibratory Means. In General, The “Loose” Thickness Of Each Lift Prior To Compaction Should Not Exceed 12 Inches For Large, Self-Propelled Rollers; 6 Inches For Remote-Controlled Trench Rollers And Walk-Behind Jumping Jack Compactors; And 4 Inches For Walk-Behind, Plate Compactors. Pay Special Attention To Compaction Of Fill Materials Along Edges And In Corners Of The Excavation; And Along Foundation Walls. Daylight Footing And Sub-Slab Drains (typ.) See Figures 8 And 9 For Note On Exterior Foundation Wall Backfill. Granular Structural Fill Should Be Used For Interior Wall Backfill Under Slabs. See Figures 8 And 9 For Note On Foundation Fill Material Placement And Compaction. All Excavated Soils Can Be Re-Used For Exterior Wall Backfill Or Embankment Fill Provided They Are Not Organic Or Overly Moist. All Fill Must Be Placed In Thin, Level Lifts And Properly Compacted. H = 1’ or 2’ (Depending On Ftg Width) H = 1.0’ (min.) H H = 1.0’ (min.) 15-mil Vapor Barrier Under Slab (Above Rock Layer). Seal Barrier At Seams, Penetrations, And Footings. Vapor Barrier Not Typ. Under Garage Slabs. Note: Due To Unheated/Non-Insulated Buildings, Consider Insulating Under Interior Slabs To Minimize Frost Heaving Potential Of Silt/Clay. (*) Granular Structural Fill Can Consist Of 3”-Minus Sandy (Pitrun) Gravel Or 1.5”-Minus Crushed (Roadmix) Gravel Note: Groundwater Depths Are Expected To Be Below The Top Of “Target” Sandy Gravel Most Of The Year. During Spring, Seasonal High Water May Rise Near Or Above The Gravel. Note: Depending On Time Of Year, Groundwater Levels Could Be Near Or Above The Top Of Native Sandy Gravel. 4’ (min.) For Frost Protection No Ftg Drains Req’d Strip Topsoil And Bench Subgrade Level Prior To Placing Fill (typ.) About 6” Of Dirty Gravel Overlies The Clean Gravel.It Is Important To Vibratory Re-Compact The Excavated “Target” Gravel Subgrade Surface Prior To Pouring Ftgs Or Placing Struct. Fill. Where Possible, Enlarge The Excavation To Allow For Use Of Large, Smooth Drum Roller. Product Recommendation: A Stego 15-mil Vapor Barrier Is Recommended. Perimeter Footing Drain To Wrap Around The Exterior Of Home (typ.) Over-Excavate Under All Perimeter, Interior, And Exterior Footings Such That They Bear On A Minimum Of 1’ Of Compacted Granular Structural Fill That In Turn Bears On “Target” Glacial Till. Min. Width Is B+H, But It Shall Not Be Less Than 5’. Use Light-Weight Fabric Around Footing Drains (typ.). Over-Excavation Width Must Be Centered On The Footings (typ.) More Than 1.0’ Of Structural Fill Is Expected (typ.) Min. Width = (B + H); But Shall Be 5.0’ (min.) This Is A Bottom Of Exc. Dimension. Assumes No Sloughing Of Exc. Side Walls. Min. Width = (B + H); But Shall Be 5.0’ (min.) This Is A Bottom Of Exc. Dimension. Assumes No Sloughing Of Exc. Side Walls. A Large, Smooth Drum Roller Should Be Used To Vibratory Compact Subgrade Soils And Granular Structural Fill Wherever Possible. Concrete Slab The Excavated Gravel Surface (Under All Footings) Must Consist Of Dense, Clean, Native Sandy Gravel. Use A Smooth Foundation Bucket To Prevent Unnecessary Disturbance To The Native Gravel Subgrade. Do Not Stop Excavation In Lowermost Silt/Clay, Which Does Contain Some Scattered Gravels. The Silt/Clay w/ Gravels (Which Looks Like A “Dirty Gravel”) Does Not Constitute The Clean, Native Sandy Gravel (“Target” Bearing Material). Vibratory Re-Compact Subgrade Surface Whenever Possible. Re-Compact Subgrade Prior To Fill Placement. Additional Structural Fill Thickness As Required. For Strip Footings With Width Of 2.0’ Or Less, Min. Structural Fill Thickness (H) Is 1.0’. For Larger Pad Footings With Width Of 3.0’ To 6.0’, Min. Structural Fill Thickness (H) Is 2.0’. Exterior Wall Backfill Can Consist Of Any Non-Organic Soil. Suggest Removing Cobbles Over 6” Directly Next To Walls. Strip Topsoil/Surfacing Material And Cut To A Min. Depth Of 18 Inches Below Bottom Of Slab Grade. For Easier Compaction, Consider Using Only High Quality Granular Material Or Clean Crushed Rock For Interior Backfill. Place In Lifts / Vibratory Compact. “Target” Clean Gravel Surface. Re-Compact Prior To Placing Fill. Pad Footing Over-Excavation On Individual Basis “Target” Clean Gravel Surface. Re-Compact Prior To Pouring Ftgs Or Placing Struct. Fill. “Target” Clean Gravel Surface. Re-Compact Prior To Pouring Ftgs Or Placing Struct. Fill. All Footings Must Bear On “Target” Sandy Gravel Or On Granular Structural Fill That In Turn Bears On “Target” Gravel. All Excavations And Structural Fill Under Footings Must Be Centered Under The Footing. Note: If Native Gravel Is Wet, Place An Initial Thin Layer Of Clean Crushed Rock Covered By Non-Woven Fabric Prior To Structural Fill. Vibratory Compact The Rock. Excavations Should Be Wide Enough To Permit The Use Of A Large, Smooth Drum Roller For Compaction Of Gravel Subgrade And Granular Structural Fill. Footing Subgrade Will Consist Of Native Silt/Clay. Dig With Smooth- Edged Bucket To Prevent Disturbance. Vibratory Compact To Re-Tighten Soils And Induce Consolidation/Settlement. Due To Dry Soils, Construction Water May Need To Be Added To Facilitate Better Compaction. (Typ. All Locations) Over-Excavation And Structural Fill To Be Centered Under Footing And Extend A Minimum Of 2.0’ Beyond Outside Edge Of Ftg In All Directions. Over-Excavation And Structural Fill To Be Centered Under Footing And Extend A Minimum Of 2.0’ Beyond Outside Edge Of Ftg In All Directions. Strip Topsoil Before Placing Fill Material. Strip Gravel. Depending On The Number/Spacing Of Interior Footings. Consideration Should Be Given To Mass Excavating Down To “Target” Gravel Throughout Foundation Footprint And Increasing Thickness Of The 12-Inch Structural Fill Layer. By Doing This, Over-Excavation (On An Individual Basis) Under Interior Footings Could Be Avoided. H Min. Width = H / 2 Min. Width = H / 2 Existing Ground If Required, Damp Proofing Per Bldg Code Perimeter Footing And Foundation Wall (typ.) Depth To “Target” Sandy Gravel Is 2.0’ To 4.0’ (typ.). (See Fig. 1 & 3 For Gravel Depth In Project Area.) Note: Some Perimeter Footing Locations May Bear In The “Target” Clean Gravel. Strip All Topsoil Prior To Filling. Most Likely, Perimeter Footings Will Readily Bear In Or Near “Target” Gravel (Meaning Either No Req’d Structural Fill Or Only A Relatively Thin Amount). The Benefit Of Mass Over-Excavation And Replacement Is That Interior Footings Now Do Not Have To Be Over- Excavated On An Individual Basis. “Target” Clean Gravel Must Be Exposed Throughout The Bottom Of Excavation. Re-Compact Subgrade Prior To Structural Fill Placement. See Figure 5 For An Illustration That ShowsA Crawl Space Foundation Configuration. We Recommend Mass Over-Excavation Under Slab-On-Grade Foundations Down To “Target” Bearing (In Lieu Of Trench Excavating Under All Perimeter, Interior, And Exterior Footings On An Individual Basis). This Excavation Approach Is Faster; But It Requires In-Filling/Backfilling Inside The Foundation Walls With Granular Structural Fill Back Up To Interior Footing Grade. For Figure 6, We Have Shown A Deep Native Gravel Surface To Purposely Illustrate The Need For The Placement Of A Structural Fill Building Pad Back Up To Perimeter Footing Grade. Due To Shallow Gravels, Most Perimeter Footings Should Readily Bear In/Near The “Target” Gravels. Due To The Complexity Of Most Foundation Plans (Many/Closely Spaced Interior Footings),Individual Footing Over-Excavation Is Time Consuming, Difficult, And Not Recommended. Due To The Shallow Gravels, Assumed Complexity Of The Foundation Plan (Number And Spacing Of Interior Footings), And Need To Fully Remove All Fill Material (That Was Found In The NE Corner), The Best Approach Will Likely Be Mass Over-Excavation Of The Entire Foundation Footprint Area. Some Perimeter Ftgs May Require Some Struct. Fill. No Underslab Drains Req’d. Due To Shallow Gravels And Likely Complexity Of The Foundation Plan (Many/Closely Spaced Interior Footings), We Assume Most Building Foundations Will Be Mass Over-Excavated Down To “Target” Gravel And Re-Filled With Structural Fill Up To Interior Footing Grade. Interior Footings Will Most Likely Require Struct. Fill. Min. Exc. Width = H / 2; 5.0’ (min.) Given The Shallow Gravel Depth In Most Areas, Footing Grade Should Be Close To “Target” Gravel. H As Required To Build Up To Footing Grade From “Target” Gravel Surface. Granular Structural Fill In-Fill To 18” Below Slab. Use Large Smooth Drum Roller For Compaction Of Native Gravel Subgrade And Granular Structural Fill. “Target” Clean Gravel Surface At Bottom Of Mass Excavation. If The Surface Is Dry, Vibratory Re-Compact Prior To Pouring Footings Or Placing Granular Structural Fill. Dig Foundation Exc. With Smooth-Edged Bucket To Prevent Disturbance To Native Gravel Subgrade. “Target” Clean Gravel Surface At Bottom Of Mass Excavation. If The Surface Is Wet, Track-Pack With Excavator And Static Roll With Roller Prior To Placing Crushed Rock. Note: This Figure Illustrates A Deep Gravel Surface And Need For Struct. Fill Under Perimeter Ftgs. And Possible Need For Fabric-Covered, Clean