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HomeMy WebLinkAboutEverhome Storm ReportPage 1 of 5 Storm Drainage Calculations Bozeman Gateway – Site A Everhome February 7, 2022 1 Introduction This summary report provides hydrologic and hydraulic calculations for sizing of detention storage facilities and other storm drainage structures for development of the Bozeman Gateway Phase 5 Lots 1 & 2, in accordance with the City of Bozeman Design Standards. The proposed site consists of a hotel and a fast food restaurant located northwest of the intersection of Fowler Ave. and Technology Blvd West. Pre-development topography is gradual, about 1 to 2 percent slope from south to north. Existing ground cover is undeveloped, previously agricultural fields. The purpose of the report and calculations is to demonstrate the following: - Post- development peak runoff does not exceed pre-construction (historic) conditions for the 10-year storm event - The 25-year peak runoff is conveyed by underground storm drain facility with no surface overflow - Storm water treatment is provided to intercept and contain sediment and floating debris on site, for eventual removal and disposal. 2 Drainage Patterns Existing Conditions – On Site Flows The existing site includes a drainage area of approximately 5.42 acres (236,196 ft2). The pre-development, existing (historic) runoff is illustrated on Figure 1 (Pre-Development Drainage Map). Runoff for Basin H1 drains to the west off the property and is eventually piped north across Huffine. Runoff from H2 drains to the east and is collected in an existing 31”x51” concrete arch pipe (RCPA) storm drain culvert with conveyance north across Huffine. Existing Conditions – Off Site Flows Rosauers and Building F Flows Flows from the Bozeman Gateway Phase 1 development contribute to the offsite flows onto Phase 5 during larger storms. The previously approved drainage submittals for the associated Phase 1 projects are attached and highlighted in Appendix A. - Bozeman Gateway – Phase 1, Block 2 (May 2, 2006) - Bozeman Gateway – Building F Site Plan (June 19, 2014) The Storm Drainage Calculations for Bozeman Gateway Phase 1, Block 2 indicate that runoff from Sub-basins 1.1 and 1.2 is collected at the northwest corner of Phase 1, crossing under Fowler Ave. through a 30” concrete arch pipe (see Figure 3 from Bozeman Gateway – Phase 1, Block 2). These flows are then conveyed north under Huffine Lane by the existing 31”x51” RCPA culvert under Huffine Lane. Additionally, Sub-basin D1.3, south of Technology Boulevard west, drains to a proposed underground detention facility which discharges into an existing storm drain under Page 2 of 5 Technology Boulevard West and through the Rosauers storm drain. The contributing area from Sub-basin D1.3 is shown in Fig 2 of the Bozeman Gateway – Building F Site Plan. The total offsite flows from Bozeman Gateway Phase 1 will be used to evaluate the capacity of the Huffine Culvert during the 25-year storm event. Based on the previously approved storm reports the 25-year flows for Sub-basin 1.1 is 9.21cfs, Sub-basin 1.2 is 12.26cfs and Sub-basin D1.3 is 4.36cfs, for a total 25-year peak runoff of 25.83 cfs. This is a conservatively high estimate because there is a small amount of overlap between Rosauers sub-basin D1.2 and Site F sub-basin D-3. Irrigation Flow There are two existing head gates that convey Farmers Canal irrigation flows north through existing on-site drainage ditches to discharge through the existing 31”x51” RCPA culvert under Huffine Lane. The Montana Bureau of Mines and Geology has monitored the flow in the Farmer’s canal ditch at the location of the head gates from June of 2017 to October 2018. The maximum combined rate that could discharge to the Site A irrigation ditch from these measurements was 21.41cfs on June 2017. This offsite flow rate will be used to conservatively estimate the 25-year conveyance calculations for Site A. Existing Pond The existing pond in Phase 5 has been designed to detain flows from the North portion of Fowler Street. The flows from the outlet structure in this existing pond will be used to evaluate the 25-year conveyance for the Huffine culvert. The 25-year conveyance from Fowler was calculated to be 3.12 cfs; see calculations in Appendix B. Proposed Improvements: The proposed site development is to include a system of storm drainage inlets, sidewalk chases, piping, and subsurface storm water detention systems. Post-development runoff is illustrated on Figure 2 (Post development Drainage Map). Runoff from sub-basins D1, D2.3a and D2.3b cannot be intercepted onsite; these areas drain offsite as direct runoff, similar to existing conditions. Sub-basin D2.1 drains into an underground detention system located in the northern portion of D2.1. Sub-basin D2.2 drains into an underground detention system located in the northern portion of D2.2. Runoff from sub- basin D2.4 will be treated by a retention pond located within the adjacent open space in Basin D2.3a and was addressed as a part of the Phase 5 Infrastructure plans. Sub-basins are linked by surface or piped overflow to allow excess runoff to continue downstream without flooding surface improvements. Runoff in excess of detention volumes is routed downstream. To address City of Bozeman development standards, 25-year peak runoff flows offsite via underground piping to the existing culvert underneath Huffine Lane. 3 Approach It will be shown that proposed detention and treatment facilities will limit the post- development 10-year peak runoff rate of Phase 5 to the pre-development rate and will provide effective treatment of storm runoff. All storm drain pipes have been sized to convey the 25-year peak runoff. Page 3 of 5 The Rational Method was used to calculate peak runoff and detention requirements in accordance with City of Bozeman design standards. The peak runoff table (Appendix B) is an Excel spreadsheet with formulas that calculate post-development discharge values. The values used in each column of the table are as follows: Area Calculated in AutoCAD from Figures 1 and 2 C (Rational Method runoff coefficient): Runoff coefficients were calculated using 0.20 for pervious areas (pre-development and developed landscape areas) and 0.90 for impervious areas (pavement, concrete and rooftops). Pro-rating by area resulted in the coefficients used in the calculations. Tc (time of concentration) Five minutes is the minimum value used in the Rational Method. Some of the smaller sub-basins would calculate to less than 5 