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Home My WebLink AboutSW4231001_Stormwater Narrative_20231023 STORMWATER NARRATIVE AND DESIGN CALCULATIONS For: Word of Life Church Forsyth County, North Carolina ADI Project No. 23-032 tt� 'u^c• ttaiii EAL ��/ 19701 a Developer: •<�jy ��. � T SINE SF, �,' Bruce Henry, Sr. & Lydia Henry M.CP� 2048 Bethania Rural Hall Road Winston- Salem,NC 27106 Prepared by: Allied Design,Inc. 4720 Kester Mill Road Winston-Salem,NC 27103 (336) 765-2377 scausey@allied-engsurv.com A STORMWATER NARRATIVE WORD OF LIFE CHURCH TABLE OF CONTENTS A. Introduction B. Methodology C. Site Design and Assessment D. Conclusion Appendix A. NOAA Rainfall Data (Hydraflow Rainfall Report) B. Curve Number Summary C. Bioretention Cell Calculations D. 1-Year/24 Hour Frequency Design Storm Hydrographs E. 100-Year Frequency Design Storm Hydrographs F. Hydrograph Recap Report G. Pond Report H. Outlet Stabilization Calculations I. Ditch Calculations J. USDA Soils Report K. National Wetlands Inventory Wetlands Delineation L. Soil/Site Evaluations for Seasonal High Ground Water Table Allied Design Inc. Project No.: 22-017 Page 1 STORMWATER NARRATIVE WORD OF LIFE CHURCH A. Introduction The Word of Life Church consists of a 3.25-acre parcel of property located along Montford Road in Pfafftown, North Carolina. The development proposes a new building addition, a gravel and concrete parking lot, and two driveways. In accordance with the requirements of NCDEQ Post Construction Stormwater program, the project will require a stormwater management permit for quality management. Appropriate soil media, sod, and an underdrain system will be provided in accordance with the requirements of the BMP Manual. The bioretention cell's design for the project area was sized based on the capture of the first 1-inch of runoff in a ponding depth of 12 inches over the surface area of the cell. Stormwater management permit approval will require design and construction of a permanent water quality measure to manage the runoff from all new impervious coverage. The stormwater management plan for the Word of Life Church utilizes a bioretention cell (bio cell) as the primary Stormwater Control Measure (SCM) to meet NCDEQ's post construction stormwater management requirements. The bio cell will be designed to treat the first 1-inch of runoff for quality treatment. B. Methodology Reference for preparation of the stormwater management plan is made to the North Carolina Division of Environmental Quality's "New Stormwater Design Manual" (MDC's). City/County topographical maps, site surveys, and the proposed site development plans were utilized to delineate the post-development runoff patterns. The USDA Soils Survey was referenced and used to determine the Runoff Curve Numbers (CN's). The storm events modeled in this design are based on the SCS 24 Hour Storm Distribution for the 1-year storm and the 6 Hour Storm Distribution for 100-year Allied Design Inc. Project No.: 22-017 Page 2 STORMWATER NARRATIVE WORD OF LIFE CHURCH design storm. The Intensity-Duration Frequency Curves were established using the FHA Method. Precipitation frequency estimates were obtained from NOAA. Inflow hydrographs were derived from the SCS Unit Hydrograph Method and routed through the proposed wet detention basin. The Storage Indication Method is used to determine and verify design of the primary outlet structure. "Hydraflow Hydrographs", 2004 edition software was used to perform the routing calculations. The bio cell