Crushed Rock To Get Above Wet Conditions. If Groundwater Is Above The Native Gravel, Lower Groundwater By De-Watering. If The Gravel Subgrade Is Wet Or Contains Areas Of Shallow Standing Water, Place And Vibratory Compact An Initial Layer Of 1”-Minus Clean Crushed Rock To Get Above The Wet Conditions. Cover The Crushed Rock Layer With A Layer Of 8 oz. Non-Woven Geotextile Fabric Prior To Placing The Granular Structural Fill. 12” (min.) Structural Fill Layer Under Slab Areas (typ.) LIMITATIONS OF YOUR GEOTECHNICAL REPORT GEOTECHNICAL REPORTS ARE PROJECT AND CLIENT SPECIFIC Geotechnical investigations, analyses, and recommendations are project and client specific. Each project and each client have individual criterion for risk, purpose, and cost of evaluation that are considered in the development of scope of geotechnical investigations, analyses and recommendations. For example, slight changes to building types or use may alter the applicability of a particular foundation type, as can a particular client’s aversion or acceptance of risk. Also, additional risk is often created by scope-of- service limitations imposed by the client and a report prepared for a particular client (say a construction contractor) may not be applicable or adequate for another client (say an architect, owner, or developer for example), and vice-versa. No one should apply a geotechnical report for any purpose other than that originally contemplated without first conferring with the consulting geotechnical engineer. Geotechnical reports should be made available to contractors and professionals for information on factual data only and not as a warranty of subsurface conditions, such as those interpreted in the exploration logs and discussed in the report. GEOTECHNICAL CONDITIONS CAN CHANGE Geotechnical conditions may be affected as a result of natural processes or human activity. Geotechnical reports are based on conditions that existed at the time of subsurface exploration. Construction operations such as cuts, fills, or drains in the vicinity of the site and natural events such as floods, earthquakes, or groundwater fluctuations may affect subsurface conditions and, thus, the continuing adequacy of a geotechnical report. GEOTECHNICAL ENGINEERING IS NOT AN EXACT SCIENCE The site exploration and sampling process interprets subsurface conditions using drill action, soil sampling, resistance to excavation, and other subjective observations at discrete points on the surface and in the subsurface. The data is then interpreted by the engineer, who applies professional judgment to render an opinion about over-all subsurface conditions. Actual conditions in areas not sampled or observed may differ from those predicted in your report. Retaining your consultant to advise you during the design process, review plans and specifications, and then to observe subsurface construction operations can minimize the risks associated with the uncertainties associated with such interpretations. The conclusions described in your geotechnical report are preliminary because they must be based on the assumption that conditions revealed through selective exploration and sampling are indicative of actual Allied Engineering Services, Inc. Page 2 conditions throughout a site. A more complete view of subsurface conditions is often revealed during earthwork; therefore, you should retain your consultant to observe earthwork to confirm conditions and/or to provide revised recommendations if necessary. Allied Engineering cannot assume responsibility or liability for the adequacy of the report’s recommendations if another party is retained to observe construction. EXPLORATIONS LOGS SHOULD NOT BE SEPARATED FROM THE REPORT Final explorations logs developed by the consultant are based upon interpretation of field logs (assembled by site personnel), field test results, and laboratory and/or office evaluation of field samples and data. Only final exploration logs and data are customarily included in geotechnical reports. These final logs should not be redrawn for inclusion in Architectural or other design drawings, because drafters may commit errors or omissions in the transfer process. To reduce the likelihood of exploration log misinterpretation, contractors should be given ready access to the complete geotechnical report and should be advised of its limitations and purpose. While a contractor may gain important knowledge from a report prepared for another party, the contractor should discuss the report with Allied Engineering and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for construction cost estimating purposes. OWNERSHIP OF RISK AND STANDARD OF CARE Because geotechnical engineering is much less exact than other design disciplines, there is more risk associated with geotechnical parameters than with most other design issues. Given the hidden and variable character of natural soils and geologic hazards, this risk is impossible to eliminate with any amount of study and exploration. Appropriate geotechnical exploration, analysis, and recommendations can identify and lesson these risks. However, assuming an appropriate geotechnical evaluation, the remaining risk of unknown soil conditions and other geo-hazards typically belongs to the owner of a project unless specifically transferred to another party such as a contractor, insurance company, or engineer. The geotechnical engineer’s duty is to provide professional services in accordance with their stated scope and consistent with the standard of practice at the present time and in the subject geographic area. It is not to provide insurance against geo-hazards or unanticipated soil conditions. The conclusions and recommendations expressed in this report are opinions based our professional judgment and the project parameters as relayed by the client. The conclusions and recommendations assume that site conditions are not substantially different than those exposed by the explorations. If during construction, subsurface conditions different from those encountered in the explorations are observed or appear to be present, Allied Engineering should be advised at once such that we may review those conditions and reconsider our recommendations where necessary. RETENTION OF SOIL SAMPLES Allied Engineering will typically retain soil samples for one month after issuing the geotechnical report. If you would like to hold the samples for a longer period of time, you should make specific arrangements to have the samples held longer or arrange to take charge of the samples yourself. STORMWATER DESIGN REPORT FOR: GRAN CIELO PHASE 2 SUBDIVISION BOZEMAN, MT Prepared By: Madison Engineering 895 Technology Blvd Ste 203 Bozeman, MT 59718 (406) 586-0262 January 2021 Gran Cielo Phase 2 Subdivision Stormwater Design Report Page 1 of 3 GRAN CIELO PHASE 2 SUBDIVISION STORMWATER DESIGN REPORT A. Introduction This design report will give an overview of the stormwater management plan for the proposed Gran Cielo Phase 2 Subdivision in Bozeman, MT. Phase 1 infrastructure was completed in 2020, and Phase 2 expands on the existing infrastructure. The Phase 2 site is currently undeveloped and is vacant. Stormwater management within the subdivision will be accomplished with the combination of surface/gutter flow, pipe conveyance, and detention facilities. Monolithic curb and gutters and valley gutters will be utilized to transfer stormwater to the drain inlets which will be connected to the closed conveyance piping collection system. The stormwater detention ponds and flow control structures will control and meter the discharge of the increased flow to the 10-year pre-development flows and will help remove solids, silt, oils grease and other pollutants from the stormwater, with the first 0.5 inches of rainfall from a 24-hour storm event preceded by 48 hours of no measurable precipitation also captured. The collection system will be designed to convey the 25-year storm event. The following references were used in the preparation of this report: a. COB Design Standards and Specifications Policy, 2004. Addendum #7 b. COB Modifications to Montana Public Works Standard Specifications (MPWSS). Addendum #3 c. Bozeman Stormwater Master Plan - 1982 B. Site Information and Groundwater Monitoring The Phase 2 site lies within Southeast Bozeman and is an undeveloped pasture. Phase 1 improvements were completed in 2020. Groundwater monitoring was conducted between 2017 and 2018 at eight monitoring wells across the subdivision. Groundwater was observed in all of the wells, with depths ranging from 1.0 ft to 7.0 ft below the existing ground surface. C. Peak Flow (Runoff) Calculations The project area was divided into drainage areas as shown on Sheets SD1.0 (Phase 1) and SD1.1 (Phase 2), provided in the Appendix. These areas were used to determine the stormwater runoff flows, which in turn were used to determine the size of the storm drain pipes, gutter capacities, curb inlet sizes, and pond volumes. The Rational method was utilized to determine the 25-year peak flows in accordance with the City of Bozeman Design Standards. The