minutes. Peak Runoff Values (Q2 through Q100) Values were calculated using the Rational Method formula (Q = CiA) and the intensity formulas in the City’s design standards (Rainfall Intensity – Duration Curves) 3 Detention and Retention Facilities For the 10-year design storm, post-development peak flows and detention volumes are estimated using the Rational Method in accordance with City of Bozeman Design Standards. Sub-basins D2.1 and D2.2 will drain to “StormTech” pre-fabricated underground storage and infiltration systems. The StormTech system will include an inlet manhole that doubles as access for cleaning the isolator (sediment accumulation) row of the system. Sub-basin D2.1 The detention facility for Sub-basin D2.1 will discharge through a 12” PVC pipe to a control structure housed in a manhole. The detention outlet control structure will consist of a vertical tee with a 1¼” diameter (or a 13/16” square) orifice on the bottom and an 18” diameter vertical riser to pass runoff exceeding the 10-year storage maximum water surface elevation into the piped storm drain system. The top of the overflow riser will be set at elevation level with the top of the 36” storage depth (top of stone backfill). Excess runoff from larger, less frequent storm events will overtop the vertical tee, to the 25-year maximum depth indicated in Table 1. Sub-basin D2.2 The detention facility for sub-basins D2.2 will discharge through a 15” pipe to a control structure house in a manhole. The control structure for this detention facility will consist of a 18” diameter vertical tee with a 1 ¾” diameter (or a 15/8” square) orifice cut into an end cap on the bottom of the tee; the orifice will limit 10-year peak runoff to the required maximum rate. Like Sub-Basin D.2.1, the top of the vertical tee will act as an overflow riser and will be cut horizontally to an elevation level with the top of the 36” storage depth (top of stone backfill). Page 4 of 5 The control structure and discharge piping for each facility will convey the 25-year peak runoff to the existing culvert that crosses north on Huffine. Detention volume and pipe sizing calculations are attached in Appendix B. Design details will be provided on the construction drawings. Sub-basin D2.4 4 Conveyance The storm drain piping system for the proposed development is designed to convey flows from a 25-year storm. See Appendix C for the conveyance calculations for the storm drain pipes and culverts within Phase 5. Huffine Culvert Almost all of Phase 5 along with other offsite flows mentioned in the existing conditions section of this report will drain to the culvert crossing Huffine to the north. If on-site detention effects are ignored in a 25-year storm event, the 25-year peak runoff to the Huffine culvert can be estimated by adding the flow from Basins 2.1, 2.2 and 2.4, direct flow from Phase 5, flow from the farmers canal and the offsite flows from Rosauers, Building F and the existing pond for Fowler Ave: Q25 (Basins 2.1, 2.2 and 2.4) = 2.96 + 6.32 + 1.73 = 11.01cfs Q25 (direct flow – Basins D2.3a + D2.3b) = 0.54 cfs Q25 (Farmers Canal) = 21.41cfs Q25 (offsite flows) = 9.21 + 12.26 + 4.36 + 3.12 = 28.95cfs Q25 (total to Huffine culvert) = 11.01 + 0.54 + 21.41 + 28.95 = 61.91cfs The calculations in Appendix C illustrate that the Huffine culvert can convey the 25-year peak runoff (61.91 cfs) without flooding the site. For the Huffine culvert, the equivalent pipe size of 42” diameter was used to model the 31”x51” arch pipe. In the case of a 100- year storm, stormwater would overtop Huffine Lane on the west side of the property. 5 Storm Water Treatment The City’s design standards require Low Impact Development (LID) practices that infiltrate, evapotranspire or capture runoff, to the extent feasible, for a specified design runoff event. This requirement is addressed using existing and proposed StormTech underground detention and storage facilities. These systems combine infiltration and runoff capture. The StormTech system is a widely accepted LID practice found to remove 80 percent of total suspended solids from municipal storm runoff. It meets LEED criteria for storm water treatment (SS6.2 water quality credit). The facilities for this project provide over 6 inches of capture depth for infiltration and runoff volume reduction, plus treatment of additional runoff by deposition as water slowly travels through the long, linear rows of chambers and gravel base. The system solves the problem of runoff “short-circuiting” from inlet to outlet that is inherent in surface detention ponds. Runoff from the first ½” of rainfall will percolate through and fill a gravel filter before finding its way to a perforated low-flow outlet pipe that discharges into the detention outlet structure. Additional runoff from larger storms can bypass this discharge route, but only after storage depth reaches 2 feet (this correlates to about 64 percent of the total available storage volume). Although the detention calculations assume zero Page 5 of 5 infiltration, the existing alluvial (gravel/pit run) soils directly under the StormTech systems provide excellent infiltration, which further improves treatment. We believe this type of treatment not only meets, but exceeds, the City’s current design standards. 6 Groundwater Existing Monitoring well #231832 (IR-1) was measured on August 5, 2021 to estimate the high water in this area. The water level was 14.28ft below the top of the well casing which has an elevation of 4846.652. Therefore the groundwater at this existing well is 4832.37. Both of the storm tech detention systems have a bottom elevation over 3’ above the estimated high groundwater level. Given that the groundwater also slopes away to the north it is assumed that the groundwater below the detention systems will be even lower than at IR-1. 