design is based on capture of the first 1-inch of runoff. The required surface area and volume is calculated based on the simple method. The bio cell will utilize a precast concrete outlet structure with a cast in place drop inlet to control the post-developed runoff rates from the 1-year, 24-Hour storm event to a runoff rate that minimizes hydrologic impacts to the receiving stream. The outlet structure is modeled to assume 50% blockage of the overflow weir. The proposed detention is designed to ensure the maximum storage elevation during the 100-year storm remains at least 1 foot below the top of dam elevation. C. Conclusion This Stormwater Narrative concludes that the project is being developed in accordance with the Bioretention Cell (C-2) provisions of the MDC. As indicated by the stormwater management plans and calculations included in this report, stormwater quality treatment is being provided on-site in accordance with NCDEQ's stormwater management requirements. 1. Stormwater Quality Management The drainage area routed to the wet detention basin includes 1.46 acres with approximately 0.88 acres being impervious. No offsite area will be managed by the proposed SCM. The bio cell captures the first 1-inch of runoff from the post-developed drainage areas and treats the flow in accordance with the requirements of the NCDEQ's Stormwater Allied Design Inc. Project No.: 22-017 Page 3 STORMWATER NARRATIVE WORD OF LIFE CHURCH Design Manual. The routing hydrographs included in this report also verify that the post-developed runoff for the 1-yr 24-hr water quality event to a runoff rate that minimizes hydrologic impacts to the receiving stream. A summary of the water quality management is provided as follows: Summary of Water Quality Management Management Aspects Pond 1 Required Provided Water Quality Volume (cf) 3,140 4,320 Water Quality Elevation (ft) 917 917 Water Quality Surface Area (sf) 3,140 3,520 Allied Design Inc. Project No.: 22-017 Page 4 STORMWATER NARRATIVE WORD OF LIFE CHURCH Appendix Allied Design Inc. Project No.: 22-017 Page 5 A . Hydraflow Rainfall Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2024 Monday,09/11 /2023 Return Intensity-Duration-Frequency Equation Coefficients(FHA) Period (Yrs) B D E (N/A) 1 55.5150 12.5000 0.8837 2 0.0000 0.0000 0.0000 3 0.0000 0.0000 0.0000 5 0.0000 0.0000 0.0000 10 0.0000 0.0000 0.0000 25 0.0000 0.0000 0.0000 50 0.0000 0.0000 0.0000 100 47.9561 8.9000 0.6494 File name:Winston-Salem-Fiddlers Landing.IDF Intensity= B/(Tc+ D)^E Return Intensity Values(in/hr) Period (Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60 1 4.42 3.54 2.97 2.56 2.26 2.02 1.83 1.68 1.55 1.44 1.34 1.26 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 25 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100 8.68 7.11 6.11 5.40 4.87 4.45 4.11 3.84 3.60 3.40 3.22 3.07 Tc=time in minutes.Values may exceed 60. \21-014 Fiddlers Landing Thomasville Road-LeoTerra\admin\SWM\Hydraflow\Winston-Salem-Gatehouse Manor.pcp Rainfall Precipitation Table (in) Storm Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCS 24-hour 2.84 3.39 0.00 4.22 4.90 0.00 6.57 0.00 SCS 6-Hr 0.00 2.38 0.00 2.92 3.43 4.12 4.48 5.20 Huff-1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Custom 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 B . POST-DEVELOPMENT CURVE NUMBER CALCULATIONS POI 1 POST DEVELOPMENT TO SAND FILTER TYPE OF AREA SOIL GROUP CN CN AREA POI TOTAL AREA %POI %CN WEIGHTED CN ONSITE OPEN SPACE(GOOD) A 39 0.29 AC 19.86% 7.7 ONSITE OPEN