Phase 2 flows were determined utilizing the runoff coefficients provided in Table I-1 of the Design Standards and a higher runoff coefficient for roadways. The peak flows and calculations for the Phase 1 and Phase 2 areas are included in the Appendix. D. Conveyance Structures Runoff from the basins generally flows overland into the proposed curb and gutter. The curb and gutter directs flows into curb inlets and stormwater piping. The piping conveys the flows into the detention ponds. All conveyance structures were sized to carry the 25-year storm event peak runoff flows. Gran Cielo Phase 2 Subdivision Stormwater Design Report Page 2 of 3 The proposed curb and gutter at a minimum slope of 0.5% has a capacity of about 3 cfs while flowing at a depth of 0.15 ft from the top of the curb per City Standards. Where runoffs flowing into curb exceed this amount, steeper slopes and curb inlets are provided. Calculations for the curb capacity are included in the Appendix. Curb inlets were strategically placed throughout the proposed streets to intercept runoffs. The curb inlets were sized to capture all of the runoff from the proposed development. The proposed curb inlets and stormwater piping are displayed on Sheet SD1.2 included in the Appendix. Curb inlet capacity calculations and a curb inlet summary are included in the Appendix. Stormwater piping was included in the design between curb inlets as well as into and out of the detention ponds. The stormwater piping is displayed on Sheet SD1.2 in the Appendix. All piping was sized to convey the 25-year peak runoffs utilizing Manning’s equation for circular channels. When sizing the stormwater infrastructure for the subdivision, a Manning’s roughness coefficient (n) of 0.013 for PVC pipe was not used per Table I-2 of the Bozeman DSSP. Based on the Handbook of PVC pipe, and the Civil Engineering Reference Manual, the recommended n value is 0.009 for design of PVC sewers (see Appendix). Piping capacity calculations and a summary are included in the Appendix. E. Stormwater Detention Ponds The stormwater design includes two new detention ponds for Phase 2. Phase 1 included construction of one detention pond on Bennett Ave, and numerous temporary retention ponds. The temporary retention ponds will be removed with Phase 2, and the new Phase 2 ponds will accommodate the runoff from some of the Phase 1 drainage areas. The detention ponds are designed to handle the 10-year, 2-hr storm event. All ponds have a 4:1 side slope and are 1.5 ft deep maximum with 6 in depth of freeboard. See Table 1 below for a summary of the detention pond volumes. Pond calculations are provided in the Appendix. DETENTION POND SUMMARY Pond ID Contributing Basins* 10-yr, 2-hr Post Development Peak Runoff (cfs) Required Volume (C.F.) Approx. Proposed Volume (C.F.) Existing 3, 4, 5, 14, 15 5.87 8,753 13,385 Apex 2, 12, 16, 17, 18 6.56 9,664 9,687 Bennet 6, 7, 8, 9, 13 7.72 12,105 12,220 * See Sheet SD1.0 & SD1.1 Storm Drainage Basins The Phase 1 report utilized the existing Meadow Creek Subdivision pond for detainment of Basin 11. Also, per the Phase 1 report, Basin 10 is detained by a temporary retention pond and will be addressed with a future extension of Graf Street to the west, outside of the scope of this project. The proposed project does not fully construct S 27th Ave to a collector standard with this development. S 27th Ave will be fully built out with the future property development on the East side of S 27th Ave adjacent to the Gran Cielo Subdivision, outside the scope of this project. Excerpts from the Phase 1 Stormwater Report are included in the Appendix. Gran Cielo Phase 2 Subdivision Stormwater Design Report Page 3 of 3 Basin 1 is the eastern half of S 27th Ave Arterial standard installed with this project, between Graf Street and Cielo Way. However, between Cielo Way and the existing dead end of S 17th Ave at Bennett Blvd, this project only installs the western half of S 27th Ave to a Local street standard. Future development adjacent to S 27th Ave on the East side will be required to widen S 27th Ave to a full Arterial standard. Therefore, Basin 1, which is the eastern half of S 27th installed with this project, is unique in that it will temporarily utilize the Apex pond for treatment and storage. When the widening of the remainder of S 27th Ave to a full Arterial occurs, the widening will require detention or retention storage to account for Basin 1 and the remaining eastern half of the S 27th Ave Arterial. F. Half-inch requirement The half-inch requirement per Bozeman DSSP II.A.4 was accounted for the impervious areas within the subdivision by elevating the weirs of the Detention Facilities. The elevate weir allows for storage and treatment of the first half-inch. The impervious areas within the subdivision that were included in the calculations include the roads and approximately 25% of the net developable lot areas. G. Off-Site Impacts It is not anticipated that property development downstream of the project will be adversely impacted. The proposed detention ponds reduce the runoffs to the pre-development flow rate. The ultimate destination of the runoff from this project is the southern ditch on Stucky Road. The runoffs are conveyed from the ponds via grass swales and irrigation ditches to the Stucky Road ditch. Appendices A. Stormwater Exhibits B. Runoff and Conveyance Calculations C. Detention Pond Calculations D. Groundwater Monitoring Information E. Manning’s n Documentation F. Excerpts from Phase 1 Stormwater Report G. Stormwater Maintenance Plan Appendix A: Stormwater Exhibits S. 27TH AVE S. 30TH AVE S. 31ST AVE S. 29TH AVE S. 28TH AVE CIELO WAYTIERRA LANES. 29TH AVE GRAF STREETBENNETT BLVDAPEX DRIVEBASIN 1 BASIN 3 BASIN 4 BASIN 6 BASIN 18 BASIN 15BASIN 11BASIN 10BASIN 2 BASIN 5 BASIN 7 BASIN 8 BASIN 9 BASIN 12BASIN 13 BASIN 14 BASIN 16 BASIN 17 CIELO WAYSHEETMADISON ENGINEERING895 TECHNOLOGY BLVD, SUITE 203BOZEMAN, MT 59718(406) 586-0262 (406) 586-5740 FAXOF GRAN CIELO EXHIBITGRAN CIELO SUBDIVISIONSTORM DRAINAGE BASINSBOZEMAN, MT1 inch = 0 SCALE 200' 400'100'200'SD1.0 S. 27TH AVE S. 29TH AVE BENNETT BLVDAPEX DRIVES. 30TH AVE S. 31ST AVE S. 28TH AVE CIELO WAYTIERRA LANES. 29TH AVE GRAF STREETCIELO WAYPHASE 1 DRAINAGE AREAS SEE SHEET SD1.0 S. 29TH AVE SHEETMADISON ENGINEERING895 TECHNOLOGY BLVD, SUITE 203BOZEMAN, MT 59718(406) 586-0262 (406) 586-5740 FAXOF GRAN CIELO EXHIBITGRAN CIELO PHASE 2 SUBDIVISIONSTORM DRAINAGE BASINSBOZEMAN, MT1 inch = 0 SCALE 200 feet 400'100'200'SD1.1 APEX DRIVES. 29TH AVE S. 29TH AVE BENNETT BLVDS. 30TH AVE S. 31ST AVE SHEETMADISON ENGINEERING895 TECHNOLOGY BLVD, SUITE 203BOZEMAN, MT 59718(406) 586-0262 (406) 586-5740 FAXOF GRAN CIELO EXHIBITGRAN CIELO PHASE 2 SUBDIVISIONSTORM DRAINAGE PIPING & INLETSBOZEMAN, MT1 inch = 0 SCALE 100' 200'50'100'SD1.2 S. 28TH AVE Appendix B: Runoff and Conveyance Calculations Basin Area (sf)C D (ft)S (%)TC (min)I (in/hr)Q25 (cfs) 18A 157075 0.50 633 1.00 25.88 1.34 2.41 18B 8381 0.73 277 0.50 11.65 2.23 0.31 18C 74509 0.50 395 1.00 20.44 1.55 1.33 18D 81187 0.50 397 1.00 20.49 1.55 1.45 18E 6700 0.73 220 2.00 6.54 3.22 0.36 18F 19156 0.73 640 2.00 11.15 2.29 0.74 18G 20161 0.73 666 0.50 18.06 1.68 0.57 13A 87616 0.50 433 1.00 21.40 1.51 1.52 13B 47628 0.50 387 1.00 20.23 1.56 0.8613C 36749 0.50 300 1.00 17.81 1.70 0.7213D 35378 0.50 300 1.00 17.81 1.70 0.69 13E 215352 0.50 788 0.75 31.78 1.17 2.90 13F 20092 0.73 666 0.50 18.06 1.68 0.57 Gran Cielo Phase 2 Post- Constructed 25-Year Peak Flow Summary Allowable Pavement Encroachment Given: T =9 feet (max per city)W =1.5 feet Ts =7.5 feet Sw =0.08 ft/ft Sx =0.03 ft/ft a =0.96 inches d =3.24 n =0.015 Sw/Sx =2.67 T/W =6 Capacity for Gutter equations: Where: Qs = Discharge within the Roadway above the depressed section (cfs) Qw = Discharge within the depressed (gutter) section (cfs) Cf = 0.56 for English units Sx = Pavement cross slope (ft/ft) Ts = Width of flow in the roadway above depressed section So = Gutter longitudinal slope (ft/ft)Sw = Gutter depression cross slope (ft/ft) T = Spread (ft/ft) W = Width of gutter depression (ft/ft) Capacity solutionMinimum 0.5% Gutter Capacity (Bennett & Apex)1% Gutter Capacity (All Other Streets) So =0.005 So =0.01 Qs =1.65 cfs Qs =2.33 cfs Eo =0.44 cfs Eo =0.44 cfs Q =2.96 cfs Q =4.19 cfs Basin 13A 13B 13C 13D 13E 13F 18A18B18C 1.52 Gran Cielo Subdivision - Phase 2Gutter Capacity Calculations 25 Yr Design Flow 2.410.31 0.86 0.72 0.69 2.90 0.57 1.33 SWQQQ QEQoW 0 S E1 QQ 2 1 O3 8 S3 5 XfS STSn CQ   1 8/3 XW XWo 11T/W /SS1 /SS1E             Page 1 of 2 18D18E18F 18G Summary 1.45 At the minimum project slope of 0.5%, the proposed curb and gutter has the capacity to convey the necessary flows with a freeboard of 0.15' below the top of curb per city standards. Streets with additional runoff from the Phase 1 areas are steeper than 1% and include curb inlets. 