7 Results Summary The proposed detention and retention facilities will treat runoff from sub-basins D2.1 and D2.2 under fully developed conditions. These two sub-basins include all of the proposed impervious area except the pedestrian trail along Fowler Avenue. The detention facilities will limit the 10-year maximum release rate from the site, to ensure that the total post-development peak runoff rate does not exceed the pre-development 10-year peak runoff rate in either basin (D1 draining east, or D2 draining north). In basin D1, the 10-year post-development peak runoff rate (sub-basin D1) is 0.08 cfs, which is less than the 0.14 cfs of existing Basin H1. In basin D2, the total 10-year post-development peak runoff from “direct runoff” sub-basins D2.3a and D2.3b (0.33 cfs see Appendix B), plus the total 10-year peak discharge from the two underground facilities (0.38 cfs, see Table 1 below) is 0.71 cfs; this is equal to the pre-development 10-year peak runoff rate of sub-basin H2. Therefore, the total post-development 10-year peak runoff rate does not exceed the pre-development rate. TABLE 1 - Detention Basin Data Description Basin Name D2.1 D2.2 Max. 10-yr Release Rate (cfs) 0.08 0.30 Min. Required Detention Volume (cu. ft.) 1,881 3,666 Design System Detention Volume (cu. ft.) Sizes and Dimensions: vertical tee (riser) dia., inches 18 18 outlet pipe dia., inches 12 12 Orifice (two alternates): circular orifice dia., inches 11/4 13/4 rectangular (proposed replacement) 13/16 x 13/16 15/8 x 15/8 Elevations: 25-yr WSEL at control structure 40.09 40.19 top of riser (=10-yr max. WSEL) 39.76 39.57 discharge pipe invert at control structure 36.76 36.57 E E E E E FO FO FO FO H10.94 Ac.H24.48 Ac.4840484548364836483748374838483848394841484248434 8 4 448464847 48464847484848494846484 7 48474848 48 4 8306015300SCALE IN FEETFIGURE NUMBER©PROJECT NO.DRAWN BY:DSGN. BY:APPR. BY:DATE:COPYRIGHT MORRISON-MAIERLE, INC.,2020N:\3638\009\ACAD\Site Plans\Building-A\Exhibits\Strom Report Exhibits\3638009 Fig 03 Existing Drainage Basins.dwg Plotted by celine saucier onJun/15/2020engineers surveyors planners scientistsMorrisonMaierle2880 Technology Blvd WestBozeman, MT 59718406.587.0721www.m-m.net3638.009FIG 1BOZEMAN GATEWAY PUD - PHASE 5BOZEMANMONTANAPREDEVELOPMENT DRAINAGE MAPCMSJAUJAU06/2020PRECAST CONCRETEDIVERSION STRUCTUREINV IN = 4843.60INV OUT = 4843.60 (E)INV OUT = 4844.10 (N)6X8" PRECAST CONCRETEVAULT INV IN = 4841.22INV OUT = 4841.12108LF 48"ARCP ARCH PIPEINV IN = 4843.60INV OUT = 4841.22SLOPE 2.20%132 LF OF 72" ARCP W/FLARED END SECTIONSAND TRASH RACKSINV IN = 4844.94INV OUT = 4844.77SLOPE = 0.13%124 LF OF 15" RCP W/FLARED END SECTIONSBOTH SIDESINV IN = 4848.38INV OUT = 4847.15SLOPE = 1.0%180 LF 30" ARCPW/ FLARED END SECTIONWEST SIDEINV IN - 4835.54INV OUT = 4835.00SLOPE = 0.3%106 LF 15" RCPW/ FLARED END SECTIONWEST SIDEINV IN = 4836.31INV OUT = 4835.25SLOPE = 1.0%POND #3 VOL = 1213 CFWATER SURFACE EL = 4836.75TOP OF BANK EL 4837 TO 4837.25POND BOTTOM 4835.25SIDE SLOPE = 3:1EXISTING 31" X 51" ARCP@ 0.74% SLOPE D2.22.15 Ac.D2.10.92 Ac.D2.40.41 Ac.D2.3b0.73 Ac.D2.3a0.57 Ac.D10.47 Ac.SSSSSSSSSSSS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS SS W W W W W W W W W W W W W W W W W W W W W W W W W W W W SSSSSSSSSSWWWWWWWWWWWW306015300SCALE IN FEETFIGURE NUMBER©PROJECT NO.DRAWN BY:DSGN. BY:APPR. BY:DATE:COPYRIGHT MORRISON-MAIERLE, INC.,2022N:\3638\009\ACAD\Site Plans\Building-A\Everhome\Exhibits\Strom Report Exhibits\3638009 Fig 04 Postdevelopment Drainage Areas - Everhome.dwgPlotted by celine saucier on Feb/8/2022engineers surveyors planners scientistsMorrisonMaierle2880 Technology Blvd WestBozeman, MT 59718406.587.0721www.m-m.net3638.009FIG 2BOZEMAN GATEWAY PUD - PHASE 5BOZEMANMONTANAPOSTDEVELOPMENT BASINCMSJAUJAU06/202015" RCP W/ FLARED ENDSECTION WEST SIDEINV IN = 4836.31INV OUT = 4835.25SLOPE = 1.0%EXISTING PONDWATER SURFACE EL: 4836.25POND BOTTOM 4835.25EXISTING 22.5" X 36.25 ARCP64.55 LF 24" CULVERT@ 0.5% SLOPEINV IN: 4843.45INV OUT: 4843.1370.1' LF 36" CULVERT@ 0% SLOPEINV IN: 4842.93INV OUT: 4842.93CULVERT #165.3LF 30"@ 1.5 % SLOPEINV IN: 4841.14INV OUT: 4840.16CULVERT #348.88LF 30"@ 2.6% SLOPEINV IN: 4838.6INV OUT: 4837.3EXISTING 31" X 51" ARCP@ 0.74% SLOPECULVERT #349.7LF 42"@ 1.4% SLOPEINV IN: 4834.85INV OUT: 4834.13PROPOSED EAST STORMTECH DETENTIONSYSTEMPROPOSED NORTHSTORM TECH DETENTIONSYSTEM SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSWWWWWWWWWWWWWWWWWWSSSSSSWW W W W W SSSSSSSSSSSSSSSSN0°19'02"W 591.97'R =5 0.00' L=7 8 .51 'Δ=89 °58'11"S0°00'00"E 267.01'>>>>>>>>>>>>>>>> 4838 48394840 4841 48424842484148 414842484148394839483848374834 4835 483648374838483948394838483848374836484048414842484048414842484248414840484148414842484348444838 4839 48 4 0 4841 484 4 48 4 5 48 4 348424839 42.81 42.56 42.56 42.81 42.13 41.92 41.92 42.13 41.24 41.10 40.86 40.76 40.86 41.03 41.92 41.75 42.16 43.51 43.77 43.94 41.97 45.79 42.35 42.12 42.30 42.25 41.87 41.8942.15 42.2742.36 42.19 42.13 41.81 41.68 41.76 41.9141.53 41.40 41.40 41.64 41.96 41.82 41.82 41.96 42.41 42.23 42.27 42.37 42.08 -1.59 % -1.92%-1.11 % -1.26 % -1.38 % -1.75%-1.04%-1.04%-1 .75% -4 .26%-3.82%-3.32% -2.74 % -2.78% -0 . 6 3% -2.69 %-1.75% 4841 -0.81%-1.00%-1.75%-0.92%-1.49%-1.99%0.49%-1.45%-0.51%-1.00 %-1.54 % -1.54 %-0.93%4842-1.83% 20 4010200 SCALE IN FEET 21.4 LF OF 12" PVC STORM PIPE @ 1.0% SLOPE 64.3LF OF 18" PVC STORM PIPE @ 1.15% SLOPE 47.2 LF OF 18" PVC STORM PIPE @ 3.7% SLOPE CULVERT #2 48.88 LF 30" @ 2.6% SLOPE INV IN: 4838.6 INV OUT: 4837.3 GENERAL NOTES 1.ALL STORM DRAIN MANHOLES SHALL BE 48-INCH DIAMETER, CONSTRUCTED PER CITY OF BOZEMAN STANDARD DETAILS. MANHOLES INDICATING “RIM=” SHALL HAVE SOLID COVERS, THOSE INDICATING “GRATE=” SHALL HAVE SLOTTED (GRATED) COVERS, AND THOSE INDICATING “TBC=” SHALL HAVE CURB INLET TYPE SLOTTED COVERS. 2.SPOT ELEVATIONS ALONG CURB LINES AND SIDEWALK EDGES ARE TOP BACK OF CURB (TBC) AND TOP OF SIDEWALK ELEVATIONS. SUBTRACT 0.50' (SPILL CURB) OR 0.37' (CATCH CURB) TO OBTAIN EDGE OF GUTTER (EG) ELEVATION AT THE ASPHALT/GUTTER LINE. 3.GRADE BREAK LINES (SEE LEGEND): USE STRAIGHT-LINE INTERPOLATION TO DETERMINE FINISHED GRADE ELEVATIONS BETWEEN INDICATED SPOT ELEVATIONS. T CATCH CURB SPILL CURB TRANSITION CURB (T) TOP BACK OF CURB ELEVATIONTBC EDGE OF GUTTER ELEVATIONEG LEGEND GRADE BREAK LINE (SEE NOTE 3) MATCH LINE C601 EXISTING 15" RCP W/ FLARED END SECTION WEST SIDE INV IN = 36.31 INV OUT = 35.25 SLOPE = 1.0% EXISTING POND TO BE RE-ESTABLISHED TOP: 37.25 WATER SURFACE EL: 36.25 POND BOTTOM 35.25 EXISTING 22.5" X 36.25 ARCP EXISTING 132LF OF 31" X 51" ARCP @ 0.74% SLOPE INV IN: 4832.99 INV OUT: 4832.01 EVERHOME HOTEL FFE: 4842.5 © 2880 Technology Blvd. W. Bozeman, MT 59718 Phone: (406) 587-0721 Fax: (406) 922-6702 SHEET NUMBER PROJECT NUMBER DRAWING NUMBER DRAWN BY: CHK'D. BY: APPR. BY: DATE: Q.A. REVIEW DATE: BY: COPYRIGHT MORRISON-MAIERLE, INC.,2022 VERIFY SCALE! THESE PRINTS MAY BE REDUCED. LINE BELOW MEASURES ONE INCH ON ORIGINAL DRAWING. MODIFY SCALE ACCORDINGLY! REVISIONS DATEDESCRIPTIONNO.BY N:\3638\009\ACAD\Site Plans\Building-A\Everhome\Sheets\3638.009 C600 Overall Grading Plan.dwg Plotted by celine saucier on Feb/8/2022 engineerssurveyorsplannersscientistsengineerssurveyorsplannersscientists 3638.009 7 C600 BOZEMAN MONTANA CMS JAU JAU 2/2022 EVERHOME HOTEL GRADING PLAN SITE "A" BOZEMAN GATEWAY PUD CULVERT #3 49.7 LF 42" RCP @ 1.4% SLOPE INV IN: 4834.85 INV OUT: 4834.13 1 UNDERGROUND STORM WATER DETENTION SYSTEM (27 CHAMBERS) 10 YEAR WATER SURFACE ELEV.