SPACE(GOOD) B 61 0.29 AC 1.46 AC 19.86% 12.1 79 ONSITE IMPERVIOUS B 98 0.88 AC 60.27% 59.1 IMPERVIOUS AREA 60% C . Bio Cell Design Calculation Sheet Bioretention Cell #1 Word of Life Church September 8, 2023 Site Information Drainage Area (Ad) = 1.46 ac Impervious area (Al) = 0.88 ac Impervious % IA = 60% Runoff Coefficient (Rv)= 0.592465753 Determine 1 inch Water Quality Volume (WQV) Design Storm Depth (RD) = 1 in Depth of Media 2.50 ft Time Required to Drain WQV 1.13 days Coefficient of Permeability 4.00 ft/day Min. Treatment Volume: 3,140 cf Determine Required Surface Area Design Volume (DV) = 3,140 cf Ponding Depth 1 .00 ft Required Surface Area = 3,140 sf Determine Required Surface Area Proposed Design Volume (Dv) = 4,354 cf Proposed Surface Area = 3,520 sf Underdrain Design Assumed Underdrain Clogging Percentage 50.00% Number of Rows 4 rows Length of Runs 5.00 ft Computed Min. Drawdown Discharge 0.025 cfs Computed Stage-Discharge for Filter Media 0.166 cfs Perforation Capacity Number of Perforations 160 Perforations After Clogging 80 Capacity of One Hole 0.004 cfs/hole Computed Total Perforation Capacity 0.31 cfs Perf. Capacity > Filter Media Capacity/ ACCEPTABLE Mininmum Drawdown Capacity Pipe Capacity Computed Underdrain Pipe Size 8.93 in Assumed Underdrain Pipe Size 6 in Confirmed Underdrain Pipe Capacity 0.57 cfs Pipe Capacity > Filter Media Capacity/ ACCEPTABLE Mininmum Drawdown Capacity D . Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk,Inc.v2024 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) I 1 SCS Runoff 2.665 2 718 5,331 POST DEVELOPMENT 1 YR 24 HO 3 SCS Runoff 0.000 2 n/a 0 POST DEVELOPMENT 100 YR 6 HR 5 Reservoir 0.062 2 956 1,417 1 917.01 3,985 <no description> 7 Reservoir 0.000 2 n/a 0 3 916.00 0.000 <no description> bio cell.gpw Return Period: 1 Year Monday, 09/ 11 /2023 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2024 Monday,09/11 /2023 Hyd. No. 1 POST DEVELOPMENT 1 YR 24 HOUR Hydrograph type = SCS Runoff Peak discharge = 2.665 cfs Storm frequency = 1 yrs Time to peak = 11.97 hrs Time interval = 2 min Hyd. volume = 5,331 cuft Drainage area = 1.460 ac Curve number = 79 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 2.84 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 POST DEVELOPMENT 1 YR 24 HOUR Q (cfs) Hyd. No. 1 -- 1 Year Q (cfs) 3.00 3.00 2.00 2.00 1.00 1.00 0.00 1 L 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 1 Time (hrs) Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2024 Monday,09/11 /2023 Hyd. No. 5 <no description> Hydrograph type = Reservoir Peak discharge = 0.062 cfs Storm frequency = 1 yrs Time to peak = 15.93 hrs Time interval = 2 min Hyd. volume = 1,417 cuft Inflow hyd. No. = 1 - POST DEVELOPMENT 1 Y Ra24ffitt n = 917.01 ft Reservoir name = bio cell Max. Storage = 3,985 cuft Storage Indication method used. <no description> Q (cfs) Hyd. No. 5 -- 1 Year Q (cfs) 3.00 � 3.00 2.00 2.00 1.00 1.00 0.00 L 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Time (hrs) Hyd No. 5 Hyd No. 1 1111111 Total storage used = 3,985 cuft E . Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk,Inc.v2024 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) I 1 SCS Runoff 0.000 2 n/a 0 POST DEVELOPMENT 1 YR 24 HO 3 SCS Runoff 3.727 2 144 14,779 POST DEVELOPMENT 100 YR 6 HR 5 Reservoir 0.000 2 n/a 0 1 916.00 0.000 <no description> 7 Reservoir 2.169 2 156 10,865 3 917.30 5,362 <no description> bio cell.gpw Return Period: 100 Year Monday, 09/ 11 /2023 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2024 Monday,09/11 /2023 Hyd. No. 3 POST DEVELOPMENT 100 YR 6 HR Hydrograph type = SCS Runoff Peak discharge = 3.727 cfs Storm frequency = 100 yrs Time to peak = 2.40 hrs Time interval = 2 min Hyd. volume = 14,779 cuft Drainage area = 1.460 ac Curve number = 79 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 5.20 in Distribution = SCS 6-Hr Storm duration = 6.00 hrs Shape factor = 484 POST DEVELOPMENT 100 YR 6 HR Q (cfs) Hyd. No. 3-- 100 Year Q (cfs) 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 ,- 0.00 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Hyd No. 3 Time (hrs) Hydrograph Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2024 Monday,09/11 /2023 Hyd. No. 7 <no description> Hydrograph type = Reservoir Peak discharge = 2.169 cfs Storm frequency = 100 yrs Time to peak = 2.60 hrs Time interval = 2 min Hyd. volume = 10,865 cuft Inflow hyd. No. = 3 - POST DEVELOPMENT 109R flldR3tion = 917.30 ft Reservoir name = bio cell Max. Storage = 5,362 cuft Storage Indication method used. <no description> Q (cfs) Hyd. No. 7-- 100 Year Q (cfs) 4.00 4.00 3.00 3.00 2.00 ' 2.00 1.00 1.00 ,I ____ 0.00 _ 1 - 0.00 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Time (hrs) Hyd No. 7 Hyd No. 3 1111111 Total storage used = 5,362 cuft F . Hydrograph Return Period Recap draflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk,Inc.v2024 Hyd. Hydrograph Inflow Peak Outflow(cfs) Hydrograph No. type hyd(s) Description (origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr 1 SCS Runoff 2.665 0.000 POST DEVELOPMENT 1 YR 24 HO 3 SCS Runoff 0.000 3.727 POST DEVELOPMENT 100 YR 6 HR 5 Reservoir 1 0.062 0.000 <no description> 7 Reservoir 3 0.000 2.169 <no description> Proj. file: bio cell.gpw Monday, 09/ 11 /2023 G . Pond Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2024 Monday,09/11 /2023 Pond No. 1 - bio cell Pond Data Contours-User-defined contour areas.Conic method used for volume calculation.Begining Elevation=916.00 ft Stage/Storage Table Stage(ft) Elevation(ft) Contour area(sqft) Incr.Storage(cuft) Total storage(cuft) 0.00 916.00 3,521 0 0 1.00 917.00 4,319 3,913 3,913 2.00 918.00 5,426 4,862 8,774 2.50 918.50 5,950 2,843 11,617 Culvert/Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise(in) = 15.00 0.00 0.00 0.00 Crest Len(ft) = 4.00 0.00 0.00 0.00 Span(in) = 15.00 0.00 0.00 0.00 Crest El.(ft) = 917.00 0.00 0.00 0.00 No.Barrels = 1 0 0 0 Weir Coeff. = 3.33 3.33 3.33 3.33 Invert El.(ft) = 911.85 0.00 0.00 0.00 Weir Type = 1 --- --- --- Length(ft) = 41.00 0.00 0.00 0.00 Multi-Stage = Yes No No No Slope(%) = 2.08 0.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000(by Contour) Multi-Stage = n/a No No No TW Elev.(ft) = 0.00 Note:Culvert/Orifice outflows are analyzed under inlet(ic)and outlet(oc)control. Weir risers checked for orifice conditions(ic)and submergence(s). Stage(ft) Stage/ Discharge Elev(ft) 3.00 919.00 2.00 918.00 1.00 917.00 0.00 916.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 Total Q Discharge(cfs) H . I . VEGETATED CONVEYANCE SCHEDULE-25 YEAR DESIGN STORM SHERWOOD ESTATES YADKIN COUNTY,NORTH CAROLINA 6/29/2023 VEGETATED DRAINAGE INLET RUNOFF TIME OF LINING INTENSITY DISCHARGE DITCH BOTTOM LENGTH SIDE DEPTH OF VELOCITY STAPLE PATTERN CONVEYANCE AREA COEFFICENT CONCENTRATION SLOPE WIDTH SLOPES FLOW MATERIAL 0.08 FT 1.81 F/S S150 D #1 0.07 AC 0.6 5.00 MIN 7.64 IN/HR 0.32 CFS 10.00% 2.00 FT 60.00 FT 3:1 0.07 FT 2.14 F/S S75 D 0.08 FT 1.83 F/S GRASS N/A 0.06 FT 1.32 F/S S150 D #2 0.10 AC 0.6 5.00 MIN 7.64 IN/HR 0.46 