0.57 0.740.36 Page 2 of 2 Gran Cielo Phase 2 Subdivision Stormwater Inlet Capacity Summary Inlet Contributing Basin Inflow Q(25) (cfs) Inlet Type Inlet Capacity (cfs) Combo Inlet 1 18A 2.41 Single 2.51 Combo Inlet 2 18B 0.31 Sag 4.86 Combo Inlet 3 18G 0.57 Sag 4.86 Combo Inlet 4 18E 0.36 Single 2.51 Combo Inlet 5 18D 1.45 Single 2.51 Combo Inlet 6 None - this inlet is needed for connecting to an existing storm pipe NA Single NA Combo Inlet 7 13D 0.69 Single 2.51 Combo Inlet 8 13C 0.72 Single 2.51 Combo Inlet 9 13A, 8 4.26 Single 2.51 Curb Inlet 1 18F 0.74 Single 2.51 Curb Inlet 2 13F 0.57 Sag 4.86 Curb Inlet 3 13E 2.90 Sag 4.86 Curb Inlet 4 13B, 9 2.08 Single 2.51 Curb Inlet 5 7 1.08 Single 2.51 Curb Inlet 6 6 1.08 Single 2.51 Curb Inlet 7 5 2.09 Single 2.51 Double Curb Inlet 8 4 3.26 Double 5.02 Notes: Single inlets consist of a City Standard 24" x 36" inlet frame located on flowpaths without a sag in the curb Sag inlets consist of a City Standard 24" x 36" inlet frame located at a sag point in the flowpath See separate Inlet Capacity Calculations for additional information DA Q(25) (cfs) 4 3.26 5 2.09 6 1.84 7 1.08 8 2.74 9 1.22 18A 2.41 18B 0.31 18C 1.33 * this basin flows directly into the Pond 18D 1.45 18E 0.36 18F 0.74 18G 0.57 13A 1.52 13B 0.86 13C 0.72 13D 0.69 13E 2.90 13F 0.57 Gutter Section Appendix F Given: T =9.0 feet W =1.50 feet Ts =7.50 feet Sw =0.08 ft/ft Sx =0.03 ft/ft a =0.96 inches d =3.24 inches n =0.015 So =0.005 Where: Qs = Discharge within the Roadway above the depressed section (cfs) Qw = Discharge within the depressed (gutter) section (cfs) Capacity for Inlets on Grade Cf = 0.56 for English units (Standard 24x36 Curb inlet) Sx = Pavement cross slope (ft/ft) Ts = Width of flow in the roadway above depressed section So = Gutter longitudinal slope (ft/ft) Qw =2.96 cfs Sw = Gutter depression cross slope (ft/ft) Qs =1.65 cfs T = Spread (ft/ft) Cross-sectional area of flow W = Width of gutter depression (ft/ft) A =1.22 ft2 Gutter Velocity V =3.79 ft/sec Fraction of side flow intercepted Rs =0.18 Total flow capacity intercepted by the inlet Qint =2.51 cfs Qbypass =2.10 cfs Double Inlet Capacity =5.01 cfs *twice a single inlet capacity Gran Cielo Subdivision Inlet Capacity Calculations Page 1 of 1 Basins A, B & C East Jordan Iron Works Orifice Flow Calculations: From Manufacturer's Website Where: Q = Flow (cfs) A = Open area in grate (in^2) d = Depth of water over grate (in) C = Rating Coefficient C = 0.0108 *From Manufacturer A = 225 in^2 *From Shop Drawing Submittal d = 4 in *City Maximum Q =4.86 cfs Gran Cielo Phase 2 Orifice Type (Sag) Curb Inlet Capacity Calculations 𝑄=𝐶∗𝐴∗√𝑑 Gran Cielo Phase 2 Subdivision Stormwater Pipe Capacity Summary Pipe Contributing Basin Inflow Q(25) (cfs)Pipe Size Pipe Material Pipe Slope Pipe Capacity (cfs) A1 1, 2, 12, 16, 17 3.97 15" PVC 0.38% 6.2 A2 18A 2.41 15" PVC 0.50% 7.1 A3 1, 2, 12, 16, 17, 18A 6.38 18" RCP 0.38% 7.0 B1 Ex. Pond 2 2.77 15" PVC 1.05% 10.3 B2 Ex. Pond 2 2.77 15" PVC 1.05% 10.3 B3 18D 1.45 15" PVC 0.50% 7.1 B4 18D, Ex. Pond 2 4.22 15" PVC 2.14% 14.7 B5 18D, 18E, Ex. Pond 2 4.58 15" PVC 1.90% 13.8 C1 6 1.84 15" PVC 0.50% 7.1 C2 6, 7 2.92 15" PVC 0.68% 8.3 C3 13B, 9 2.08 15" PVC 0.50% 7.1 C4 6, 7, 8, 9, 13A, 13B 9.25 18" PVC 1.63% 20.8 C5 6, 7, 8, 9, 13A, 13B, 13C 9.97 18" PVC 0.50% 11.5 C6 6, 7, 8, 9, 13A, 13B, 13C, 13D 10.66 18" PVC 3.23% 29.3 D1 13F 0.57 15" RCP 0.50% 4.9 D2 13F, 13E 3.46 15" PVC 0.50% 7.1 E1 Irrigation 3.00 15" PVC 1.50% 12.3 E2 Bennet Pond Outflow 3.09 15" PVC 2.50% 15.9 E3 Irrigation, Bennet Pond Outflow 6.09 15" PVC 0.50% 7.1 F1 18C, 18D, 18E, Ex. Pond 2 5.91 18" PVC 2.00% 23.1 F2 1, 2, 12, 16, 17, 18A, 18B, 18C, 18D, 18E, Ex. Pond 2 12.60 21" RCP 0.60% 13.2 F3 18F 0.74 15" RCP 0.50% 4.9 F4 1, 2, 12, 16, 17, 18A, 18B, 18C, 18D, 18E, 18F, 18G, Ex. Pond 2 13.90 21" PVC 0.50% 17.4 F5 Apex Pond Outflow 1.48 21" PVC 0.50% 17.4 G1 4 3.26 15" PVC 0.50% 7.1 G2 4, 5 5.35 15" PVC 1.58% 12.6 DA Q(25) (cfs) 1 0.97 2 0.68 4 3.26 5 2.09 6 1.84 7 1.08 8 2.74 9 1.22 12 0.49 16 0.97 17 0.86 18A 2.41 18B 0.31 18C 1.33 18D 1.45 18E 0.36 18F 0.74 18G 0.57 13A 1.52 13B 0.86 13C 0.72 13D 0.69 13E 2.90 13F 0.57 Ex. Pond 2 2.77 * this is the design outflow of existing pond 2 Irrigation 3 * this is the estimated irrigation flow rate Bennet 3.09 * this is the Bennet Pond Design Outflow Apex 1.48 * This is the Apex Pond design outflow PIPE A1Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter ValueDiameter,do (ft) =1.25 Units =1.486n =0.009 pvcSlope, S (ft/ft)0.0038 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.0 12.4 5950.3 1.2 0.020.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.1 53.9 25869.6 1.9 0.050.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.3 125.5 60231.7 2.4 0.090.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 0.5 226.1 108509.4 2.9 0.130.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 0.8 353.6 169733.8 3.3 0.170.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 1.1 505.5 242653.9 3.6 0.210.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 1.5 678.8 325808.1 4.0 0.240.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 1.9 869.9 417560.7 4.2 0.280.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 2.4 1075.3 516120.7 4.5 0.310.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 2.9 1290.7 619548.7 4.7 0.340.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 3.4 1512.0 725752.9 4.9 0.370.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 3.9 1734.3 832475.4 5.0 0.390.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 4.4 1952.6 937263.7 5.2 0.410.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 4.8 2161.3 1037419.0 5.2 0.430.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 5.2 2354.0 1129905.3 5.3 0.441.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 5.6 2523.3 1211176.7 5.3 0.441.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 5.9 2660.0 1276816.0 5.3 0.441.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 6.1 2751.3 1320626.7 5.3 0.431.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 6.2 2773.8 1331428.2 5.1 0.411.25 6.28 1.23 3.93 0.31 0.00 5.8 2582.3 1239516.3 4.7 0.34 Q = 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE A2, B3, C1, C3, D2, E3, G1 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter Value Diameter,do (ft) =1.25 Units =1.486 n =0.009 PVC Slope, S (ft/ft)0.005 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00 0.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.0 14.2 6825.4 1.4 0.03 0.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.1 61.8 29674.5 2.2 0.07 0.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.3 143.9 69090.5 2.8 0.12 0.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 0.6 259.3 124468.8 3.3 0.17 0.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 0.9 405.6 194698.0 3.8 0.22 0.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 1.3 579.9 278343.1 4.2 0.27 0.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 1.7 778.6 373727.5 4.5 0.32 0.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 2.2 997.9 478974.9 4.9 0.37 0.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 2.7 1233.4 592031.1 5.1 0.41 0.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 3.3 1480.6 710671.1 5.4 0.45 0.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 3.9 1734.4 832495.6 5.6 0.48 0.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 4.4 1989.4 954914.8 5.8 0.52 0.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 5.0 2239.8 1075115.2 5.9 0.54 0.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 5.5 2479.2 1190001.2 6.0 0.56 0.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 6.0 2700.2 1296090.2 6.1 0.58 1.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 6.4 2894.4 1389314.9 6.1 0.58 1.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 6.8 3051.3 1464608.4 6.1 0.58 1.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 7.0 3156.0 1514862.7 6.0 0.57 1.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 7.1 3181.8 1527252.8 5.9 0.541.25 6.28 1.23 3.93 0.31 0.00 6.6 2962.1 1421822.7 5.4 0.45 Q = 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE A3Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =18 Enter ValueDiameter,do (ft) =1.5 Units =1.486n =0.013 RCPSlope, S (ft/ft)0.0038 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.08 0.90 0.03 0.68 0.05 0.65 0.05 0.01 0.0 14.0 6698.6 0.9 0.010.15 1.29 0.09 0.97 0.10 0.90 0.10 0.03 0.1 60.7 29123.2 1.5 0.030.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 0.3 141.3 67807.0 1.9 0.060.30 1.85 0.25 1.39 0.18 1.20 0.21 0.12 0.6 254.5 122156.5 2.3 0.080.38 2.09 0.35 1.57 0.22 1.30 0.27 0.18 0.9 398.1 191081.0 2.6 0.100.45 2.32 0.45 1.74 0.26 1.37 0.32 0.25 1.3 569.1 273172.2 2.8 0.130.53 2.53 0.55 1.90 0.29 1.43 0.39 0.34 1.7 764.1 366784.5 3.1 0.150.60 2.74 0.66 2.05 0.32 1.47 0.45 0.44 2.2 979.3 470076.7 3.3 0.170.68 2.94 0.77 2.21 0.35 1.49 0.52 0.55 2.7 1210.5 581032.5 3.5 0.190.75 3.14 0.88 2.36 0.38 1.50 0.59 0.68 3.2 1453.1 697468.5 3.7 0.210.83 3.34 1.00 2.51 0.40 1.49 0.67 0.81 3.8 1702.1 817029.8 3.8 0.230.90 3.54 1.11 2.66 0.42 1.47 0.75 0.96 4.4 1952.4 937174.7 3.9 0.240.98 3.75 1.22 2.81 0.43 1.43 0.85 1.12 4.9 2198.2 1055142.1 4.0 0.251.05 3.96 1.32 2.97 0.44 1.37 0.96 1.30 5.4 2433.1 1167893.8 4.1 0.261.