= 4839.76 (TOP OF GRAVEL) BASE ELEVATION, CHAMBERS = 4836.76 (LEVEL) MAX SUB-GRADE ELEVATION = 4836.26* * EXCAVATE TO NATIVE GRAVEL LAYER TO ALLOW INFILTRATION 10-YEAR STORAGE VOL = 2,382CF ADS STORMTECH SC-740 CHAMBERS, OR APPROVED EQUAL. INSTALL A CONTINUOUS PIECE OF FABRIC IN TWO LAYERS UNDER CHAMBERS ALONG ENTIRE LENGTH OF SYSTEM. SEE SHEET C710 FOR ADDITIONAL REQUIREMENTS. 2 UNDERGROUND STORM WATER RETENTION SYSTEM 10 YEAR WATER SURFACE ELEV.= 4839.57 (TOP OF GRAVEL) BASE ELEVATION, CHAMBERS = 4836.57 (LEVEL) MAX SUB-GRADE ELEVATION = 4836.07* * EXCAVATE TO NATIVE GRAVEL LAYER TO ALLOW INFILTRATION 10-YEAR STORAGE VOL = 6,625CF ADS STORMTECH SC-740 CHAMBERS, OR APPROVED EQUAL. INSTALL A CONTINUOUS PIECE OF FABRIC IN TWO LAYERS UNDER CHAMBERS ALONG ENTIRE LENGTH OF SYSTEM. SEE SHEET C710 FOR ADDITIONAL REQUIREMENTS. 1 50.67 LF OF 12" STORM DRAIN @ 1% SLOPE INV OUT: 38.27 SEE PLUMBING FOR CONTINUATION 60.9 LF OF 12" PVC STORM PIPE @ 1.0% SLOPE .1 CI #1 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 40.76 12" INV OUT (SE) = 36.97 NOTES BY SYMBOL: 1 CI #2 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 40.53 12" INV OUT (W)= 37.37 2 2. SDMH #1 NEW 48"Ø STORM DRAIN MANHOLE RIM = 40.74 12" INV IN (NW) = 36.76 12" INV IN (SE) = 36.76 24" INV OUT (E)= 36.76 3 .3 4. 5. SDMH #2 NEW 48"Ø STORM DRAIN MANHOLE RIM = 41.43 12" INV IN (E) = 36.76 24" INV OUT (W)= 36.76 4 SDMH #3 NEW 48"Ø STORM DRAIN MANHOLE RIM = 41.01 6" INV IN (NW) = 36.76 12" INV IN (W)= 38.26 18" INV OUT (N) = 36.76 5 2 C700 2 64LF OF 15" PVC STORM PIPE @ 1.15% SLOPE 6 .6 7 .8 SDMH #4 NEW 48"Ø STORM DRAIN MANHOLE RIM = 39.87 15" INV IN (S) = 36.57 24" INV OUT (N)= 36.57 .7 CI #3 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 40.59 12" INV OUT (W)= 4836.72 8 3 C700 SDMH #5 NEW 48"Ø STORM DRAIN MANHOLE RIM = 39.87 6" INV IN (SW) = 36.57 12" INV IN (S) = 38.07 18" INV OUT (NW)= 36.57 SSSSSSSSSSSSSSSSSSSSSSSSWWWWWWWWWWWWWWWWSS W W SS SS SS SS SS W W W W W W SSSSSSSSSSSSSSSSSSSSSSSSSSSSW W W W W W W W W W W W W W W WSSWWWWWWWWWWWWWWWWWWWWWWWW W W W W W SSS83°52'34"W 200.48'S0°18'43"E 196.42'S89°41'43"W 27.21' N0°00'00"E 26.91' N90°00'00"E 25.13' N76°44'45"E 7 0 . 6 0 ' S75°49'16"E 22.12' S52°55'58"W 14.64' S68°31'4 9 " W 5 7 . 9 3' N90°00'00"W 28.49' R=569.01' L=49.86' Δ=5°01'15" 49.42 49.4749.30 49.75 48.58 48.4948.25 48.34 50.00 49.34 49.36 49.43 46.25 45.94 45.77 45.85 46.16 43.43 43.16 43.03 43.17 42.67 42.42 42.22 42.36 43.57 45.07 45.90 45.65 45.23 45.14 45.18 45.32 45.78 46.09 46.29 46.08 47.89 46.73 46.27 45.55 44.02 43.26 42.78 43.56 43.90 44.07 44.14 44.10 45.21 45.64 45.68 46.13 47.58 47.80 48.07 47.93 47.93 48.06 48.34 49.25 48.87 49.17 49.74 49.17 49.20 48.8648.89 44.80 47.70 47.63 44.86 45.86 46.14 47.03 47.22 46.75 46.54 46.34 44.91 45.06 44.9144.77 43.00 42.41 42.97 43.11 42.62 42.71 42.35 42.35 42.71 45.34 45.18 45.32 45.49 46.99 47.37 47.44 45.16 45.33 45.33 45.16 47.82 47.82 48.33 48.62 41.76 41.92 41.65 41.60 41.99 42.02 42.02 42.34 42.03 41.69 41.69 41.80 41.89 -4. 0 4 % -3.60% -1 .90%-2.02%-3 .24%-2.86%-1.71%-1.98%-3.76%-2.59%-3.67%-3.94%-3.56%-3.36%-2.82%-3.10%-3.67% -2.8 3 % -2.8 6 %-0.57%-0.69%-0.51%-0.94%-1.54%-0.71% 47.05 46.73 45.71 45.44 45.12 -0.97% 20 4010200 SCALE IN FEET 57.5LF OF 12" PVC STORM PIPE @ 1% SLOPE CULVERT #1 65.3 LF 30" @ 1.5% SLOPE INV IN: 4841.14 INV OUT: 4840.16 GENERAL NOTES 1.ALL STORM DRAIN MANHOLES SHALL BE 48-INCH DIAMETER, CONSTRUCTED PER CITY OF BOZEMAN STANDARD DETAILS. MANHOLES INDICATING “RIM=” SHALL HAVE SOLID COVERS, THOSE INDICATING “GRATE=” SHALL HAVE SLOTTED (GRATED) COVERS, AND THOSE INDICATING “TBC=” SHALL HAVE CURB INLET TYPE SLOTTED COVERS. 2.SPOT ELEVATIONS ALONG CURB LINES AND SIDEWALK EDGES ARE TOP BACK OF CURB (TBC) AND TOP OF SIDEWALK ELEVATIONS. SUBTRACT 0.50' (SPILL CURB) OR 0.37' (CATCH CURB) TO OBTAIN EDGE OF GUTTER (EG) ELEVATION AT THE ASPHALT/GUTTER LINE. 3.GRADE BREAK LINES (SEE LEGEND): USE STRAIGHT-LINE INTERPOLATION TO DETERMINE FINISHED GRADE ELEVATIONS BETWEEN INDICATED SPOT ELEVATIONS. T CATCH CURB SPILL CURB TRANSITION CURB (T) TOP BACK OF CURB ELEVATIONTBC EDGE OF GUTTER ELEVATIONEG LEGEND GRADE BREAK LINE (SEE NOTE 3) MATCH LINE C600 27.5LF OF 12" PVC STORM PIPE @ 1% SLOPE PROPOSED DRAINAGE SWALE PROPOSED DRAINAGE SWALE 30.2 LF OF 15" HDPE STORM PIPE @ 1% SLOPE FFE: 4846.77 © 2880 Technology Blvd. W. Bozeman, MT 59718 Phone: (406) 587-0721 Fax: (406) 922-6702 SHEET NUMBER PROJECT NUMBER DRAWING NUMBER DRAWN BY: CHK'D. BY: APPR. BY: DATE: Q.A. REVIEW DATE: BY: COPYRIGHT MORRISON-MAIERLE, INC.,2022 VERIFY SCALE! THESE PRINTS MAY BE REDUCED. LINE BELOW MEASURES ONE INCH ON ORIGINAL DRAWING. MODIFY SCALE ACCORDINGLY! REVISIONS DATEDESCRIPTIONNO.BY N:\3638\009\ACAD\Site Plans\Building-A\Everhome\Sheets\3638.009 C600 Overall Grading Plan.dwg Plotted by celine saucier on Feb/8/2022 engineerssurveyorsplannersscientistsengineerssurveyorsplannersscientists 3638.009 8 C601 BOZEMAN MONTANA CMS JAU JAU 2/2022 EVERHOME HOTEL GRADING PLAN SITE "A" BOZEMAN GATEWAY PUD 57.71 LF 24" CMP CULVERT EXTENSION @ 0.68% SLOPE INV IN: 4843.45 INV OUT: 4843.06 68.6" CMP CULVERT EXTENSION @ 0% SLOPE INV IN: 4842.93 INV OUT: 4842.93 CI #4 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 48.22 12" INV OUT (N) = 45.62 NOTES BY SYMBOL: 1 32.4LF OF 15" HDPE STORM PIPE @ 1% SLOPE .1 CI #5 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 48.20 12" INV IN (S) = 45.30 12" INV OUT (NE) = 45.30 2 .2 CI #6 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 42.87 12" INV IN (W) = 38.17 12" INV IN (N) = 38.17 12" INV IN (E) = 38.17 12" INV OUT (SE) = 38.17 3 .3 40LF OF 12" PVC STORM PIPE STUB @ 1% SLOPE 4. CI #7 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 43.00 12" INV IN (W) = 38.44 12" INV OUT (E) = 38.44 4 5. CI #8 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 42.61 12" INV IN (N) = 39.02 12" INV OUT (E) = 39.02 5 36.5LF OF 12" PVC STORM PIPE @ 1% SLOPE CI #9 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 42.06 12" INV IN (W) = 38.45 12" INV IN (S) = 38.45 15" INV OUT (E) = 38.45 6 CI #10 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 41.54 12" INV OUT (S) = 39.39 7 7. CI #11 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 41.65 12" INV OUT (E) = 38.54 8 9. CI #12 NEW 48"Ø COMBINATION STORM DRAIN MANHOLE AND INLET TBC = 41.50 15" INV IN (SW) = 37.31 15" INV OUT (NW) = 37.31 9 64LF OF 15" PVC STORM PIPE @ 1.15% SLOPE FUTURE SITE 72.7LF OF 15" PVC STORM PIPE @ 1.15% SLOPE 8. 