CFS 9.00% 6.00 FT 30.00 FT 3:1 0.05 FT 1.59 F/S S75 D 0.06 FT 1.26 F/S GRASS N/A 0.22 FT 0.70 F/S S150 D #3 0.09 AC 0.6 5.00 MIN 7.64 IN/HR 0.41 CFS 1.20% 2.00 FT 80.00 FT 3:1 0.17 FT 0.96 F/S S75 D 0.24 FT 0.64 F/S GRASS N/A NORTH North American Green AMERICAN 5401 St. Wendel-Cynthiana Rd. Poseyville, Indiana 47633 GREEN Tel. 800.772.2040 >Fax 812.867.0247 www.nagreen.com ECMDS v7.0 CHANNEL ANALYSIS >>>DITCH#1 Name DITCH#1 Discharge 0.32 Channel Slope 0.1 Channel Bottom Width 2 Left Side Slope 3 Right Side Slope 3 Low Flow Liner Retardence Class D 2-6 in Vegetation Type Mix(Sod and Bunch) Vegetation Density Very Good 80-95% Soil Type Clay Loam(CL) S150 Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Remarks Depth Mannings N Shear Stress Shear Stress Factor Pattern S150 Straight 0.32 cfs 1.81 ft/s 0.08 ft 0.044 1.8 lbs/ft2 0.49 lbs/ft2 3.67 STABLE D Unvegetated Underlying Straight 0.32 cfs 1.81 ft/s 0.08 ft 0.044 1.96 Ibs/ft2 0.44 Ibs/ft2 4.46 STABLE D Substrate S75 Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Remarks Depth Mannings N Shear Stress Shear Stress Factor Pattern S75 Unvegetated Straight 0.32 cfs 2.14 ft/s 0.07 ft 0.034 1.6 Ibs/ft2 0.42 Ibs/ft2 3.8 STABLE D Underlying Straight 0.32 cfs 2.14 ft/s 0.07 ft 0.034 1.74 lbs/ft2 0.38 lbs/ft2 4.56 STABLE D Substrate Unreinforced Vegetation Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Mannings N Remarks Depth Shear Stress Shear Stress Factor Pattern Unreinforced Straight 0.32 cfs 1.83 ft/s 0.08 ft 0.044 4 lbs/ft2 0.49 lbs/ft2 8.22 STABLE -- Vegetation Underlying Straight 0.32 cfs 1.83 ft/s 0.08 ft 0.044 4 Ibs/ft2 0.44 Ibs/ft2 9.17 STABLE -- Substrate NORTH North American Green AMERICAN 5401 St. Wendel-Cynthiana Rd. Poseyville, Indiana 47633 GREEN Tel. 800.772.2040 >Fax 812.867.0247 www.nagreen.com ECMDS v7.0 CHANNEL ANALYSIS >>>DITCH#2 Name DITCH#2 Discharge 0.46 Channel Slope 0.09 Channel Bottom Width 6 Left Side Slope 3 Right Side Slope 3 Low Flow Liner Retardence Class D 2-6 in Vegetation Type Mix(Sod and Bunch) Vegetation Density Very Good 80-95% Soil Type Clay Loam(CL) S150 Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Remarks Depth Mannings N Shear Stress Shear Stress Factor Pattern S150 Straight 0.46 cfs 1.32 ft/s 0.06 ft 0.049 1.8 lbs/ft2 0.32 lbs/ft2 5.66 STABLE D Unvegetated Underlying Straight 0.46 cfs 1.32 ft/s 0.06 ft 0.049 1.96 Ibs/ft2 0.31 Ibs/ft2 6.36 STABLE D Substrate S75 Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Remarks Depth Mannings N Shear Stress Shear Stress Factor Pattern S75 Unvegetated Straight 0.46 cfs 1.59 ft/s 0.05 ft 0.036 1.6 Ibs/ft2 0.26 Ibs/ft2 6.06 STABLE D Underlying Straight 0.46 cfs 1.59 ft/s 0.05 ft 0.036 1.74 lbs/ft2 0.26 lbs/ft2 6.77 STABLE D Substrate Unreinforced Vegetation Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Mannings N Remarks Depth Shear Stress Shear Stress Factor Pattern Unreinforced Straight 0.46 cfs 1.26 ft/s 0.06 ft 0.051 4 lbs/ft2 0.31 lbs/ft2 12.85 STABLE -- Vegetation Underlying Straight 0.46 cfs 1.26 ft/s 0.06 ft 0.051 4 Ibs/ft2 0.3 Ibs/ft2 13.24 STABLE -- Substrate NORTH North American Green AMERICAN 5401 St. Wendel-Cynthiana Rd. Poseyville, Indiana 47633 GREEN Tel. 800.772.2040 >Fax 812.867.0247 www.nagreen.com ECMDS v7.0 CHANNEL ANALYSIS >>>DITCH#3 Name DITCH#3 Discharge 0.41 Channel Slope 0.01 Channel Bottom Width 2 Left Side Slope 3 Right Side Slope 3 Low Flow Liner Retardence Class D 2-6 in Vegetation Type Mix(Sod and Bunch) Vegetation Density Very Good 80-95% Soil Type Clay Loam(CL) S150 Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Remarks Depth Mannings N Shear Stress Shear Stress Factor Pattern S150 Straight 0.41 cfs 0.7 ft/s 0.22 ft 0.066 1.8 lbs/ft2 0.14 lbs/ft2 13.11 STABLE D Unvegetated Underlying Straight 0.41 cfs 0.7 ft/s 0.22 ft 0.066 1.96 Ibs/ft2 0.11 Ibs/ft2 18.22 STABLE D Substrate S75 Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Remarks Depth Mannings N Shear Stress Shear Stress Factor Pattern S75 Unvegetated Straight 0.41 cfs 0.96 ft/s 0.17 ft 0.041 1.6 Ibs/ft2 0.11 Ibs/ft2 15.1 STABLE D Underlying Straight 0.41 cfs 0.96 ft/s 0.17 ft 0.041 1.74 lbs/ft2 0.09 lbs/ft2 20.15 STABLE D Substrate Unreinforced Vegetation Normal Permissible Calculated Safety Staple Phase Reach Discharge Velocity Mannings N Remarks Depth Shear Stress Shear Stress Factor Pattern Unreinforced Straight 0.41 cfs 0.64 ft/s 0.24 ft 0.075 4 lbs/ft2 0.15 lbs/ft2 27.19 STABLE -- Vegetation Underlying Straight 0.41 cfs 0.64 ft/s 0.24 ft 0.075 4 Ibs/ft2 0.11 Ibs/ft2 35.06 STABLE -- Substrate J . a Hydrologic Soil Group—Forsyth County,North Carolina a :CCC50 555580 550310 .C.C,040 555670 555700 555730 555760 555790 555820 555850 555880 36°11'46"N 36°11'46"N 0 .. <, pi • 401kik. 1 • , . „ . • • 6' A . \. ., •,.. 1 -.0.• . . \Ill 46'''''l . . . TmD1. raa� 47 .. A + . 11111 10 ii ,,. ,r CID - t0, , . g : ` � , �'�e Y J 1, 1' 1 FaF IC •Az; , ' ' „ .,J . ,; o X000 dap�a��oq bQ eaDo 7 a�ado �aOQ° ' � . — 36°11'38"N - 36°11'38"N 5513550 555680 350310 555640 555670 555700 555730 555760 555790 555820 555850 555880 3 3 NMap Scale:1:1,650 if printed on A landscape(11"x 8.5")sheet. N Meters $ N 0 20 40 80 120 8 Feet A0 50 100 200 300 Map projection:Web Mercator Corner coordinates:WG584 Edge tics:UTM Zone 17N WGS84 USDA Natural Resources Web Soil Survey 7/19/2023 dim Conservation Service National Cooperative Soil Survey Page 1 of 4 Hydrologic Soil Group—Forsyth County,North Carolina MAP LEGEND MAP INFORMATION Area of Interest(AOI) p c The soil surveys that comprise your AOI were mapped at Area of Interest(AOI) 1:15,800. 0 C/D Soils • D Warning:Soil Map may not be valid at this scale. Soil Rating Polygons l A p Not rated or not available Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil n A/D Water Features line placement.The maps do not show the small areas of Streams and Canals contrasting soils that could have been shown at a more detailed n B scale. Transportation Q B/D r4-1. Rails Please rely on the bar scale on each map sheet for map n C measurements. ti Interstate Highways C/D US Routes Source of Map: Natural Resources Conservation Service Web Soil Survey URL: 0 D Major Roads Coordinate System: Web Mercator(EPSG:3857) n Not rated or not available Local Roads Maps from the Web Soil Survey are based on the Web Mercator Soil Rating Lines Background projection,which preserves direction and shape but distorts • • A distance and area.A projection that preserves area,such as the 1111 Aerial Photography Albers equal-area conic projection,should be used if more • • A/D accurate calculations of distance or area are required. ^r B This product is generated from the USDA-NRCS certified data as .v B/D of the version date(s)listed below. • r C Soil Survey Area: Forsyth County, North Carolina Survey Area Data: Version 24,Sep 8,2022 • • C/D Soil map units are labeled(as space allows)for map scales • • D 1:50,000 or larger. • w Not rated or not available Date(s)aerial images were photographed: Oct 17,2020—Nov 3, Soil Rating Points 2020 p A The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background