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HomeMy WebLinkAboutCC - Storm Drainage Calcs ESE C O N S U LTA N T S ESE Consultants, Inc. 3103 W. Sheryl Drive ENGINEERING • PLANNING • SURVEYING • ENVIRONMENTAL Meridian, Idaho 83642 Tri 208424-0020 STORMWATER MANAGEMENT REPORT FOR OAKS NORTH SUBDIVISION, PHASE 13 �S\ONAL FN .. BLOCK 26 N s Cj IEEE] f I a v G Fp FA P - 18043 25 tl -� — NA �O �6F j SSMH 13.03 / r Mark R . Za y — Professional Engineer Idaho License No . 18043 SSMH 13.02 SSMH 13.01 August 2023 34 I 0 I e I 13 31 LOCATECIN : CITY OF MERIDIAN ADA COUNTY, IDAHO TABLE OF CONTENTS SUBJECT SECTION Project Overview 1 Stormwater Management Design 2 Stormwater Equations 3 Primary Conveyance & Stormwater Facility Calculations 4 Swale Calculations 5 Intensity-Duration-Frequency Curve 6 Pipe Flow Calculations 7 Drainage Basin Map 8 SECTION 1 - Project Overview The Oaks North Subdivision No. 13 is a part of a multi-phase residential development located in the City of Meridian, Ada County, Idaho. The development is situated along the north side of West McMillan Road, between North Black Cat Road and North McDermott Road. The applicant proposes to develop eighteen (18) single family residential lots with this phase of the project on approximately 7.4 acres. The development includes the construction of homes and infrastructure to include roads, sidewalks, a stormwater management facility, utilities, and other improvements typical of residential construction. Existing Conditions The project site is currently bounded by single family residential developments to the south (Jump Creek Subdivision) to North (Westbridge Subdivision) and to the West (Oaks North Subdivision). The project site itself is comprised of existing irrigated farmland with a houise and ancillary buildings, and irrigation delivery ditches. The existing terrain is relatively flat with slopes generally less than one percent. The site slopes down gradient from east to west. Geotechnical Characteristics A Geotechnical Engineering Report was prepared by Materials Testing and Inspection (MTI) for the Oaks North Subdivision, dated July 20, 2018. The soils were generally described as having a hard pan layer at approximately 3-7 feet below the ground surface overlain by clay material. Gravel and sands were generally observed below the hard pan layer. An additional Geotechnical Report was prepared by Geotek in April of this year which provides 5 additional Test Pits with groundwater elevations. The highest groundwater elevation from this report was used in the underground Sand Filter design. Groundwater Groundwater monitoring of the project site was commenced by MTI in June 2018. A summary of the groundwater elevations observed on site to date have been recorded by MTI in the Groundwater Letter dated, November 20, 2019. The groundwater has been observed at depths between 3-ft and 10-ft below the ground surface. The additional testing completed by Geotek in April of this year resulted in a similar range of groundwater depths. Soil Infiltration MTI performed soil infiltration tests at four locations within the project site and presented their results in Addendum#2 to the Geotechnical Engineering Report,dated February 8,2019. Results of the soil infiltration rates ranged from a low of 0.24 in/hr