36.5LF OF 12" PVC STORM PIPE @ 1% SLOPE 1/4" BELOW TOP OF NEW PAVEMENT SURFACE 3'-0" (MIN) HEAVY DUTY MONUMENT BOX, SIMILAR TO CAIRD ENG. NO. 50608-1 PAVING & GRAVEL AS REQUIRED SEAL JOINT WITH RAM-NEK 8" x 3' ROUND CONCRETE SLAB SLIP HUB TO THREADED ADAPTER THREADED PLUGFROST EXPANSION SLEEVE CLEANOUT PIPE - 4" Ø PVC 45° BEND NON-SHRINK BACKFILL END OF TRENCH VERIFY PIPE SIZE PER PLAN DIMENSIONS END OF LINE CLEANOUT (IF REQUIRED) USE PLUG AS REQUIRED USINGVARIABLE LENGTH SECTIONS36" MANHOLE STEPS AT 16" ON CENTER 24" OPENING FLAT SLAB COVER CUTOUTS ASREQUIRED PRECAST OR POURED-IN-PLACE BASE. POURED-IN-PLACE BASE, MINIMUM CONCRETE THICKNESS BELOW PIPE IS EIGHT INCHES (8"). PRECAST BASE, MINIMUM THICKNESS TO BE SIX INCHES (6"). POURED-IN-PLACE BASE TO EXTEND BEYOND OUTER EDGE OF MANHOLE WALL. NOTES: 1.ALL JOINTS BETWEEN MANHOLE SECTIONS, ADJUSTING RINGS, MANHOLE RING & TOP SECTION, AND AROUND PIPE INTO MANHOLE SHALL BEWATERTIGHT. JOINTING MATERIAL SHALL BE "RAM-NEK" OR APPROVED EQUAL FOR ALL JOINTS EXCEPT BETWEEN PIPE AND MANHOLE WALL. 2.ADJUSTING RINGS AND CASTING SHALL BE CENTERED ON MANHOLE. 3.REMOVE SHIMS AND GROUT ANY GAPS BETWEEN THE CASTING, ADJUSTING RINGS, AND BARREL. REMOVE EXCESS GROUT.4.GROUT ALL LIFTING HOLES IN BARREL. 5.ALL LATERAL PIPES SHALL BE FINISHED FLUSH WITH INNER BARREL WALL. MATCH TOP OF CURB ELEVATION EJIW 7030 SERIES CURB INLET FRAME, GRATE, & CURB HOOD 18" MINIMUM SLOPE SHELF AT 1" PER FOOT RADIUS OFMANHOLE SECTION A-A FRAME AND COVER TO BE EITHER D&L A-1172 RING & A-1178 COVER,EJIW 3771 / 3772 SERIES, OR APPROVED EQUAL. (COVERS SHALL BE STAMPED WITH THE WORDS "SANITARY SEWER" OR "STORMSEWER" AS APPROPRIATE AND HAVE TWO 1" PICK HOLES) MANHOLE RING AND COVER SHALL BE ADJUSTED TO GRADE OF PAVEMENT SURFACE AS REQUIRED USINGVARIABLE LENGTH SECTIONS AS REQUIRED MANHOLE STEPS AT 16" ON CENTER 24" OR 27" OPENING ADJUSTABLE RINGS 4" MIN TO 12" MAX FLAT SLAB COVER CUTOUTS AS REQUIRED A A CHANNEL = 1/2 DIAMETER OF PIPE SHELF: SLOPE AT 1" PER FOOT TOWARDS CHANNEL SEE CHANNEL DETAIL PRECAST OR POURED-IN-PLACE BASE.POURED-IN-PLACE BASE, MINIMUM CONCRETE THICKNESS BELOW PIPE IS EIGHT INCHES (8"). PRECAST BASE, MINIMUM THICKNESS TO BE SIX INCHES (6"). POURED-IN-PLACE BASE TO EXTEND BEYOND OUTER EDGE OF MANHOLE WALL. NOTES: 1.ALL JOINTS BETWEEN MANHOLE SECTIONS, ADJUSTING RINGS, MANHOLERING & TOP SECTION, AND AROUND PIPE INTO MANHOLE SHALL BEWATERTIGHT. JOINTING MATERIAL SHALL BE "RAM-NEK" OR APPROVEDEQUAL FOR ALL JOINTS EXCEPT BETWEEN PIPE AND MANHOLE WALL.2.ADJUSTING RINGS AND CASTING SHALL BE CENTERED ON MANHOLE.3.REMOVE SHIMS AND GROUT ANY GAPS BETWEEN THE CASTING, ADJUSTINGRINGS, AND BARREL. REMOVE EXCESS GROUT.4.GROUT ALL LIFTING HOLES IN BARREL. 5.ALL LATERAL PIPES SHALL BE FINISHED FLUSH WITH INNER BARREL WALL. NOTE: STORM DRAIN MANHOLES SHALL NOT HAVEFORMED CHANNELS ANDTHE LOWEST PIPE INVERTSHALL BE NINE INCHES (9")HIGHER THAN THE BOTTOMOF THE MANHOLE. SD MH #3 - SECTION SCALE: N.T.S. SD MH #5 - SECTION SCALE: N.T.S. . . . . COMBINATION MANHOLE AND CURB INLET SCALE: NTS 4 © 2880 Technology Blvd. W. Bozeman, MT 59718 Phone: (406) 587-0721 Fax: (406) 922-6702 SHEET NUMBER PROJECT NUMBER DRAWING NUMBER DRAWN BY: CHK'D. BY: APPR. BY: DATE: Q.A. REVIEW DATE: BY: COPYRIGHT MORRISON-MAIERLE, INC.,2022 VERIFY SCALE! THESE PRINTS MAY BE REDUCED. LINE BELOW MEASURES ONE INCH ON ORIGINAL DRAWING. MODIFY SCALE ACCORDINGLY! REVISIONS DATEDESCRIPTIONNO.BY N:\3638\009\ACAD\Site Plans\Building-A\Everhome\Sheets\3638.009 C700 Site Details.dwg Plotted by celine saucier on Feb/8/2022 engineerssurveyorsplannersscientistsengineerssurveyorsplannersscientists 3638.009 10 C701 BOZEMAN MONTANA CMS JAU JAU 2/2022 EVERHOME HOTEL SITE DETAILS SITE "A" BOZEMAN GATEWAY PUD STANDARD STRAIGHT MANHOLE SCALE: NTS 5 APPENDIX A Previously Approved Drainage Submittals Page 1 of 3 Storm Drainage Calculations Bozeman Gateway - Building F Site Plan June 19, 2014 1 Introduction This summary report provides hydrologic and hydraulic calculations for sizing of detention storage facilities and other storm drainage structures for development of the Building F site, including future development of the entire Bozeman Gateway Block 5 bordered by Fowler, Garfield, Technology Boulevard and Harmon Stream Boulevard. The storm drainage collection system will be phased in as development occurs, but all Block 5 detention and treatment facilities will be constructed in this first phase, along with Building F. The site is a retail development located south of the developed Bozeman Gateway, Block 2. Pre-development topography is gradual, about 2 to 3 percent slope from south to north. Existing ground cover is undeveloped, previously agricultural fields. 2 Approach Drainage calculations from the Bozeman Gateway Phase 1 application were used as a reference. Preliminary design has been completed for all of Block 5, and is the basis for post-development runoff calculations. Figure 2 shows the currently proposed site development. Conservatively high values for impervious area are assumed for these areas of future development. Pre-development sub-basin H1.1 (see Figure 1) corresponds to developed sub-basins D1.1 through D1.3, and pre-development sub-basin H2.2 corresponds to developed sub-basins D2.2A and D2.2B. Pre- and post-development drainage maps are attached as Figures 1 and 2. The 10-year peak runoff rates for D1.1 and D1.2 were calculated in the Bozeman Gateway Phase 1 application to be 1.05 and 0.84 cfs respectively; their total (1.89 cfs) was used in the detention calculations for sub-basin D1.3. Sub-basin D1.3 will drain to a proposed underground detention facility; this facility will discharge into the existing storm drain under Technology Boulevard and the Rosauers parking lot. Direct runoff from sub-basin D2.2A (stream “open space” area, primarily undeveloped), combined with discharge from a second underground detention facility proposed for sub-basin D2.2B, will drain to Harmon Stream. In each case, the post-development 10-year peak runoff rate will be limited to the pre-development rate. All storm drain pipes were sized to convey the 25-year peak runoff. 