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 5.9 2650.0 1272011.9 4.2 0.271.20 4.43 1.52 3.32 0.46 1.20 1.26 1.70 6.3 2840.6 1363504.7 4.2 0.271.28 4.69 1.60 3.52 0.45 1.07 1.49 1.96 6.7 2994.6 1437399.4 4.2 0.271.35 5.00 1.68 3.75 0.45 0.90 1.86 2.29 6.9 3097.3 1486720.1 4.1 0.261.43 5.38 1.73 4.04 0.43 0.65 2.65 2.82 7.0 3122.7 1498880.1 4.0 0.251.50 6.28 1.77 4.71 0.38 0.00 6.5 2907.1 1395408.6 3.7 0.21 Q = 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE B1, B2Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter ValueDiameter,do (ft) =1.25 Units =1.486n =0.009 PVCSlope, S (ft/ft)0.0105 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.0 20.6 9891.0 2.0 0.060.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.2 89.6 43002.5 3.1 0.150.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.5 208.6 100121.7 4.0 0.250.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 0.8 375.8 180372.4 4.8 0.360.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 1.3 587.8 282144.2 5.5 0.460.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 1.9 840.3 403357.5 6.0 0.570.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 2.5 1128.3 541582.6 6.6 0.670.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 3.2 1446.0 694100.6 7.0 0.770.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 4.0 1787.4 857934.6 7.4 0.860.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 4.8 2145.5 1029860.2 7.8 0.940.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 5.6 2513.3 1206400.8 8.1 1.020.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 6.4 2882.9 1383803.0 8.4 1.080.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 7.2 3245.8 1557989.9 8.6 1.140.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 8.0 3592.7 1724475.6 8.7 1.180.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 8.7 3912.9 1878213.2 8.8 1.211.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 9.3 4194.4 2013308.6 8.9 1.221.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 9.9 4421.7 2122419.3 8.9 1.221.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 10.2 4573.4 2195244.6 8.8 1.191.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 10.3 4610.8 2213199.6 8.5 1.131.25 6.28 1.23 3.93 0.31 0.00 9.6 4292.5 2060416.9 7.8 0.94 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE B4Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter ValueDiameter,do (ft) =1.25 Units =1.486n =0.009 PVCSlope, S (ft/ft)0.0214 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.1 29.4 14120.6 2.9 0.130.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.3 127.9 61391.1 4.5 0.310.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.7 297.8 142935.6 5.7 0.510.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 1.2 536.5 257503.1 6.8 0.730.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 1.9 839.2 402794.4 7.8 0.940.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 2.7 1199.7 575840.7 8.6 1.160.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 3.6 1610.8 773173.4 9.4 1.370.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 4.6 2064.4 990911.0 10.0 1.560.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 5.7 2551.7 1224803.4 10.6 1.750.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 6.8 3063.0 1470247.8 11.1 1.920.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 8.0 3588.1 1722280.4 11.6 2.080.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 9.2 4115.7 1975543.1 11.9 2.210.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 10.3 4633.8 2224215.6 12.2 2.320.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 11.4 5128.9 2461893.6 12.5 2.410.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 12.4 5586.2 2681372.3 12.6 2.471.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 13.3 5988.0 2874237.0 12.7 2.501.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 14.1 6312.5 3030005.5 12.7 2.491.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 14.5 6529.1 3133972.4 12.5 2.431.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 14.7 6582.5 3159605.3 12.2 2.301.25 6.28 1.23 3.93 0.31 0.00 13.7 6128.1 2941489.8 11.1 1.92 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE B5Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter ValueDiameter,do (ft) =1.25 Units =1.486n =0.009 PVCSlope, S (ft/ft)0.019 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.1 27.7 13305.2 2.7 0.110.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.3 120.5 57846.3 4.2 0.270.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.6 280.6 134682.2 5.4 0.460.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 1.1 505.5 242634.4 6.4 0.650.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 1.8 790.7 379536.3 7.3 0.840.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 2.5 1130.4 542590.6 8.1 1.030.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 3.4 1517.8 728529.0 8.8 1.210.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 4.3 1945.2 933694.0 9.5 1.390.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 5.4 2404.3 1154081.1 10.0 1.550.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 6.4 2886.2 1385353.0 10.5 1.710.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 7.5 3380.9 1622832.8 10.9 1.840.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 8.6 3878.1 1861471.7 11.2 1.960.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 9.7 4366.2 2095785.3 11.5 2.060.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 10.8 4832.8 2319739.4 11.7 2.140.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 11.7 5263.6 2526545.0 11.9 2.191.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 12.6 5642.2 2708273.3 11.9 2.221.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 13.3 5948.0 2855047.4 11.9 2.211.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 13.7 6152.1 2953011.1 11.8 2.161.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 13.8 6202.4 2977163.9 11.5 2.051.25 6.28 1.23 3.93 0.31 0.00 12.9 5774.3 2771642.8 10.5 1.71 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE C2 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter Value Diameter,do (ft) =1.25 Units =1.486 n =0.009 PVC Slope, S (ft/ft)0.0068 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00 0.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.0 16.6 7959.8 1.6 0.04 0.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.2 72.1 34606.1 2.5 0.10 0.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.4 167.9 80572.7 3.2 0.16 0.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 0.7 302.4 145154.3 3.9 0.23 0.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 1.1 473.0 227055.0 4.4 0.30 0.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 1.5 676.3 324601.1 4.9 0.37 0.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 2.0 908.0 435837.4 5.3 0.43 0.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 2.6 1163.7 558575.9 5.7 0.50 0.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 3.2 1438.4 690421.0 6.0 0.56 0.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 3.8 1726.6 828777.8 6.3 0.61 0.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 4.5 2022.6 970848.4 6.5 0.66 0.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 5.2 2320.0 1113612.5 6.7 0.70 0.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 5.8 2612.1 1253789.0 6.9 0.74 0.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 6.4 2891.2 1387767.9 7.0 0.77 0.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 7.0 3148.9 1511487.9 7.1 0.78 1.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 7.5 3375.4 1620205.7 7.1 0.79 1.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 7.9 3558.4 1708012.3 7.1 0.79 1.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 8.2 3680.5 1766618.3 7.0 0.77 1.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 8.3 3710.6 1781067.6 6.9 0.731.25 6.28 1.23 3.93 0.31 0.00 7.7 3454.4 1658116.0 6.3 0.61 Q = 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE C3Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =18 Enter ValueDiameter,do (ft) =1.5 Units =1.486n =0.009 PVCSlope, S (ft/ft)0.005 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.08 0.90 0.03 0.68 0.05 0.65 0.05 0.01 0.1 23.1 11098.9 1.6 0.040.15 1.29 0.09 0.97 0.10 0.90 0.10 0.03 0.2 100.5 48254.0 2.4 0.090.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 0.5 234.1 112348.8 3.1 0.150.30 1.85 0.25 1.39 0.18 1.20 0.21 0.12 0.9 421.7 202400.0 3.7 0.220.38 2.09 0.35 1.57 0.22 1.30 0.27 0.18 1.5 659.6 316600.4 4.3 0.280.45 2.32 0.45 1.74 0.26 1.37 0.32 0.25 2.1 943.0 452616.6 4.7 0.340.53 2.53 0.55 1.90 0.29 1.43 0.39 0.34 2.8 1266.1 607722.1 5.1 0.410.60 2.74 0.66 2.05 0.32 1.47 0.45 0.44 3.6 1622.6 778866.0 5.5 0.470.68 2.94 0.77 2.21 0.35 1.49 0.52 0.55 4.5 2005.6 962707.8 5.8 0.520.75 3.14 0.88 2.36 0.38 1.50 0.59 0.68 5.4 2407.6 1155629.5 6.1 0.570.83 3.34 1.00 2.51 0.40 1.49 0.67 0.81 6.3 2820.3 1353729.7 6.3 0.620.90 3.54 1.11 2.66 0.42 1.47 0.75 0.96 7.2 3235.0 1552796.8 6.5 0.660.98 3.75 1.22 2.81 0.43 1.43 0.85 1.12 8.1 3642.2 1748255.8 6.7 0.691.05 3.96 1.32 2.97 0.44 1.37 0.96 1.30 9.0 4031.4 1935073.1 6.8 0.721.