to a high of more than 8 in/hr. An infiltration rate of 1 in/hr was utilized for design purposes. SECTION 2 - Stormwater Management Design Design Criteria The Stormwater Management Plan described herein has been designed according to the Ada County Highway District Policy Manual. The proposed Stormwater Management Design has been prepared to meet the following requirements and guidelines: ♦ The Rational Method (Q=CiA) has been utilized to calculate peak flows. Runoff coefficients were used per the ACHD Policy Manual. Rainfall intensities were determined using the ACHD adopted Intensity-Duration-Frequency Curve located in Section 5 of this report. Calculations for the requisite time of concentration (Tc) value are enclosed. The overland flow and gutter flow segments of the Tc were calculated based on the equations provided in the ACHD Policy Manual and enclosed within this report for reference. ♦ Pipe flow calculations are provided to demonstrate that the primary stormwater conveyance system is sized to adequately handle stormwater flows based on the 25-year storm event. ♦ The residential lot grading was designed to drain approximately the front half of the lot towards the street and is included in the stormwater basin calculations. Stormwater that falls within the back of the lots will be retained on site. Yard drains will be installed in the rear yards during home construction and final landscaping to facilitate infiltration of lot drainage. ♦ High groundwater observed through the site necessitated the use of a Vertical Sand Filter for the storage and infiltration of the 100-year storm event. An infiltration rate of 1 inch per hour has been used for the design of the vertical sand filter. A sand and grease trap is provided for pretreatment. ♦ Within Subdivision No. 13 there is one (1) proposed vertical sand filter noted as Basin A. Basin A is located within Block 21 Common Lot 41C. ♦ Stormwater runoff to the west of the W. River Oaks Drive highpoint was previously approved as part of Phase 11. SECTION 3 - Stormwater Equations Stormwater Conveyance ACHD Policy Manual 8011.2) Q - CIA where: Q - Discharge rate (cfs) - Coefficient of Runoff(dimensionless) i - Rainfall intensity (in1hr) for a duration equal to the time of concentration (Tc) over the contribuking area and for the design frequency. A - Site area (acres) Tc - Time of ooncentration Coefficient of Runoff(ACHD Policy Manual 8011.2.1) Estimated Ftunoff Coefficients for Various Surfaces Type ofSUrfaie Runoff Coefficients "C" Business Downtown areas 0.70.0.95 Urbannelghborhoods 0.50.0.70 Residential Single Family 0.35.0.50 Multifamily 0.60.0.75 Residential;rural) 0.25.0.40 Apartment Dwelling Areas. 0.70 Industrial and Commercial Light areas 0.80 Heavy areas 0.90 Parks,Cemeteries 0.10.0.25 Playgrounds 0.20-0.35 Railroad yaFd areas 0.20.0.40 UnlmpFaved areas 0.10.0.30 StFBBtS Asphalt 0.95 Gan{Fete 0.95 Brick 0.95 Rook 0.95 gravel 0.75 Fields:Sandy sail Soll Type Slope A B C Flat 0.2% 0.04 0.07 0.11 0.1S Average,2.6% 0.09 0.12 0.15 0.20 Steep' % 0.13 0.18 0.23 0.26 Ada pted from ASCE Design Storm Runoff Volume (ACHD Policy Manual 8011.3.2) V=CiA(3600) V: Design storm runoff volume required for storage C: Coefficient of Runoff is Rainfall Intensity per IDF Curve 1-hour 100-year storm event, i=0.96 