3 Detention Sub-basins D1.3 and D2.2B will drain to two separate “StormTech” pre-fabricated underground storage and infiltration systems. Each will include an inlet manhole that doubles as access for cleaning the isolator (sediment accumulation) row of the system. In a 10-year or smaller storm runoff event, all runoff will be routed through the StormTech system, and will discharge through a control structure. Detention volume and pipe sizing calculations are attached. Design details will be provided on the construction drawings. Page 2 of 3 Sub-Basin D1.3 Detention: Based on the maximum detention release rate of 0.34 cfs, the required minimum detention volume was calculated to be 1,735 cubic feet. The detention outlet control structure will consist of a vertical tee with a 2¾” diameter (or a 25/8” x 2¼” rectangular) orifice on the bottom, and an 18” diameter vertical riser to pass runoff exceeding the 10-year storage maximum water surface elevation into the piped storm drain system. The top of the overflow riser will be set at elevation 48.00, equal to the 10-year maximum water surface elevation of the detention storage facility. The head required to pass the 25-year peak runoff of 4.36 cfs over the riser is 0.47 feet, which is low enough to ensure piped conveyance of the 25-year peak runoff. A 12” PVC discharge pipe is required to convey the 25-year peak runoff to the existing Block 2 collection system. Sub-Basin D2.2B Detention: Based on the maximum detention release rate of 0.39 cfs, the required minimum detention volume was calculated to be 7,367 cubic feet. The detention outlet control structure will consist of a vertical tee with a 215/16” diameter (or a 211/16” x 2½” rectangular) orifice on the bottom, and a 24” diameter vertical riser to pass runoff exceeding the 10-year storage maximum water surface elevation into the piped storm drain system. The top of the overflow riser will be set at elevation 48.70, equal to the 10-year maximum water surface elevation of the detention storage facility. The head required to pass the 25-year peak runoff of 10.57 cfs over the riser is 0.70 feet, which is low enough to ensure piped conveyance of the 25-year peak runoff. An 18” PVC discharge pipe is required to convey the 25-year peak runoff to Harmon Stream. N:\3638\009\Design Docs\Drainage\Building S\Drainage Report.doc Page 3 of 3 Record Id: H1.1 Pervious TC Calc Type Description Length Slope Coeff Misc TT Sheet Cultivated Soil w/ residue cover (s<=20%).: 0.06 150.00 ft 1.70% 0.0600 1.20 in 11.35 min Shallow Fallow or minimum tillage cultivation (n=0.04) 460.00 ft 1.60% 0.0400 7.55 min Channel (interm) Grassed (n=0.030) 160.00 ft 2.50% 0.0300 0.99 min Channel (interm) Grassed (n=0.030) 300.00 ft 0.30% 0.0300 5.37 min Pervious TC 25.27 min Record Id: H2.2 TC Calc Type Description Length Slope Coeff Misc TT Sheet Short prairie grass and lawns.: 0.15 60.00 ft 1.70% 0.1500 1.20 in 11.35 min Shallow Short grass, pasture and lawns (n=0.030) 230.00 ft 1.30% 0.0300 3.14 min Channel (interm) Grassed (n=0.030) 360.00 ft 1.70% 0.0300 2.71 min Channel (interm) Grassed (n=0.030) 440.00 ft 0.60% 0.0300 5.57 min Pervious TC 22.77 min Record Id: D2.2A TC Calc Type Description Length Slope Coeff Misc TT Sheet Short prairie grass and lawns.: 0.15 60.00 ft 1.80% 0.1500 1.20 in 11.09 min Shallow Short grass, pasture and lawns (n=0.030) 130.00 ft 1.90% 0.0300 1.47 min Channel (interm) Grassed (n=0.030) 680.00 ft 1.70% 0.0300 5.12 min Pervious TC 17.68 min Record Id: H2.2B TC Calc Type Description Length Slope Coeff Misc TT Sheet Short prairie grass and lawns.: 0.15 29.00 ft 8.70% 0.1500 1.20 in 3.30 min Shallow asphalt 100.00 ft 2.60% 0.0130 0.42 min Channel (interm) pipe 520.00 ft 0.90% 0.0110 1.97 min Pervious TC 5.69 min Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.011 Channel Slope 1.20 % Diameter 12 in Discharge 4.21 ft³/s Results Normal Depth 0.75 ft Flow Area 0.63 ft² Wetted Perimeter 2.10 ft Hydraulic Radius 0.30 ft Top Width 0.86 ft Critical Depth 0.87 ft Percent Full 75.1 % Critical Slope 0.00919 ft/ft Velocity 6.66 ft/s Velocity Head 0.69 ft Specific Energy 1.44 ft Froude Number 1.37 Maximum Discharge 4.96 ft³/s Discharge Full 4.61 ft³/s Slope Full 0.01000 ft/ft Flow Type SuperCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % Normal Depth Over Rise 75.09 % Downstream Velocity Infinity ft/s D1.3, 25-yr discharge 6/19/2014 3:38:07 PM Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 2of1Page Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.011 Channel Slope 0.80 % Diameter 18 in Discharge 10.57 ft³/s Results Normal Depth 1.17 ft Flow Area 1.48 ft² Wetted Perimeter 3.25 ft Hydraulic Radius 0.46 ft Top Width 1.24 ft Critical Depth 1.25 ft Percent Full 78.0 % Critical Slope 0.00705 ft/ft Velocity 7.15 ft/s Velocity Head 0.79 ft Specific Energy 1.96 ft Froude Number 1.16 Maximum Discharge 11.94 ft³/s Discharge Full 11.10 ft³/s Slope Full 0.00725 ft/ft Flow Type SuperCritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % Normal Depth Over Rise 77.96 % Downstream Velocity Infinity ft/s D2.2B, 25-yr discharge 6/19/2014 3:40:58 PM Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 2of1Page PRE-DEVELOPMENT DRAINAGE MAPBOZEMAN GATEWAYBUILDING "F" SITE PLAN / BLOCK 5 BOZEMAN GATEWAYFIGURE NUMBERˆPROJECT NO.DRAWN BY:CHK'D. BY:APPR. BY:DATE:COPYRIGHT MORRISON-MAIERLE, INC.,20142880 Technology Blvd. W.Bozeman MT 59771Phone: (406) 587-0721Fax: (406) 922-6703N:\3638\009\ACAD\Exhibits\ROSAUERS STORM DRAIN DRAINAGE BASINS.dwg Plotted by cody farley on Jun/19/20143638.009FIG. 1BOZEMANMONTANACJFMGHMGH06/2014LEGEND POST-DEVELOPMENT DRAINAGE MAPFIGURE NUMBERˆPROJECT NO.DRAWN BY:CHK'D. BY:APPR. BY:DATE:COPYRIGHT MORRISON-MAIERLE, INC.,20142880 Technology Blvd. W.Bozeman MT 59771Phone: (406) 587-0721Fax: (406) 922-6703N:\3638\009\ACAD\Exhibits\ROSAUERS STORM DRAIN DRAINAGE BASINS.dwg Plotted by cody farley on Jun/19/20143638.009FIG. 2BOZEMANMONTANACJFMGHMGH06/2014BOZEMAN GATEWAY BUILDING "F" SITE PLAN / BLOCK 5 BOZEMAN GATEWAYLEGENDSD APPENDIX B Stormwater Calculations Site A - Everhome Hotel Peak Runoff Calculations MODIFIED RATIONAL METHOD i = A * (Tc/60) B Qp = C i A Qp = peak runoff, cfs Design Coefficients C = runoff coefficient Storm A B i = A(Tc/60)B (Bozeman IDF curve)2-yr 0.36 -0.60 Tc = time of concentration, minutes 5-yr 0.52 -0.64 A = Area, acres 10-yr 0.64 -0.65 25-yr 0.78 -0.64 50-yr 0.92 -0.66 Retention Volume =7,200*(C)*(i)*(A),where i =0.41 in./hr 100-yr 1.01 -0.67 (Bozeman Design Standards, March 2004) Retention Sub-Basin Name Area C Tc Q2 Q5 Q10 Q25 Q50 Q100 Volume (ft.3) H1 0.94 0.20 50.00 0.08 0.11 0.14 0.17 0.20 0.22 H2 4.48 0.20 43.00 0.39 0.58 0.71 0.87 1.03 1.13 D1 (direct)0.45 0.24 50.00 0.04 0.06 0.08 0.10 0.11 0.13 D2.1 0.83 0.85 5.00 1.14 1.82 2.29 2.72 3.38 3.80 2,101 D2.2 2.14 0.82 5.00 2.82 4.49 5.67 6.74 8.36 9.41 5,202 D2.3a 0.57 0.20 11.50 0.11 0.17 0.21 0.25 0.31 0.35 335 D2.3b 0.73 0.26 16.60 0.15 0.23 0.28 0.34 0.41 0.46 563 D2.3a+D2.3b (direct)1.30 0.23 26.90 0.18 0.26 0.33 0.40 0.48 0.53 898 Existing Pond Fowler 1.02 0.8 5 1.30467 2.08 2.63 3.12 3.87 4.36 2,409 Site A - Everhome Hotel Sub-Basin 2.1 Detention (10-yr storm) MODIFIED RATIONAL METHOD Qp = C i A POST-DEVELOPMENT PRE-DEVEL. 