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 9.8 4390.8 2107585.6 6.9 0.741.20 4.43 1.52 3.32 0.46 1.20 1.26 1.70 10.5 4706.6 2259179.2 6.9 0.741.28 4.69 1.60 3.52 0.45 1.07 1.49 1.96 11.1 4961.7 2381614.8 6.9 0.741.35 5.00 1.68 3.75 0.45 0.90 1.86 2.29 11.4 5131.9 2463333.8 6.8 0.721.43 5.38 1.73 4.04 0.43 0.65 2.65 2.82 11.5 5173.9 2483481.5 6.6 0.691.50 6.28 1.77 4.71 0.38 0.00 10.7 4816.8 2312040.6 6.1 0.57 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE C4 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =18 Enter Value Diameter,do (ft) =1.5 Units =1.486 n =0.009 PVC Slope, S (ft/ft)0.0163 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00 0.08 0.90 0.03 0.68 0.05 0.65 0.05 0.01 0.1 41.7 20039.6 2.8 0.12 0.15 1.29 0.09 0.97 0.10 0.90 0.10 0.03 0.4 181.5 87124.9 4.4 0.30 0.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 0.9 422.6 202851.0 5.7 0.50 0.30 1.85 0.25 1.39 0.18 1.20 0.21 0.12 1.7 761.3 365442.7 6.7 0.71 0.38 2.09 0.35 1.57 0.22 1.30 0.27 0.18 2.7 1190.9 571637.0 7.7 0.92 0.45 2.32 0.45 1.74 0.26 1.37 0.32 0.25 3.8 1702.5 817220.6 8.5 1.12 0.53 2.53 0.55 1.90 0.29 1.43 0.39 0.34 5.1 2286.0 1097270.8 9.2 1.33 0.60 2.74 0.66 2.05 0.32 1.47 0.45 0.44 6.5 2929.7 1406279.2 9.9 1.52 0.68 2.94 0.77 2.21 0.35 1.49 0.52 0.55 8.1 3621.3 1738214.2 10.5 1.70 0.75 3.14 0.88 2.36 0.38 1.50 0.59 0.68 9.7 4347.0 2086543.5 11.0 1.87 0.83 3.34 1.00 2.51 0.40 1.49 0.67 0.81 11.3 5092.1 2444222.6 11.4 2.02 0.90 3.54 1.11 2.66 0.42 1.47 0.75 0.96 13.0 5840.9 2803647.6 11.8 2.15 0.98 3.75 1.22 2.81 0.43 1.43 0.85 1.12 14.7 6576.2 3156558.1 12.1 2.25 1.05 3.96 1.32 2.97 0.44 1.37 0.96 1.30 16.2 7278.9 3493865.5 12.3 2.34 1.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 17.7 7927.8 3805344.9 12.4 2.40 1.20 4.43 1.52 3.32 0.46 1.20 1.26 1.70 18.9 8498.0 4079054.3 12.5 2.42 1.28 4.69 1.60 3.52 0.45 1.07 1.49 1.96 20.0 8958.6 4300117.5 12.5 2.41 1.35 5.00 1.68 3.75 0.45 0.90 1.86 2.29 20.6 9266.0 4447665.0 12.3 2.36 1.43 5.38 1.73 4.04 0.43 0.65 2.65 2.82 20.8 9341.8 4484042.6 12.0 2.241.50 6.28 1.77 4.71 0.38 0.00 19.4 8696.9 4174497.9 11.0 1.87 Q = 0.0 5.0 10.0 15.0 20.0 25.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE C5 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =18 Enter Value Diameter,do (ft) =1.5 Units =1.486 n =0.009 PVC Slope, S (ft/ft)0.005 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00 0.08 0.90 0.03 0.68 0.05 0.65 0.05 0.01 0.1 23.1 11098.9 1.6 0.04 0.15 1.29 0.09 0.97 0.10 0.90 0.10 0.03 0.2 100.5 48254.0 2.4 0.09 0.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 0.5 234.1 112348.8 3.1 0.15 0.30 1.85 0.25 1.39 0.18 1.20 0.21 0.12 0.9 421.7 202400.0 3.7 0.22 0.38 2.09 0.35 1.57 0.22 1.30 0.27 0.18 1.5 659.6 316600.4 4.3 0.28 0.45 2.32 0.45 1.74 0.26 1.37 0.32 0.25 2.1 943.0 452616.6 4.7 0.34 0.53 2.53 0.55 1.90 0.29 1.43 0.39 0.34 2.8 1266.1 607722.1 5.1 0.41 0.60 2.74 0.66 2.05 0.32 1.47 0.45 0.44 3.6 1622.6 778866.0 5.5 0.47 0.68 2.94 0.77 2.21 0.35 1.49 0.52 0.55 4.5 2005.6 962707.8 5.8 0.52 0.75 3.14 0.88 2.36 0.38 1.50 0.59 0.68 5.4 2407.6 1155629.5 6.1 0.57 0.83 3.34 1.00 2.51 0.40 1.49 0.67 0.81 6.3 2820.3 1353729.7 6.3 0.62 0.90 3.54 1.11 2.66 0.42 1.47 0.75 0.96 7.2 3235.0 1552796.8 6.5 0.66 0.98 3.75 1.22 2.81 0.43 1.43 0.85 1.12 8.1 3642.2 1748255.8 6.7 0.69 1.05 3.96 1.32 2.97 0.44 1.37 0.96 1.30 9.0 4031.4 1935073.1 6.8 0.72 1.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 9.8 4390.8 2107585.6 6.9 0.74 1.20 4.43 1.52 3.32 0.46 1.20 1.26 1.70 10.5 4706.6 2259179.2 6.9 0.74 1.28 4.69 1.60 3.52 0.45 1.07 1.49 1.96 11.1 4961.7 2381614.8 6.9 0.74 1.35 5.00 1.68 3.75 0.45 0.90 1.86 2.29 11.4 5131.9 2463333.8 6.8 0.72 1.43 5.38 1.73 4.04 0.43 0.65 2.65 2.82 11.5 5173.9 2483481.5 6.6 0.691.50 6.28 1.77 4.71 0.38 0.00 10.7 4816.8 2312040.6 6.1 0.57 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE C6 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =18 Enter Value Diameter,do (ft) =1.5 Units =1.486 n =0.009 PVC Slope, S (ft/ft)0.0323 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00 0.08 0.90 0.03 0.68 0.05 0.65 0.05 0.01 0.1 58.8 28209.6 4.0 0.24 0.15 1.29 0.09 0.97 0.10 0.90 0.10 0.03 0.6 255.5 122645.0 6.2 0.60 0.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 1.3 594.9 285551.7 8.0 0.99 0.30 1.85 0.25 1.39 0.18 1.20 0.21 0.12 2.4 1071.7 514430.6 9.5 1.40 0.38 2.09 0.35 1.57 0.22 1.30 0.27 0.18 3.7 1676.4 804688.5 10.8 1.82 0.45 2.32 0.45 1.74 0.26 1.37 0.32 0.25 5.3 2396.7 1150394.4 12.0 2.23 0.53 2.53 0.55 1.90 0.29 1.43 0.39 0.34 7.2 3218.0 1544618.7 13.0 2.63 0.60 2.74 0.66 2.05 0.32 1.47 0.45 0.44 9.2 4124.2 1979607.2 13.9 3.01 0.68 2.94 0.77 2.21 0.35 1.49 0.52 0.55 11.4 5097.6 2446869.2 14.7 3.37 0.75 3.14 0.88 2.36 0.38 1.50 0.59 0.68 13.6 6119.2 2937209.3 15.4 3.70 0.83 3.34 1.00 2.51 0.40 1.49 0.67 0.81 16.0 7168.1 3440711.2 16.0 3.99 0.90 3.54 1.11 2.66 0.42 1.47 0.75 0.96 18.3 8222.2 3946670.6 16.5 4.25 0.98 3.75 1.22 2.81 0.43 1.43 0.85 1.12 20.6 9257.2 4443459.7 17.0 4.47 1.05 3.96 1.32 2.97 0.44 1.37 0.96 1.30 22.8 10246.4 4918284.5 17.3 4.64 1.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 24.9 11159.9 5356751.3 17.5 4.75 1.20 4.43 1.52 3.32 0.46 1.20 1.26 1.70 26.7 11962.6 5742049.7 17.6 4.80 1.28 4.69 1.60 3.52 0.45 1.07 1.49 1.96 28.1 12610.9 6053238.4 17.6 4.78 1.35 5.00 1.68 3.75 0.45 0.90 1.86 2.29 29.1 13043.6 6260939.8 17.3 4.67 1.43 5.38 1.73 4.04 0.43 0.65 2.65 2.82 29.3 13150.3 6312148.3 16.9 4.431.50 6.28 1.77 4.71 0.38 0.00 27.3 12242.5 5876404.8 15.4 3.70 Q = 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE D1, F3Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter ValueDiameter,do (ft) =1.25 Units =1.486n =0.013 RCPSlope, S (ft/ft)0.005 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.0 9.8 4725.3 1.0 0.010.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.1 42.8 20543.9 1.5 0.030.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.2 99.6 47831.9 1.9 0.060.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 0.4 179.5 86170.7 2.3 0.080.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 0.6 280.8 134790.9 2.6 0.110.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 0.9 401.5 192699.1 2.9 0.130.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 1.2 539.0 258734.4 3.1 0.150.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 1.5 690.8 331598.0 3.4 0.180.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 1.9 853.9 409867.7 3.6 0.200.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 2.3 1025.0 492003.1 3.7 0.220.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 2.7 1200.7 576343.1 3.9 0.230.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 3.1 1377.3 661094.9 4.0 0.250.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 3.5 1550.6 744310.5 4.1 0.260.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 3.8 1716.3 823847.0 4.2 0.270.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 4.2 1869.4 897293.2 4.2 0.281.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 4.5 2003.8 961833.4 4.2 0.281.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 4.7 2112.4 1013959.7 4.2 0.281.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 4.9 2184.9 1048751.1 4.2 0.271.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 4.9 2202.8 1057328.9 4.1 0.261.25 6.28 1.23 3.93 0.31 0.00 4.6 2050.7 984338.8 3.7 0.22 Q = 0.0 1.0 2.0 3.0 4.0 5.0 6.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE E1 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter ValueDiameter,do (ft) =1.25 Units =1.486n =0.009 PVCSlope, S (ft/ft)0.015 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.1 24.6 11822.0 2.4 0.090.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.2 107.1 51397.8 3.7 0.220.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.6 249.3 119668.3 4.8 0.360.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 1.0 449.1 215586.3 5.7 0.510.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 1.6 702.6 337226.9 6.5 0.660.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 2.2 1004.4 482104.4 7.2 0.810.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 3.0 1348.6 647315.0 7.9 0.960.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 3.9 1728.4 829608.9 8.4 1.100.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 4.8 2136.3 1025427.9 8.9 1.230.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 5.7 2564.4 1230918.4 9.3 1.350.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 6.7 3004.0 1441924.8 9.7 1.450.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 7.7 3445.8 1653961.0 10.0 1.550.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 8.6 3879.5 1862154.1 10.2 1.630.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 9.6 4294.0 2061142.5 10.4 1.690.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 10.4 4676.9 2244894.1 10.6 1.731.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 11.2 5013.3 2406364.0 10.6 1.751.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 11.8 5285.0 2536776.2 10.6 1.741.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 12.2 5466.3 2623819.2 10.5 1.701.