1-hour 2-year storm event, i=0.26 A: Total catchment area(acres) Time of Concentration TC=TC-G+TC-s Tc : Total time of concentration LG Tc-c — 60 • VG Tc-G : Gutter time of concentration LG : Length of gutter flow VG : Gutter flow velocity VG=K„kSP0.5 K„ : Empirical coefficient(3.281) k : Intercept coefficient(0.619) SP : Slope (percent) 0.007(nL)0.8 Tc—S = (p2)0.5So.4 Tc-s : Overland time of concentration L : Length of overland(sheet) flow n : Manning's Roughness Coefficient(0.24) P2 : 2-year 24-hour rainfall(1.2 in.) S : Slope(ft/ft) Manning's Roughness Coefficient(ACHD Policy Manual 8011.5.3) Typical Range of Manning's Coefficient (n} for Channels and Pipes COnd4iil rrl t6ri01 f4l nrlirrg'S ' Closed Conduits concrete pipe 0-010-0.015 CRAP 0-011 -0.037 Plastic (smooth) 0-009-0.015 Plastic carru etedl 0.018-0.025 PavalvanUgunor seceions 0.012-0-016 Small Open Channels Concrete 0-011 -0.015 Rubble or riprap 0-020 - 0.035 Vegetation 0.020 - 0.150 Bate Soil 0.016- O.Q25 Rock Cut 0.025- 0.045 Natural onannals{minor streams. lop wpdth at flood stage <30 m(100 ft)I Fairiy regular section O.Q25- 0.050 Irr"ular were d'1 with pools 1 0.040- 0.150 -Lower values are usually For well-constructed and maintained(smoother)pEpes and charnels Table 3-2. Manning's Roughness Coefficient(n)for OVerland Sheet Flow.: Surface Description n Smooth asphalt O,011 Smooth concrete 0.012 Ordinary concrete lining 0.013 Good wood O.D14 Brick with cement mortar 0.014 Vitrified Clay O.D15 Cast iron O.D75 Corrugated metal pipe 0.024 Cement rubble surface 0.024 Fallow (no residue) 0-05 Cultivated soils Residue cover s 20% 0.06 Residua cover� 20% 0.17 Range(natural) O.13 Grass Short grass prairie 0.15 Dense grasses 0.24 Bermuda grass 0.41 woods' Light underbrush 0.40 Dense underbrush 0.80 When selecting n, consider cover to a heig ht of about 30 mm. This is only part of the plant cover that will obstruct sheet flow. SECTION 4 Primary Conveyance & Stormwater Facility Calculations BASIN CATCHMENT AREA A TIME OF CONCENTRATION Overland Flow Gutter Flow Sub-Catchment engt ope,s TC-s Liev ev 2 Length,LG Slope, p Gutter Tc-G Total Tc (ft) M (min.) (ft) (ft) (ft) M (ft/sec) (min.) (min.) A6 29.9 2.75 7.8 2537.4 2536.3 127 0.89 1.92 1.1 8.9 AS 57.8 2.75 13.2 2536.7 2536.3 73 0.63 1.61 0.8 14.0 A4 25.0 1.50 8.6 2537.7 2537.0 145 0.50 1.44 1.7 10.3 A3 75.0 1.50 20.8 2537.7 2537.0 145 0.51 1.45 1.7 22.4 A2 75.0 1.25 1 22.3 1 2539.7 2537.4 437 0.51 1.46 5.0 1 27.3 Al 75.0 1.25 22.3 2539.7 2537.4 446 0.50 1.44 5.2 27.5 CONVEYANCE Sub-Catchment C Area,A i2 i25 iioo 02 Q25 Q100 (acres) (in/hr) (in/hr) (in/hr) (cfs) (cfs) (cfs) A6 0.50 0.24 0.71 1.91 2.67 0.09 0.23 0.32 A5 0.50 0.23 0.61 1.62 2.26 0.07 0.19 0.26 A4 0.50 0.29 0.68 1.83 2.56 0.10 0.27 0.37 A3 0.50 0.47 0.46 1.22 1.70 0.11 0.29 0.40 A2 0.50 1.01 0.42 1.11 1.55 0.21 0.56 0.78 Al 0.50 1 0.49 0.42 1.11 1.55 0.10 0.27 0.38 Total 2.73 0.68 1.80 2.51 SAND&GREASE TRAP No.of S&G Baffle "Flow Rate, Throat Velocity, Velocity Vault Size Traps Spacing Throat Width Throat Area Q25 V Flow Rate Check Check (galon) (inch) (inch) (ft2) (cfs) (fps) Q25<3.33 cfs V<0.5 fps 1000 1 20 48 6.67 1.39 0.21 TRUE TRUE STORAGE VOLUMES Chamber 1 Req'd Volume, Pipe Volume, Rock Void Storage Volume, V2-YR Ll Wl dl VP1 Volume,VRi Vl (ft') (ft) (ft) (ft) (ft') (ft') (ft') 