0.83 AC Qp (Basin H1) = 0.71 cfs Direct Runoff (Basin D2.3) = -0.33 cfs 0.85 0.38 5.0 MIN D2.1 release rate = 0.08 cfs 3.22 IN/HR TIME STEP 2.29 CFS DURATION = 5.0 min. Max. Volume, Max. Volume,Required Detention Triangle Rel. (cu. ft.) Constant Rel. (cu. ft.)Volume (cu. ft.) 2232.66 1529.89 1,881 Triangle Release Constant Release DURATION INTENSITY Qp POND VOLUME POND VOLUME (MIN) (IN/HR) (CFS) (CF) (CF) 4.75 3.33 2.37 652 629 9.75 2.09 1.48 833 799 14.75 1.59 1.13 956 911 19.75 1.32 0.94 1,052 995 ORIFICE CALCULATIONS 24.75 1.14 0.81 1,132 1,063 MATCHING Qp = 0.08 cfs 29.75 1.01 0.72 1,200 1,119 Max. Depth = 3.00 ft 34.75 0.91 0.65 1,259 1,167 39.75 0.84 0.60 1,313 1,208 44.75 0.77 0.55 1,361 1,245 49.75 0.72 0.51 1,405 1,277 CIRCULAR ORIFICE: 54.75 0.68 0.48 1,445 1,305 DIAMETER = 1.2500 inches 59.75 0.64 0.46 1,482 1,331 Area = 0.01 ft 2 64.75 0.61 0.43 1,517 1,354 ORIFICE FLOW = 0.07 CFS 69.75 0.58 0.41 1,549 1,375 74.75 0.55 0.39 1,580 1,393 79.75 0.53 0.38 1,608 1,410 RECTANGULAR ORIFICE: 84.75 0.51 0.36 1,635 1,425 LENGTH = 1.188 inches 89.75 0.49 0.35 1,661 1,439 WIDTH = 1.188 inches 94.75 0.48 0.34 1,685 1,451 Area = 0.01 ft 2 99.75 0.46 0.33 1,708 1,462 ORIFICE FLOW = 0.08 CFS 104.75 0.45 0.32 1,730 1,472 109.75 0.43 0.31 1,751 1,481 114.75 0.42 0.30 1,770 1,489 119.75 0.41 0.29 1,789 1,497 124.75 0.40 0.28 1,808 1,503 WEIR CALCULATIONS (not used) 129.75 0.39 0.28 1,825 1,508 Coefficient = 3.33 inches 134.75 0.38 0.27 1,842 1,513 Width = 0.1875 inches 139.75 0.37 0.26 1,857 1,517 WEIR FLOW = 0.27 CFS 144.75 0.36 0.26 1,873 1,521 149.75 0.35 0.25 1,887 1,524 154.75 0.35 0.25 1,902 1,526 159.75 0.34 0.24 1,915 1,528 164.75 0.33 0.24 1,928 1,529 169.75 0.33 0.23 1,941 1,530 174.75 0.32 0.23 1,953 1,530 179.75 0.31 0.22 1,965 1,530 184.75 0.31 0.22 1,976 1,529 189.75 0.30 0.22 1,987 1,528 194.75 0.30 0.21 1,997 1,527 199.75 0.29 0.21 2,007 1,525 204.75 0.29 0.21 2,017 1,523 209.75 0.28 0.20 2,026 1,520 POST-DEV Qp = POND VOLUME CALCULATIONS: BASIN AREA POST = POST-DEV Tc = POST-DEV C = STORM INTENSITY = User Inputs Chamber Model: SC-740 Outlet Control Structure: Yes Project Name: Everhome Engineer: Celine Saucier Project Location: Montana Measurement Type: Imperial Required Storage Volume: cubic ft. Stone Porosity: 40% Stone Foundation Depth: 6 in. Stone Above Chambers: 6 in. Average Cover Over Chambers: 18 in. Design Constraint Dimensions:(16.90 ft. x 72 ft.) Results System Volume and Bed Size Installed Storage Volume: 2382.07 cubic ft. Storage Volume Per Chamber: 45.90 cubic ft. Number Of Chambers Required: 27 Number Of End Caps Required: 6 Chamber Rows: 3 Maximum Length:71.58 ft. Maximum Width: 16.35 ft. Approx. Bed Size Required: 1170.35 square ft. System Components Amount Of Stone Required: 105.81 cubic yards Volume Of Excavation (Not Including Fill): 151.71 cubic yards Non-woven Geotextile Required (ex- cluding Isolator Row): 394.16 square yards Non-woven Geotextile Required (Iso- lator Row): 70.03 square yards Total Non-woven Geotextile Required:464.19 square yards Woven Geotextile Required (excluding Isolator Row): 15.83 square yards Woven Geotextile Required (Isolator Row): 43.77 square yards Total Woven Geotextile Required:59.60 square yards Site A - Everhome Hotel Sub-Basin D2.2 Detention (10-yr storm) MODIFIED RATIONAL METHOD Qp = C i A POST-DEVELOPMENT PRE-DEVEL. 2.14 AC Qp (Basin H2) = 0.71 cfs Direct Runoff (Basin D2.3) = -0.33 cfs 0.82 Release Rate (Basin 2.1) = -0.08 cfs 5.0 MIN D2.2 release rate = 0.30 cfs 3.22 IN/HR TIME STEP 5.67 CFS DURATION = 5.0 min. Max. Volume, Max. Volume,Required Detention Triangle Rel. (cu. ft.) Constant Rel. (cu. ft.)Volume (cu. ft.) 4359.04 2973.36 3,666 Triangle Release Constant Release DURATION INTENSITY Qp POND VOLUME POND VOLUME (MIN) (IN/HR) (CFS) (CF) (CF) 4.75 3.33 5.86 1,582 1,498 9.75 2.09 3.67 2,015 1,887 14.75 1.59 2.81 2,304 2,133 19.75 1.32 2.32 2,525 2,311 ORIFICE CALCULATIONS 24.75 1.14 2.01 2,706 2,448 MATCHING Qp = 0.30 cfs 29.75 1.01 1.78 2,858 2,556 Max. Depth = 3.00 ft 34.75 0.91 1.61 2,990 2,644 39.75 0.84 1.47 3,106 2,715 44.75 0.77 1.36 3,209 2,774 49.75 0.72 1.27 3,302 2,823 CIRCULAR ORIFICE: 54.75 0.68 1.20 3,385 2,862 DIAMETER = 1.750 inches 59.75 0.64 1.13 3,462 2,894 Area = 0.02 ft2 64.75 0.61 1.07 3,532 2,920 ORIFICE FLOW = 0.14 CFS 69.75 0.58 1.02 3,596 2,940 74.75 0.55 0.98 3,655 2,954 79.75 0.53 0.94 3,710 2,965 RECTANGULAR ORIFICE: 84.75 0.51 0.90 3,761 2,971 LENGTH = 1.625 inches 89.75 0.49 0.87 3,808 2,973 WIDTH = 1.625 inches 94.75 0.48 0.84 3,852 2,973 Area = 0.02 ft2 99.75 0.46 0.81 3,892 2,969 ORIFICE FLOW = 0.15 CFS 104.75 0.45 0.79 3,930 2,962 109.75 0.43 0.76 3,966 2,953 114.75 0.42 0.74 3,999 2,941 WEIR CALCULATIONS (not used) 119.75 0.41 0.72 4,030 2,928 Coefficient = 3.33 inches 124.75 0.40 0.70 4,059 2,912 Width = 0.5000 inches 129.75 0.39 0.68 4,086 2,894 WEIR FLOW = 0.72 CFS 134.75 0.38 0.67 4,111 2,874 139.75 0.37 0.65 4,134 2,853 144.75 0.36 0.64 4,156 2,830 149.75 0.35 0.62 4,176 2,806 154.75 0.35 0.61 4,195 2,780 159.75 0.34 0.60 4,213 2,753 164.75 0.33 0.58 4,229 2,724 169.75 0.33 0.57 4,244 2,695 174.75 0.32 0.56 4,258 2,664 179.75 0.31 0.55 4,271 2,632 184.75 0.31 0.54 4,283 2,599 189.75 0.30 0.53 4,294 2,565 194.75 0.30 0.52 4,303 2,530 199.75 0.29 0.52 4,312 2,494 204.75 0.29 0.51 4,320 2,457 POND VOLUME CALCULATIONS: BASIN AREA POST = POST-DEV C = POST-DEV Tc = STORM INTENSITY = POST-DEV Qp = User Inputs Chamber Model: SC-740 Outlet Control Structure: Yes Project Name: Site A Engineer: Celine Saucier Project Location: Montana Measurement Type: Imperial Required Storage Volume: cubic ft. Stone Porosity: 40% Stone Foundation Depth: 6 in. Stone Above Chambers: 6 in. Average Cover Over Chambers: 18 in. Design Constraint Dimensions:(20 ft. x 125 ft.) Results System Volume and Bed Size Installed Storage Volume: 4100.72 cubic ft. Storage Volume Per Chamber: 45.90 cubic ft. Number Of Chambers Required: 48 Number Of End Caps Required: 6 Chamber Rows: 3 Maximum Length:121.40 ft. Maximum Width: 16.35 ft. Approx. Bed Size Required: 1984.86 square ft. System Components Amount Of Stone Required: 175.70 cubic yards Volume Of Excavation (Not Including Fill): 257.30 cubic yards Non-woven Geotextile Required (ex- cluding Isolator Row): 657.86 square yards Non-woven Geotextile Required (Iso- lator Row): 123.16 square yards Total Non-woven Geotextile Required:781.02 square yards Woven Geotextile Required (excluding Isolator Row): 15.83 square yards Woven Geotextile Required (Isolator Row): 76.98 square yards Total Woven Geotextile Required:92.81 square yards APPENDIX C Conveyance Calculations Site A - Everhome Hotel Conveyance Calculations (25-yr storm) MODIFIED RATIONAL METHOD Qp = C i A Qp = 25-yr peak runoff, cfs C = runoff coefficient i = 0.78(Tc/60)-0.64 (Bozeman IDF curve) Tc = time of concentration, minutes A = Area, acres Basin Name Area1 C Tc Qpipe-25 yr 2 Pipe Dia.3 Pipe Slope Capacity Pipe Flow D2.1 0.83 0.85 5.00 2.72 12"1.0% 4.15 D2.2 2.14 0.82 5.00 6.74 15"1.15% 8.07 Basin Name Area1 C Tc Qpipe-25 yr 2 Pipe Dia.3 Pipe Slope Culvert Flow Famers Canal Flow 21.41 #1 D2.3a 0.57 0.20 11.50 0.25 D2.3a + Farmers Canal Flow 21.66 30"1.50% #2 D2.3b 0.73 0.26 16.60 0.34 D2.3a+D2.3b + Farmers Canal Flow 22.00 30"2.6% #3 D2.3a+D2.3b + Farmers Canal Flow 22.00 42"1.40% Offsite Flow Rosauers and Building F 25.83 Existing Pond 3.12 Existing Huffine Culvert 62.07 42"0.74% FOOTNOTES: 1. Contributing drainage area (conservatively high in some cases) 2.Qpipe is the total 25-year peak runoff (direct surface runoff plus flows from upstream pipes) to the pipe draining the indicated structure/flow entry point. Channel Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Tuesday, Jun 23 2020 Det 2.1 / D2.4 Circular Diameter (ft) = 1.00 Invert Elev (ft) = 100.00 Slope (%) = 1.00 N-Value = 0.012 Calculations Compute by: Q vs Depth No. Increments = 20 Highlighted Depth (ft) = 0.95 Q (cfs) = 4.145 Area (sqft) = 0.77 Velocity (ft/s) = 5.37 Wetted Perim (ft) = 2.70 Crit Depth, Yc (ft) = 0.86 Top Width (ft) = 0.43 EGL (ft) = 1.40 0 1 2 3 Elev (ft)Depth (ft)Section 99.50 -0.50 100.00 0.00 100.50 0.50 101.00 1.00 101.50 1.50 102.00 2.00 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Tuesday, Jun 23 2020 Det 2.2 + D2.4 Circular Diameter (ft) = 1.25 Invert Elev (ft) = 100.00 Slope (%) = 1.15 N-Value = 0.012 Calculations Compute by: Q vs Depth No. Increments = 50 Highlighted Depth (ft) = 1.17 Q (cfs) = 8.070 Area (sqft) = 1.20 Velocity (ft/s) = 6.74 Wetted Perim (ft) = 3.31 Crit Depth, Yc (ft) = 1.12 Top Width (ft) = 0.59 EGL (ft) = 1.88 0 1 2 3 Elev (ft)Section 99.50 100.00 100.50 101.00 101.50 102.00 Reach (ft) Culvert Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Aug 10 2021 Culvert #1 - 25 year Storm Invert Elev Dn (ft) = 4840.16 Pipe Length (ft) = 65.30 Slope (%) = 1.50 Invert Elev Up (ft) = 4841.14 Rise (in) = 30.0 Shape = Circular Span (in) = 30.0 No. Barrels = 1 n-Value = 0.015 Culvert Type = Circular Concrete Culvert Entrance = Square edge w/headwall (C) Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 Embankment Top Elevation (ft) = 4846.19 Top Width (ft) = 35.00 Crest Width (ft) = 100.00 Calculations Qmin (cfs) = 21.80 Qmax (cfs) = 21.80 Tailwater Elev (ft) = (dc+D)/2 Highlighted Qtotal (cfs) = 21.80 Qpipe (cfs) = 21.80 Qovertop (cfs) = 0.00 Veloc Dn (ft/s) = 5.08 Veloc Up (ft/s) = 6.64 HGL Dn (ft) = 4842.20 HGL Up (ft) = 4842.73 Hw Elev (ft) = 4843.59 Hw/D (ft) = 0.98 Flow Regime = Inlet Control Culvert Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Aug 10 2021 Culvert #2 - 25 year Storm Invert Elev Dn (ft) = 4837.30 Pipe Length (ft) = 48.88 Slope (%) = 2.60 Invert Elev Up (ft) = 4838.57 Rise (in) = 30.0 Shape = Circular Span (in) = 30.0 No. Barrels = 1 n-Value = 0.015 Culvert Type = Circular Concrete Culvert Entrance = Square edge w/headwall (C) Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 Embankment Top Elevation (ft) = 4842.66 Top Width (ft) = 10.00 Crest Width (ft) = 100.00 Calculations Qmin (cfs) = 22.23 Qmax (cfs) = 22.23 Tailwater Elev (ft) = (dc+D)/2 Highlighted Qtotal (cfs) = 22.23 Qpipe (cfs) = 22.23 Qovertop (cfs) = 0.00 Veloc Dn (ft/s) = 5.16 Veloc Up (ft/s) = 6.69 HGL Dn (ft) = 4839.35 HGL Up (ft) = 4840.17 Hw Elev (ft) = 4841.04 Hw/D (ft) = 0.99 Flow Regime = Inlet Control Culvert Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Aug 10 2021 Culvert #3 - 25 year Storm Invert Elev Dn (ft) = 4834.13 Pipe Length (ft) = 49.70 Slope (%) = 1.41 Invert Elev Up (ft) = 4834.83 Rise (in) = 42.0 Shape = Circular Span (in) = 42.0 No. Barrels = 1 n-Value = 0.015 Culvert Type = Circular Concrete Culvert Entrance = Square edge w/headwall (C) Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 Embankment Top Elevation (ft) = 4838.90 Top Width (ft) = 10.00 Crest Width (ft) = 100.00 Calculations Qmin (cfs) = 22.23 Qmax (cfs) = 22.23 Tailwater Elev (ft) = (dc+D)/2 Highlighted Qtotal (cfs) = 22.23 Qpipe (cfs) = 22.23 Qovertop (cfs) = 0.00 Veloc Dn (ft/s) = 3.06 Veloc Up (ft/s) = 5.93 HGL Dn (ft) = 4836.60 HGL Up (ft) = 4836.28 Hw Elev (ft) = 4836.85 Hw/D (ft) = 0.58 Flow Regime = Inlet Control Culvert Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Monday, Jun 15 2020 Existing Huffine Culvert - 10yr Storm Invert Elev Dn (ft) = 4832.01 Pipe Length (ft) = 131.76 Slope (%) = 0.74 Invert Elev Up (ft) = 4832.99 Rise (in) = 42.0 Shape = Circular Span (in) = 42.0 No. Barrels = 1 n-Value = 0.012 Culvert Type = Circular Concrete Culvert Entrance = Square edge w/headwall (C) Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 Embankment Top Elevation (ft) = 4838.48 Top Width (ft) = 10.00 Crest Width (ft) = 100.00 Calculations Qmin (cfs) = 0.00 Qmax (cfs) = 42.69 Tailwater Elev (ft) = (dc+D)/2 Highlighted Qtotal (cfs) = 42.69 Qpipe (cfs) = 42.69 Qovertop (cfs) = 0.00 Veloc Dn (ft/s) = 5.23 Veloc Up (ft/s) = 7.36 HGL Dn (ft) = 4834.78 HGL Up (ft) = 4835.02 Hw Elev (ft) = 4836.05 Hw/D (ft) = 0.87 Flow Regime = Inlet Control Culvert Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Tuesday, Jun 23 2020 Existing Huffine Culvert - 25yr Storm Invert Elev Dn (ft) = 4832.01 Pipe Length (ft) = 131.76 Slope (%) = 0.74 Invert Elev Up (ft) = 4832.99 Rise (in) = 42.0 Shape = Circular Span (in) = 42.0 No. Barrels = 1 n-Value = 0.012 Culvert Type = Circular Concrete Culvert Entrance = Square edge w/headwall (C) Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5 Embankment Top Elevation (ft) = 4838.48 Top Width (ft) = 10.00 Crest Width (ft) = 100.00 Calculations Qmin (cfs) = 0.00 Qmax (cfs) = 62.07 Tailwater Elev (ft) = (dc+D)/2 Highlighted Qtotal (cfs) = 62.07 Qpipe (cfs) = 62.07 Qovertop (cfs) = 0.00 Veloc Dn (ft/s) = 7.10 Veloc Up (ft/s) = 8.56 HGL Dn (ft) = 4834.99 HGL Up (ft) = 4835.46 Hw Elev (ft) = 4836.99 Hw/D (ft) = 1.14 Flow Regime = Inlet Control