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 12.3 5511.0 2645279.5 10.2 1.611.25 6.28 1.23 3.93 0.31 0.00 11.4 5130.6 2462669.2 9.3 1.35 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE E2 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter ValueDiameter,do (ft) =1.25 Units =1.486n =0.009 PVCSlope, S (ft/ft)0.025 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.1 31.8 15262.1 3.1 0.150.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.3 138.2 66354.2 4.8 0.360.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.7 321.9 154491.1 6.2 0.600.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 1.3 579.8 278320.7 7.4 0.850.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 2.0 907.0 435358.0 8.4 1.100.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 2.9 1296.7 622394.2 9.3 1.350.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 3.9 1741.0 835680.1 10.1 1.590.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 5.0 2231.3 1071020.5 10.8 1.830.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 6.1 2758.0 1323821.8 11.5 2.040.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 7.4 3310.6 1589108.9 12.0 2.240.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 8.6 3878.2 1861516.8 12.5 2.420.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 9.9 4448.4 2135254.4 12.9 2.580.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 11.2 5008.4 2404030.7 13.2 2.710.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 12.4 5543.6 2660923.6 13.5 2.810.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 13.5 6037.8 2898145.8 13.6 2.881.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 14.4 6472.1 3106602.6 13.7 2.921.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 15.2 6822.8 3274964.0 13.7 2.901.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 15.7 7057.0 3387336.0 13.5 2.841.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 15.9 7114.7 3415041.2 13.2 2.691.25 6.28 1.23 3.93 0.31 0.00 14.8 6623.5 3179292.3 12.0 2.25 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE F1Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =18 Enter ValueDiameter,do (ft) =1.5 Units =1.486n =0.009 PVCSlope, S (ft/ft)0.02 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.08 0.90 0.03 0.68 0.05 0.65 0.05 0.01 0.1 46.2 22197.8 3.1 0.150.15 1.29 0.09 0.97 0.10 0.90 0.10 0.03 0.4 201.1 96508.1 4.9 0.370.23 1.59 0.17 1.19 0.14 1.07 0.16 0.07 1.0 468.1 224697.6 6.3 0.610.30 1.85 0.25 1.39 0.18 1.20 0.21 0.12 1.9 843.3 404800.0 7.5 0.870.38 2.09 0.35 1.57 0.22 1.30 0.27 0.18 2.9 1319.2 633200.9 8.5 1.120.45 2.32 0.45 1.74 0.26 1.37 0.32 0.25 4.2 1885.9 905233.2 9.4 1.380.53 2.53 0.55 1.90 0.29 1.43 0.39 0.34 5.6 2532.2 1215444.2 10.2 1.630.60 2.74 0.66 2.05 0.32 1.47 0.45 0.44 7.2 3245.3 1557732.1 11.0 1.860.68 2.94 0.77 2.21 0.35 1.49 0.52 0.55 8.9 4011.3 1925415.7 11.6 2.090.75 3.14 0.88 2.36 0.38 1.50 0.59 0.68 10.7 4815.1 2311259.1 12.1 2.290.83 3.34 1.00 2.51 0.40 1.49 0.67 0.81 12.6 5640.5 2707459.4 12.6 2.470.90 3.54 1.11 2.66 0.42 1.47 0.75 0.96 14.4 6470.0 3105593.5 13.0 2.630.98 3.75 1.22 2.81 0.43 1.43 0.85 1.12 16.2 7284.4 3496511.7 13.3 2.771.05 3.96 1.32 2.97 0.44 1.37 0.96 1.30 18.0 8062.8 3870146.3 13.6 2.871.13 4.19 1.42 3.14 0.45 1.30 1.09 1.49 19.6 8781.6 4215171.2 13.8 2.941.20 4.43 1.52 3.32 0.46 1.20 1.26 1.70 21.0 9413.2 4518358.4 13.8 2.971.28 4.69 1.60 3.52 0.45 1.07 1.49 1.96 22.1 9923.4 4763229.6 13.8 2.961.35 5.00 1.68 3.75 0.45 0.90 1.86 2.29 22.9 10263.9 4926667.6 13.7 2.891.43 5.38 1.73 4.04 0.43 0.65 2.65 2.82 23.1 10347.8 4966963.0 13.3 2.751.50 6.28 1.77 4.71 0.38 0.00 21.5 9633.5 4624081.1 12.1 2.29 Q = 0.0 5.0 10.0 15.0 20.0 25.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE F2 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =21 Enter ValueDiameter,do (ft) =1.75 Units =1.486n =0.013 RCPSlope, S (ft/ft)0.006 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.09 0.90 0.04 0.79 0.06 0.76 0.06 0.01 0.1 26.5 12696.8 1.3 0.030.18 1.29 0.13 1.13 0.11 1.05 0.12 0.04 0.3 115.0 55201.2 2.0 0.070.26 1.59 0.23 1.39 0.16 1.25 0.18 0.10 0.6 267.8 128523.6 2.6 0.110.35 1.85 0.34 1.62 0.21 1.40 0.24 0.17 1.1 482.4 231539.5 3.1 0.150.44 2.09 0.47 1.83 0.26 1.52 0.31 0.26 1.7 754.5 362181.3 3.6 0.200.53 2.32 0.61 2.03 0.30 1.60 0.38 0.37 2.4 1078.7 517779.7 4.0 0.240.61 2.53 0.75 2.22 0.34 1.67 0.45 0.50 3.2 1448.4 695215.7 4.3 0.290.70 2.74 0.90 2.40 0.37 1.71 0.52 0.65 4.1 1856.2 890999.2 4.6 0.330.79 2.94 1.05 2.57 0.41 1.74 0.60 0.82 5.1 2294.4 1101308.7 4.9 0.370.88 3.14 1.20 2.75 0.44 1.75 0.69 1.00 6.1 2754.2 1322005.3 5.1 0.400.96 3.34 1.36 2.92 0.46 1.74 0.78 1.20 7.2 3226.3 1548625.9 5.3 0.441.05 3.54 1.51 3.10 0.49 1.71 0.88 1.41 8.2 3700.7 1776352.6 5.5 0.461.14 3.75 1.66 3.28 0.50 1.67 0.99 1.65 9.3 4166.6 1999951.9 5.6 0.491.23 3.96 1.80 3.47 0.52 1.60 1.12 1.90 10.3 4611.8 2213665.2 5.7 0.511.31 4.19 1.94 3.67 0.53 1.52 1.28 2.19 11.2 5022.9 2411014.2 5.8 0.521.40 4.43 2.06 3.88 0.53 1.40 1.47 2.50 12.0 5384.2 2584432.8 5.8 0.531.49 4.69 2.18 4.11 0.53 1.25 1.74 2.88 12.6 5676.0 2724495.4 5.8 0.521.58 5.00 2.28 4.37 0.52 1.05 2.17 3.36 13.1 5870.8 2817979.4 5.7 0.511.66 5.38 2.36 4.71 0.50 0.76 3.09 4.15 13.2 5918.8 2841027.8 5.6 0.481.75 6.28 2.41 5.50 0.44 0.00 12.3 5510.2 2644904.5 5.1 0.40 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.00 0.50 1.00 1.50 2.00 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE F4, F5 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =21 Enter ValueDiameter,do (ft) =1.75 Units =1.486n =0.009 RCPSlope, S (ft/ft)0.005 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.000.09 0.90 0.04 0.79 0.06 0.76 0.06 0.01 0.1 34.9 16741.9 1.7 0.050.18 1.29 0.13 1.13 0.11 1.05 0.12 0.04 0.3 151.6 72787.8 2.7 0.110.26 1.59 0.23 1.39 0.16 1.25 0.18 0.10 0.8 353.1 169470.1 3.5 0.190.35 1.85 0.34 1.62 0.21 1.40 0.24 0.17 1.4 636.1 305306.0 4.1 0.270.44 2.09 0.47 1.83 0.26 1.52 0.31 0.26 2.2 994.9 477569.2 4.7 0.350.53 2.32 0.61 2.03 0.30 1.60 0.38 0.37 3.2 1422.4 682739.9 5.2 0.420.61 2.53 0.75 2.22 0.34 1.67 0.45 0.50 4.3 1909.8 916705.4 5.7 0.500.70 2.74 0.90 2.40 0.37 1.71 0.52 0.65 5.5 2447.6 1174863.8 6.1 0.570.79 2.94 1.05 2.57 0.41 1.74 0.60 0.82 6.7 3025.4 1452176.1 6.4 0.640.88 3.14 1.20 2.75 0.44 1.75 0.69 1.00 8.1 3631.6 1743184.7 6.7 0.700.96 3.34 1.36 2.92 0.46 1.74 0.78 1.20 9.5 4254.2 2042004.7 7.0 0.761.05 3.54 1.51 3.10 0.49 1.71 0.88 1.41 10.9 4879.8 2342283.1 7.2 0.811.14 3.75 1.66 3.28 0.50 1.67 0.99 1.65 12.2 5494.0 2637119.2 7.4 0.851.23 3.96 1.80 3.47 0.52 1.60 1.12 1.90 13.5 6081.1 2918919.8 7.5 0.881.31 4.19 1.94 3.67 0.53 1.52 1.28 2.19 14.8 6623.2 3179142.5 7.6 0.901.40 4.43 2.06 3.88 0.53 1.40 1.47 2.50 15.8 7099.6 3407810.7 7.7 0.911.49 4.69 2.18 4.11 0.53 1.25 1.74 2.88 16.7 7484.4 3592496.0 7.7 0.911.58 5.00 2.28 4.37 0.52 1.05 2.17 3.36 17.2 7741.2 3715763.3 7.6 0.891.66 5.38 2.36 4.71 0.50 0.76 3.09 4.15 17.4 7804.5 3746154.7 7.4 0.841.75 6.28 2.41 5.50 0.44 0.00 16.2 7265.7 3487548.2 6.7 0.70 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 0.00 0.50 1.00 1.50 2.00 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA PIPE G2 Gran Cielo Subdivision PH2 CIRCULAR CHANNEL Manning's Eqn.1.486 A R2/3 S1/2 n Diameter,do (in) =15 Enter Value Diameter,do (ft) =1.25 Units =1.486 n =0.009 PVC Slope, S (ft/ft)0.0158 Depth, y (ft) Theta (rad) Area, A (ft2) Wetted Perimeter, P (ft) Hydraulic Radius, R (ft) Top Width, T (ft) Hydraulic Depth, D (ft) Section Factor, Z (ft5/2) Q (cfs) Q (gpm) Q (gpd - 8 hour day) V (ft/s) Energy, E = V2/2g (ft) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0 0.0 0.0 0.00 0.06 0.90 0.02 0.56 0.04 0.54 0.04 0.00 0.1 25.3 12133.2 2.5 0.09 0.13 1.29 0.06 0.80 0.08 0.75 0.09 0.02 0.2 109.9 52750.6 3.8 0.23 0.19 1.59 0.12 0.99 0.12 0.89 0.13 0.04 0.6 255.9 122818.0 4.9 0.38 0.25 1.85 0.17 1.16 0.15 1.00 0.17 0.07 1.0 461.0 221260.6 5.9 0.54 0.31 2.09 0.24 1.31 0.18 1.08 0.22 0.11 1.6 721.0 346102.8 6.7 0.70 0.38 2.32 0.31 1.45 0.21 1.15 0.27 0.16 2.3 1030.8 494793.6 7.4 0.85 0.44 2.53 0.38 1.58 0.24 1.19 0.32 0.22 3.1 1384.1 664352.5 8.1 1.01 0.50 2.74 0.46 1.71 0.27 1.22 0.37 0.28 4.0 1773.8 851444.5 8.6 1.15 0.56 2.94 0.54 1.84 0.29 1.24 0.43 0.35 4.9 2192.5 1052417.5 9.1 1.29 0.63 3.14 0.61 1.96 0.31 1.25 0.49 0.43 5.9 2631.9 1263316.6 9.6 1.42 0.69 3.34 0.69 2.09 0.33 1.24 0.56 0.52 6.9 3083.1 1479876.6 9.9 1.53 0.75 3.54 0.77 2.22 0.35 1.22 0.63 0.61 7.9 3536.4 1697493.7 10.2 1.63 0.81 3.75 0.84 2.34 0.36 1.19 0.71 0.71 8.9 3981.6 1911166.6 10.5 1.71 0.88 3.96 0.92 2.48 0.37 1.15 0.80 0.82 9.8 4407.1 2115392.4 10.7 1.78 0.94 4.19 0.99 2.62 0.38 1.08 0.91 0.94 10.7 4800.0 2303980.4 10.8 1.82 1.00 4.43 1.05 2.77 0.38 1.00 1.05 1.08 11.5 5145.2 2469700.2 10.9 1.84 1.06 4.69 1.11 2.93 0.38 0.89 1.25 1.24 12.1 5424.1 2603544.9 10.9 1.84 1.13 5.00 1.16 3.12 0.37 0.75 1.55 1.45 12.5 5610.2 2692878.9 10.7 1.79 1.19 5.38 1.20 3.36 0.36 0.54 2.21 1.79 12.6 5656.1 2714904.0 10.5 1.701.25 6.28 1.23 3.93 0.31 0.00 11.7 5265.6 2527487.4 9.6 1.42 Q = 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 Depth (ft) Q (CFS) V (ft/s) E (ft)ydoT THETA Appendix C: Detention Pond Calculations Gran Cielo Phase 2 SubdivisionBennet Pond Calculations Calculation of Required Volume for Storm Detention Pond (Reference: Bozeman Stormwater Master Plan - 1982) Design Rainfall Freq.10 year (see