1,278 110 9 3.3 193 1,230 1,422 Chamber 2 Design Req'd Volume,Vl,,- Pipe Volume, Rock Void Infiltration Rate, Bed Infiltration Storage Time to YR L2 W2 d2 VP2 Volume,Vft2 I Volume,V21 Volume,V2 Drain 90% (ft') (ft) (ft) (ft) (ft') (ft') (in/hr) (ft') (ft') (hrs) 4,717 110 32.5 3.3 86 4,685 1.0 298 5,068 14.25 "NOTE:THERE ARE TWO GREASE TRAP PROPOSED FOR THIS BASIN WITH A Q25 OF 0.42 CFS&1.39 CFS SECTION 5 Swale Calculations Oaks North -Phase 13 By: KLP City of Meridian Date:7/10/2023 Ada County, Idaho Swale A Contributing Area Data Drainage Area(Ac.)= 0.23 Runoff Coefficient'c'= 0.50 Percolation Bed Data Sand Window Length(ft)= 42 Swale Slope= 0.50% Sand Window Width(ft)= 3.75 Swale Depth(ft)= 1.5 Sand Window Depth(ft)= 3.5 Swale Volume(cf)(4)= 567 Bottom Infiltration Area(sf)= 157.5 Sand Window Volume(cf)= 551 Infiltration Rate(in/hr)= 1.00 Voids(%)= 25% Available Sand Storage(cf)= 138 Total Volume[Swale Storage+ 705 Sand Storage](cf)_ Storage Storm Duration Storm Intensity Runoff Volume Percolated Volume Z (mins) Duration(hrs) (in/hr)(1) Peak Flow(cfs) (cf)(2) Volume(cf)(3) Needed LJJ (cf) > 10 0.17 2.58 0.30 178 2 176 LIJ 15 0.25 2.18 0.25 226 3 222 20 0.33 1.81 0.21 250 4 245 25 0.42 1.58 0.18 273 5 267 30 0.50 1.51 0.17 313 7 306 O 35 0.58 1.25 0.14 302 8 294 N40 0.67 1.15 0.13 317 9 309 45 0.75 1.07 0.12 332 10 322 50 0.83 1.00 0.12 345 11 334 Q 55 0.92 0.96 0.11 364 12 352 LLj 60 1 0.96 0.11 397 13 384 120 2 0.54 0.06 447 26 421 Q 180 3 0.40 0.05 497 39 457 Q 360 6 0.25 0.03 621 79 542 T-4 720 12 0.16 0.02 795 158 637 1440 24 0.10 0.01 994 315 679 MAXIMUM STORAGE VOLUME(CF)= 679 PROVIDED STORAGE(CF)= 705 DRAINAGE TIME(HRS)= 46.5 (less than 48 hours) NOTES: (1)Intensity from ACHD Intensity-Duration-Frequency Table in the ACHD Ordinance Section 8200-ACHD Stormwater Design Tools and Approved BMPs,Appendix A(Last Revsied 2020) (2)Runoff Volume=Peak Flow x Storm Duration x 3600 (3)Percolated Volume=Bottom Infiltration Area x(Infiltration Rate/12)x Storm Duration (4)Swale volume=Storage volume in the swale at 1.5'depth with 0.5'of freeoard Oaks North -Phase 13 By: KLP City of Meridian Date:7/10/2023 Ada County, Idaho Swale B Contributing Area Data Drainage Area(Ac.)= 0.26 Runoff Coefficient'c'= 0.50 Percolation Bed Data Sand Window Length(ft)= 90 Swale Slope= 0.50% Sand Window Width(ft)= 2.00 Swale Depth(ft)= 1.5 Sand Window Depth(ft)= 1 Swale Volume(cf)(4)= 979 Bottom Infiltration Area(sf)= 180.0 Sand Window Volume(cf)= 180 Infiltration Rate(in/hr)= 1.00 Voids(%)= 25% Available Sand Storage(cf)= 45 Total Volume[Swale Storage+ 1,024 Sand Storage](cf)_ Storage Storm Duration Storm Intensity Runoff Volume Percolated Volume Z (mins) Duration(hrs) (in/hr)(1) Peak Flow(cfs) (cf)(2) Volume(cf)(3) Needed LLI (cf) > 10 0.17 2.58 0.34 201 3 199 LIJ 15 0.25 2.18 0.28 255 4 251 20 0.33 1.81 0.24 282 5 277 25 0.42 1.58 0.21 308 6 302 30 0.50 1.51 0.20 353 8 346 O 35 0.58 1.25 0.16 341 9 333 N40 0.67 1.15 0.15 359 10 349 45 0.75 1.07 0.14 376 11 364 50 0.83 1.00 0.13 390 13 378 Q 55 0.92 0.96 0.12 412 14 398 W 60 1 0.96 0.12 449 15 434 120 2 0.54 0.07 505 30 475 Q 180 3 0.40 0.05 562 45 517 Q 360 6 0.25 0.03 702 90 612 T-4 720 12 0.16 0.02 899 180 719 1440 24 0.10 0.01 1,123 360 763 MAXIMUM STORAGE VOLUME(CF)= 763 PROVIDED STORAGE(CF)= 1,024 DRAINAGE TIME(HRS)= 