O A/D imagery displayed on these maps.As a result,some minor • B shifting of map unit boundaries may be evident. • B/D USDA Natural Resources Web Soil Survey 7/19/2023 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group—Forsyth County, North Carolina Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI CIB Clifford sandy loam,2 to A 0.4 4.3% 6 percent slopes CID Clifford sandy loam, 10 A 2.4 27.9% to 15 percent slopes FaF Fairview fine sandy B 0.1 0.9% loam, 15 to 45 percent slopes TmB Tomlin loam,2 to 6 B 2.2 25.0% percent slopes TmC Tomlin loam,6 to 10 B 3.1 35.5% percent slopes TmD Tomlin loam, 10 to 15 B 0.6 6.4% percent slopes Totals for Area of Interest 8.7 100.0% USDA Natural Resources Web Soil Survey 7/19/2023 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group—Forsyth County, North Carolina 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. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff.None Specified Tie-break Rule: Higher USDA Natural Resources Web Soil Survey 7/19/2023 Conservation Service National Cooperative Soil Survey Page 4 of 4 K . 1LV I•N'1IJ11JYN U.S. Fish and Wildlife Service Ell National Wetlands Inventor wetlands delineation :r: 1 . _ , l ,. . . . i _. ,, 10 11111‘, ' 11. ,ram As, •• • 6 I ,e d' • • el* — . ter -ter• f 4� . r �' , d 1. i u w. 7r A k , y s, • rn ■ • • k• • .�' 1`j— 'fly N� A . SITE -- t44 . . *101.. .... .. '.-14 '' f :: 4illr .4' Se . t ii. r %, ,, . • , , I- . .,1/4,_ - 1 . ,e, 4,, , 1.1„,,, . hift71'444.; ; '.-4 11110/44 . , 'f I 410. -. • • .... - 14 0.0A . .. - i 'as ' f . k i, . 1 el _ , .% , ., 1:3,762 ,• t 0 0.03 0.06 0.12 mi "1_ ' ' 4 ' '• 1' ' t �' J ' i i o 0 0 05 ti Oil O12 km 7r lei J. 1• 4 • .y, frp�+ p .dv '. ,ards i. • may,:- •� � i September 11, 2023 This map is for general reference only.The US Fish and Wildlife p Service is not responsible for the accuracy or currentness of the Wetlands base data shown on this map.All wetlands related data should Freshwater Emergent Wetland Lake be used in accordance with the layer metadata found on the Wetlands Mapper web site. Estuarine and Marine Deepwater Freshwater Forested/Shrub Wetland Other Estuarine and Marine Wetland I Freshwater Pond n Riverine I National Wetlands Inventory(NWI) This page was produced by the NWI mapper K . Alan Clapp Licensed Soil Scientist 389 Clapp Farms Road Greensboro, NC 27405 Phone:336-202-6808 alanclapp@aol.com Soil/Site Evaluations-Septic Systems Layout and Design-Storm water Assessment-Preliminary Evaluations October 11, 2023 Steve Causey Allied Design, Inc. 4720 Kester Mill Road Winston-Salem, North Carolina 27103 RE: Word of Life Project 4550 Montford Road PIN: 5899-22-5743 Forsyth County,NC Mr. Causey: On October 11, 2023, the property listed above in Forsyth County on Montford Road was evaluated at your request to determine the depth of the seasonally high-water table at two select storm water control measures (SCM) for a BMP device. Soil borings were used in the areas proposed for storm water devices (EG#A and EG#B)to serve the proposed development. The borings were advanced to satisfy requirements set forth in the North Carolina Division of Water Quality Stormwater Design Manual (NCDEQ Stormwater Design Manual A-2. Soils) and used standards as described in ASTM D-1452 for Seasonally High-Water Table determinations. Soil profile descriptions are described using Field Book for Describing and Sampling Soils (NRCS)with soil textures as defined using US Department of Agriculture (USDA)textural