page III - 5 of master plan)IDF coefficient a 0.64IDF coefficient bIDF coefficient n 0.65 Pre-development Calculations Post-development CalculationsCArea (AC)C Areas (ft2):open space 958,320 0.20 Areas (AC):Basin 6 3.65 0.38Basin 7 1.46 0.56Basin 8 4.15 0.49Basin 9 1.63 0.48Basin 13 10.17 0.46 Total:958,320 Total:21.06 total area:22.00 acres total area:21.06 acrescomposite C:0.20 composite C:0.46Overland tc Overland tcaverage slope:1.66 percent average slope:1.7 percent travel distance:1345 feet travel distance:1868 feettc:52 minutes tc:43 minutes Channel tc Channel tcchannel tc:minutes channel tc:minutes Total tc:52 minutes Total tc:43 minutes intensity at tc (fig 23):0.70 in/hr intensity at tc (fig 23):0.79 in/hr pre-devel peak runoff:3.09 cfs post-devel peak runoff:7.72 cfs Storm Duration Intensity Future Runoff Runoff Release Required(minutes)(in/hr)Rate (cfs)Volume (cf)Volume (cf)Storage (cf)25 1.13 11.01 16520 4628 11891 27 1.08 10.48 16971 4999 11972291.03 10.00 17400 5369 12032 31 0.98 9.58 17811 5739 12072330.94 9.19 18205 6109 12096350.91 8.85 18584 6480 12105370.88 8.54 18949 6850 12099390.85 8.25 19301 7220 12081 41 0.82 7.98 19642 7590 12052430.79 7.74 19972 7961 12012 45 0.77 7.52 20293 8331 11962470.75 7.31 20604 8701 11903490.73 7.11 20907 9071 11835510.71 6.93 21202 9442 11760530.69 6.76 21489 9812 11677550.68 6.60 21769 10182 11587570.66 6.45 22043 10552 11491 required detention storage (ft3) =12,105 Detention Pond Calculations:0.5 Inch Stormwater in Roadways Calculations:C design depth of pond 1.50 feet Areas (ft2):asphalt 209,337 0.90max side slope 4.00 horizontal to 1.00 vertical Includes roadways length/width ratio 3.00 A =4.81 acres min. particle removed 40 microns (1 micron = 1 x 10-6 meters)I = 0.021 in/hr (0.5" in 24 hrs)settling velocity of particle 0.0069 feet/second C =0.90Q = 0.09 cfsmin. pond to settle particle 1119 square feet Volume = 7,785 cfbottom weir h =1.00 ftpond dimentions assuming vertical side slopes (actual pond footprint will be larger)width 52 length 156 Volume held between contours:Cumulative Contour Area (ft2)Delta V (ft3)Volume (ft3) 4949.75 7,0704950.25 7,770 3,710 3,710 4950.75 8,502 4,068 7,7784951.25 9,266 4,442 12,220 Design storage at 1.5' depth (ft3) =12,220 Flow Structure Calculations - Bennet Pond (Reference: City of Bozeman, Design Standards and Specifications Policy, March 2004, II.D.2, page 24) Note: see Figure A-2 in above reference. Rectangular weir - Q=3.33LH3/2 Determine Outlet Slot Width needed: Pre-development flow rate = 3.09 cfs Vertical Slot Height = 6 inches Req'd Outlet Slot Width = 2.62 feet or 31 14/32 of an inch Determine Outlet Flow: Outlet Slot Width = 31.45 inches Stage above pond btm. ft stage above weir (ft)Q (cfs)Q (gpm) 1.00 0.00 0.000 01.10 0.10 0.276 124 1.20 0.20 0.781 350 1.30 0.30 1.434 644 1.40 0.40 2.208 991 1.50 0.50 3.086 1385 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 0.00 0.10 0.20 0.30 0.40 0.50 0.60Discharge (cfs)Stage (ft) Flow through outletStage vs. Discharge Gran Cielo Phase 2 SubdivisionApex Pond Calculations Calculation of Required Volume for Storm Detention Pond (Reference: Bozeman Stormwater Master Plan - 1982) Design Rainfall Freq.10 year (see page III - 5 of master plan)IDF coefficient a 0.64IDF coefficient bIDF coefficient n 0.65 Pre-development Calculations Post-development CalculationsC C Areas (ft2):open space 396,614 0.20 Areas (ac):Basin 2 0.55 0.67Basin 12 0.41 0.67Basin 16 0.83 0.67Basin 17 0.72 0.67Basin 18 8.98 0.54 Total:398,138 Total:11.49 total area:9.14 acres total area:11.49 acrescomposite C:0.20 composite C:0.57 Overland tc Overland tcaverage slope:1.25 percent average slope:1.25 percenttravel distance:700 feet travel distance:1042 feet tc:41 minutes tc:30 minutes Channel tc Channel tcchannel tc:minutes channel tc:minutes Total tc:41 minutes Total tc:30 minutes intensity at tc (fig 23):0.81 in/hr intensity at tc (fig 23):1.01 in/hr pre-devel peak runoff:1.48 cfs post-devel peak runoff:6.56 cfs Storm Duration Intensity Future Runoff Runoff Release Required(minutes)(in/hr)Rate (cfs)Volume (cf)Volume (cf)Storage (cf)34 0.93 6.03 12300 3027 9272360.89 5.81 12548 3205 9343 38 0.86 5.61 12788 3384 9404400.83 5.42 13020 3562 9458 42 0.81 5.26 13244 3740 9504440.78 5.10 13461 3918 9544460.76 4.95 13672 4096 9577 48 0.74 4.82 13878 4274 9604500.72 4.69 14077 4452 9625 52 0.70 4.57 14272 4630 9642540.69 4.46 14462 4808 9653 56 0.67 4.36 14647 4986 9661580.65 4.26 14828 5164 9664600.64 4.17 15005 5342 9662620.63 4.08 15178 5520 9658640.61 4.00 15348 5699 9649660.60 3.92 15514 5877 9637 required detention storage (ft3) =9,664 Detention Pond Calculations:0.5 Inch Stormwater in Roadways Calculations: C design depth of pond 1.50 feet Areas (ft2):asphalt 162,589 0.90max side slope 4.00 horizontal to 1.00 verticallength/width ratio 3.00 A =3.73 acres min. particle removed 40 microns (1 micron = 1 x 10-6 meters)I = 0.021 in/hr (0.5" in 24 hrs) settling velocity of particle 0.0069 feet/second C =0.90Q = 0.07 cfsmin. pond to settle particle 950 square feet Volume = 6,047 cfbottom weir h =0.99 ftpond dimentions assuming vertical side slopes (actual pond footprint will be larger)width 46length139 Volume held between contours:Cumulative Contour Area (ft2)Delta V (ft3)Volume (ft3)4941.50 5,449 4942.0 6,104 2,888 2,8884942.5 6,791 3,224 6,112 4943.0 7,507 3,575 9,687 Design storage at 1.5' depth (ft3) =9,687 Flow Structure Calculations - Apex Pond (Reference: City of Bozeman, Design Standards and Specifications Policy, March 2004, II.D.2, page 24) Note: see Figure A-2 in above reference. Rectangular weir - Q=3.33LH3/2 Determine Outlet Slot Width needed: Pre-development flow rate = 1.48 cfsVertical Slot Height = 6.12 inchesReq'd Outlet Slot Width = 1.22 feet or 14 22/32 of an inch Determine Outlet Flow: Outlet Slot Width = 14.68 inchesstage above pond btm. Ft stage above weir (ft)Q (cfs)Q (gpm) 0.99 0 0.000 0 1 0.01 0.004 2 1.1 0.11 0.149 671.2 0.21 0.392 1761.3 0.31 0.703 316 1.4 0.41 1.070 480 1.5 0.51 1.484 666 -0.20 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 0 0.1 0.2 0.3 0.4 0.5 0.6Discharge (cfs)Stage (ft) Flow through outletStage vs. Discharge Appendix D: Groundwater Monitoring Information Gran Cielo Subdivision Groundwater Depth Summary Table Well 8/8/2017 8/25/2017 9/8/2017 10/2/2017 10/16/2017 10/30/2017 11/29/2017 12/29/2017 2/12/2018 4/11/2018 5/7/2018 5/14/2018 5/21/2018 5/29/2018 6/6/2018 6/11/2018 6/18/2018 6/27/2018 7/2/2018 7/13/2018 8/15/2018 #2 4.70 4.75 5.07 4.37 4.60 5.14 4.31 5.20 4.87 2.18 3.29 3.64 4.12 4.27 4.33 4.71 4.99 4.66 DNF DNF 5.57 #3 4.41 4.19 4.49 3.60 3.40 4.21 3.27 4.14 3.72 1.45 2.70 2.96 3.42 3.52 3.57 3.96 4.17 3.32 3.50 3.58 4.31 #5 2.27 2.60 2.82 1.66 2.07 2.65 2.02 2.58 2.18 3.98 1.87 1.98 2.24 2.22 2.28 2.52 2.56 2.15 2.22 2.43 2.54 #6 3.82 3.46 3.84 2.71 2.84 3.09 2.21 2.98 2.50 1.22 2.20 2.32 2.72 2.64 2.76 3.12 3.17 2.70 2.72 3.25 3.79 #8 1.50 3.61 3.39 3.07 3.69 4.49 3.97 4.63 4.29 1.70 2.92 3.27 3.57 3.74 4.11 4.14 4.02 3.29 3.47 3.50 3.18 #10 2.60 4.29 4.44 4.34 4.92 5.67 5.56 DNF DNF 2.51 3.36 3.85 4.10 4.38 4.47 4.88 4.92 4.86 3.55 3.55 4.89 #13 3.66 3.70 4.03 3.89 3.85 4.32 3.97 4.66 4.71 0.54 1.65 1.83 2.79 3.09 3.22 3.64 3.30 3.18 DNF DNF DNF #15 4.57 5.04 5.28 5.35 5.55 6.05 6.17 6.68 6.80 1.88 2.94 3.69 4.32 4.74 4.99 5.25 5.33 4.24 4.29 4.00 4.65 DNF Did Not Find Appendix E: Manning’s N Documentation Appendix F: Excerpts from Phase 1 Stormwater Report Appendix G: Stormwater Maintenance Plan G:\MADISON ENGINEERING\PROJECTS\2017\17-130 Canvasback\Reports\Stormwater Management\Phase 2\STORMWATER MAINTENANCE PLAN.doc STORMWATER MAINTENANCE PLAN Gran Cielo Subdivision Phase 2 Home Owner’s Association responsibility for routine inspection and maintenance 1. Keep the curb & gutter, inlets, pipes, outlets and swales of the facility free of leaves, rocks, sediment buildup, and other debris. 2. The storm water detention basins are to be mowed regularly. During the summer, approximately once every two weeks, the grass is to be mowed and the cuttings are to be promptly removed and disposed of. Unless visibly tainted, dispose of lawn clippings in the same manner as yard waste. Otherwise, bag and take to a sanitary landfill. 3. Remove sediment within the ponds by hand with a flat bottom shovel during the summer months whenever sediment covers vegetation. Have the grass cut short in that particular location so that the bed can be made as level as possible. 4. Re-sod damaged or maintained areas immediately, or use grass plugs from the adjacent up-slope area. 5. Inspect the facilities periodically, especially after heavy rains (preferably monthly and after each storm that delivers 0.5 inches of rainfall). 6. Inspect curb inlets, storm drain manholes, and flow control outlet structures semi- annually. Remove sediment within sumps and clean outlets when soil and vegetation buildup interfere with flow introduction. 7. Home Owner’s Association to maintain and fund Operation and Maintenance of stormwater facilities. _______________________________ Home Owner’s Association H.4 – Gran Cielo Subdivision, Phase 2 As-Builts