45.8 (less than 48 hours) NOTES: (1)Intensity from ACHD Intensity-Duration-Frequency Table in the ACHD Ordinance Section 8200-ACHD Stormwater Design Tools and Approved BMPs,Appendix A(Last Revsied 2020) (2)Runoff Volume=Peak Flow x Storm Duration x 3600 (3)Percolated Volume=Bottom Infiltration Area x(Infiltration Rate/12)x Storm Duration (4)Swale volume=Storage volume in the swale at 1.5'depth with 0.5'of freeoard SECTION 6 Intensity-Duration-Frequency Curve ACHD Intensity-Duration-Frequency Intensity(inches per hour) Design Storm 2 5 10 25 50 100 Tc(hr) Tc(min) 0.17 10 0.69 1.15 1.48 1.85 2.20 2.58 0.25 15 0.59 0.97 1.22 1.56 1.86 2.18 0.33 20 0.49 0.81 1.01 1.30 1.54 1.81 0.42 25 0.43 0.71 0.89 1.14 1.35 1.58 0.50 30 0.41 0.67 0.85 1.08 1.29 1.51 0.58 35 0.34 0.56 0.70 0.90 1.07 1.25 0.67 40 0.31 0.51 0.64 0.82 0.98 1.15 0.75 45 0.29 0.48 0.60 0.77 0.91 1.07 0.83 50 0.27 0.45 0.56 0.72 0.85 1.00 0.92 55 0.26 0.43 0.54 0.69 0.82 0.96 1 60 0.26 0.43 0.54 0.69 0.82 0.96 2 120 0.16 0.25 0.31 0.39 0.46 0.54 3 180 0.13 0.19 0.23 0.29 0.34 0.40 6 360 0.09 0.12 0.14 0.18 0.21 0.25 12 720 0.06 0.08 0.10 0.12 0.14 0.16 24 1440 1 0.04 0.06 1 0.06 0.08 1 0.09 0.10 Intensity Duration Frequency ------ 2 3 -)K-5 -x-10 2.5 25 t 50 2 ---0-100 L H u 1.5 c c c �X�X X----X_X\X_X- --~-- \X-_)K X- �X-X 0.5 ------ ---------X-X-X- \ _ 0 - - ---- 10 15 20 25 30 35 40 45 50 55 60 120 180 360 720 1440 Duration(minutes) SECTION 7 Pipe Flow Calculations Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CB Al to SDMH A7 - 25yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.21 Q (cfs) = 0.270 Area (sqft) = 0.12 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.23 Slope (%) = 0.40 Wetted Perim (ft) = 0.95 N-Value = 0.010 Crit Depth, Yc (ft) = 0.22 Top Width (ft) = 0.82 Calculations EGL (ft) = 0.29 Compute by: Known Q Known Q (cfs) = 0.27 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CB A2 to SDMH A7 - 25yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.30 Q (cfs) = 0.560 Area (sqft) = 0.20 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.82 Slope (%) = 0.40 Wetted Perim (ft) = 1.16 N-Value = 0.010 Crit Depth, Yc (ft) = 0.31 Top Width (ft) = 0.92 Calculations EGL (ft) = 0.42 Compute by: Known Q Known Q (cfs) = 0.56 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CB A3 to SDMH A6 - 25yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.22 Q (cfs) = 0.290 Area (sqft) = 0.13 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.24 Slope (%) = 0.40 Wetted Perim (ft) = 0.98 N-Value = 0.010 Crit Depth, Yc (ft) = 0.23 Top Width (ft) = 0.83 Calculations EGL (ft) = 0.30 Compute by: Known Q Known Q (cfs) = 0.29 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CB A4 to SDMH A6 - 25yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.21 Q (cfs) = 0.270 Area (sqft) = 0.12 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.23 Slope (%) = 0.40 Wetted Perim (ft) = 0.95 N-Value = 0.010 Crit Depth, Yc (ft) = 0.22 Top Width (ft) = 0.82 Calculations EGL (ft) = 0.29 Compute by: Known Q Known Q (cfs) = 0.27 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 SDMH A7 to SDMH A5 - 25yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.30 Q (cfs) = 0.830 Area (sqft) = 0.20 Invert Elev (ft) = 100.00 Velocity (ft/s) = 4.18 Slope (%) = 0.93 Wetted Perim (ft) = 1.16 N-Value = 0.010 Crit Depth, Yc (ft) = 0.39 Top Width (ft) = 0.92 Calculations EGL (ft) = 0.57 Compute by: Known Q Known Q (cfs) = 0.83 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 SDMH A6 to SDMH A5 - 25yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.30 Q (cfs) = 0.560 Area (sqft) = 0.20 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.82 Slope (%) = 0.40 Wetted Perim (ft) = 1.16 N-Value = 0.010 Crit Depth, Yc (ft) = 0.31 Top Width (ft) = 0.92 Calculations EGL (ft) = 0.42 Compute by: Known Q Known Q (cfs) = 0.56 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 SDMH A5 to SDMH A4 - 25yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.34 Q (cfs) = 1.390 Area (sqft) = 0.24 Invert Elev (ft) = 100.00 Velocity (ft/s) = 5.85 Slope (%) = 1.44 Wetted Perim (ft) = 1.25 N-Value = 0.010 Crit Depth, Yc (ft) = 0.50 Top Width (ft) = 0.95 Calculations EGL (ft) = 0.87 Compute by: Known Q Known Q (cfs) = 1.39 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CB A6 to CB A5 - 25yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.19 Q (cfs) = 0.230 Area (sqft) = 0.10 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.19 Slope (%) = 0.40 Wetted Perim (ft) = 0.90 N-Value = 0.010 Crit Depth, Yc (ft) = 0.20 Top Width (ft) = 0.79 Calculations EGL (ft) = 0.26 Compute by: Known Q Known Q (cfs) = 0.23 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CB A5 to SDMH A2 - 25yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.26 Q (cfs) = 0.420 Area (sqft) = 0.16 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.56 Slope (%) = 0.40 Wetted Perim (ft) = 1.07 N-Value = 0.010 Crit Depth, Yc (ft) = 0.27 Top Width (ft) = 0.88 Calculations EGL (ft) = 0.36 Compute by: Known Q Known Q (cfs) = 0.42 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CB Al to SDMH A7 - 100yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.25 Q (cfs) = 0.380 Area (sqft) = 0.15 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.46 Slope (%) = 0.40 Wetted Perim (ft) = 1.05 N-Value = 0.010 Crit Depth, Yc (ft) = 0.26 Top Width (ft) = 0.87 Calculations EGL (ft) = 0.34 Compute by: Known Q Known Q (cfs) = 0.38 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CBA2toSDMHA7 - 100yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.36 Q (cfs) = 0.780 Area (sqft) = 0.26 Invert Elev (ft) = 100.00 Velocity (ft/s) = 3.05 Slope (%) = 0.40 Wetted Perim (ft) = 1.29 N-Value = 0.010 Crit Depth, Yc (ft) = 0.37 Top Width (ft) = 0.96 Calculations EGL (ft) = 0.50 Compute by: Known Q Known Q (cfs) = 0.78 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CBA3toSDMHA6 - 100yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.25 Q (cfs) = 0.400 Area (sqft) = 0.15 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.59 Slope (%) = 0.40 Wetted Perim (ft) = 1.05 N-Value = 0.010 Crit Depth, Yc (ft) = 0.26 Top Width (ft) = 0.87 Calculations EGL (ft) = 0.35 Compute by: Known Q Known Q (cfs) = 0.40 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CBA4toSDMHA6 - 100yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.24 Q (cfs) = 0.370 Area (sqft) = 0.15 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.55 Slope (%) = 0.40 Wetted Perim (ft) = 1.02 N-Value = 0.010 Crit Depth, Yc (ft) = 0.25 Top Width (ft) = 0.85 Calculations EGL (ft) = 0.34 Compute by: Known Q Known Q (cfs) = 0.37 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 SDMH A7 to SDMH A5 - 100yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.35 Q (cfs) = 1.160 Area (sqft) = 0.25 Invert Elev (ft) = 100.00 Velocity (ft/s) = 4.70 Slope (%) = 0.93 Wetted Perim (ft) = 1.27 N-Value = 0.010 Crit Depth, Yc (ft) = 0.46 Top Width (ft) = 0.96 Calculations EGL (ft) = 0.69 Compute by: Known Q Known Q (cfs) = 1.16 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 SDMH A6 to SDMH A5 - 100yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.35 Q (cfs) = 0.770 Area (sqft) = 0.25 Invert Elev (ft) = 100.00 Velocity (ft/s) = 3.12 Slope (%) = 0.40 Wetted Perim (ft) = 1.27 N-Value = 0.010 Crit Depth, Yc (ft) = 0.37 Top Width (ft) = 0.96 Calculations EGL (ft) = 0.50 Compute by: Known Q Known Q (cfs) = 0.77 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 SDMH A5 to SDMH A4 - 100yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.41 Q (cfs) = 1.930 Area (sqft) = 0.30 Invert Elev (ft) = 100.00 Velocity (ft/s) = 6.36 Slope (%) = 1.44 Wetted Perim (ft) = 1.39 N-Value = 0.010 Crit Depth, Yc (ft) = 0.60 Top Width (ft) = 0.98 Calculations EGL (ft) = 1.04 Compute by: Known Q Known Q (cfs) = 1.93 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 Nor 0.50 100.00 0.00 99.50 —0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CB A6 to CB A5 - 100yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.23 Q (cfs) = 0.320 Area (sqft) = 0.14 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.32 Slope (%) = 0.40 Wetted Perim (ft) = 1.00 N-Value = 0.010 Crit Depth, Yc (ft) = 0.24 Top Width (ft) = 0.84 Calculations EGL (ft) = 0.31 Compute by: Known Q Known Q (cfs) = 0.32 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 v 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) Channel Report Hydraflow Express Extension for Autodesk®Civil 3D®by Autodesk, Inc. Wednesday,Jul 19 2023 CBA5toSDMHA2 - 100yr Circular Highlighted Diameter (ft) = 1.00 Depth (ft) = 0.31 Q (cfs) = 0.580 Area (sqft) = 0.21 Invert Elev (ft) = 100.00 Velocity (ft/s) = 2.77 Slope (%) = 0.40 Wetted Perim (ft) = 1.18 N-Value = 0.010 Crit Depth, Yc (ft) = 0.32 Top Width (ft) = 0.93 Calculations EGL (ft) = 0.43 Compute by: Known Q Known Q (cfs) = 0.58 Elev (ft) Section Depth (ft) 102.00 2.00 101.50 1.50 101.00 1.00 100.50 0.50 100.00 0.00 99.50 -0.50 0 1 2 3 Reach (ft) SECTION 8 Drainage Basin Map /) J v IVI F Z W 0 N 0 n � F7:i, FL 10 �l I W I� / 2 Z / \ 25 m n > /�� vC/) < «o a I I��IIII� i a ..N C • I � � U N N t3 / / 22 Z © \ / 16 O 23 I 24 \ J O J N I BLOCK 3 n n n Z m PI- Pi 11 INLET A4 _ I Z PREVIOUSLY INLET Al 0�29 z APPROVED AS Swae � I W PART OF PHASE 0.23 IN:LET A3 7 INLET A2 I I I 1.01 � i I I i IQ m i Swale B J o INLET A6 0.26 I F z 0.24 U !n !t z C BLOCK 14 O BLOCK 16 P P X o > O N P P ti s P P (n 11 13 14 is is 17 18 Q O O O _ P —p rQ ml �x�,� 2x2-1 2x2-1 © —P x o N x I — I I x 3x1/ N � 7 P I o D p — z — m I I Q P P P P P P P P P P P P P P P P P �I J M z I I I I I I I I I I pIpIPIIP U S W. J SEPH DR. _ — IS S S S �� �1 I I I 1 .I 1 1 W M I I 1 1. 1 1 1 1 1 P"1 I I I I I I � Z O z = Q U ~ Y0� Q o5m w 0 W0� z m� Q �y� N � o N U W (n FEET DATE: SCALE: 80 0 40 80 160 s/za/z1 AS NOTED MRZ GRF JOB NO.: FILE NAME: GRAPHIC SCALE 1 inch = 80 ft. 4468 468-S-SNM-PHl SHEEP NO.: OF