properties. This property is in the Piedmont physiographic region and the geologic region of the Milton terrane. The seasonal high-water table is determined by a field evaluation for soil wetness conditions. Soil wetness conditions are determined by the presence of redoximorphic (aka redox) features with a chroma of 2 or less (using the Munsell Soil Color Book) in mottles or the soil horizon matrix. Colors of chroma 2 or less due to relic minerals from the parent material (underlying rock), anaerobic activity created by placement of fill material or soil horizon/ soil textural transitions causing perching of water are not considered indicators of a seasonal high-water table. Soil borings were made in the vicinity of the BMP sand filter devices using an AMS hand auger. The boring locations were marked on the site with pink wire flags. GPS locations were located using EOS Arrow Gold GNSS device. Bore locations were made as close as possible to the prescribed plan locations using the coordinates collected with the handheld device. Project#: 923269 Findings: Borings were advanced in the prescribed location of the BMP device. The profiles were evaluated for the presence of a seasonally high-water table (SHWT). A boring data summary for the boring locations is listed in the table 1 below. A detailed soil boring profile description is included in table 2. Elevation and location data were inferred from the Design Plan from Allied Design for Word of Life Project on Mumford Road and as provided by Nicole Ellis. A SHWT was not found within 132" (11') of surface at the proposed BMP at EG#A or 84" (7') of surface at EG#B. Pleaselen feel free to contact me if you have any further questions. (tea,. C Alan Clapp Licensed Soil Scientist t A. ""'"eos\ ifiv SOIL SC/� 4:14'64• • �y-1144.4. ,,,y 1058 co, Table 1. Boring Data Summary Boring Beginning Total Bottom Proposed Elevation SHWT Location Surface Soil Elevation SCM to Depth # Elevation Bore of Boring Bottom SHWT from Boring+/- Depth +/- Elevation surface EG#A 920.9' 132" 909.9' Not > 132" (11') present at (11') from 909.9' surface EG#B 916.88' 84" 909.88' Not > 108" (7') present at (9') from 909.88' surface Project#: 923269 Table 2. Soil Profile Descriptions* Boring EG#A EG#B Location North: 892732.319 892780.722 Location East: 1592403.377 1592371.843 Soil Series: Clifford Clifford Landscape Position Linear- 6% Linear- 8% Horizon 1 (A) 0-12" (Fill) 0-18" Texture loam Matrix Color 5 YR 4/4 (reddish brown) Consistence/Structure/Mineralogy Friable, granular, 1:1 Horizon 2 (B) 12-78" (A) 18-22" Texture Clay loam Matrix Color 2.5 YR 3/6 (dark 5 YR 4/4 (reddish red) brown) Consistence/Structure/Mineralogy Firm, sbk, 1:1 Friable, granular, 1:1 Horizon 3 (BC) 78-132" (B) 22-82" Texture Clay clay Matrix Color 2.5YR 4/8 2.5 YR 3/6 (dark (red) red) Consistence/Structure/Mineralogy Firm, sbk, 1:1 Firm, sbk, 1:1 Horizon 4 82-108" Texture (BC) clay Matrix Colors 2.5YR 4/8 (red) Consistence/Structure/Mineralogy Firm, sbk, 1:1 Note: Quartz and Fill material placed Quartzite over a portion of throughout profile the area SHWT Depth from surface >132" (>11') >108" (>9') Reference texts: *Schoeneberger, P.J., Wysocki, D.A., Benham, E.C., and Broderson, W.D, 2002. Field book for describing and sampling soils, Version 2.0. National Resources Conservation Service,National Soil Survey Center, Lincoln,NE. All texture descriptions use USDA soil textures. Soil color descriptions are using Munsell Soil Color Charts Clifford soils: Fine, kaolinitic, mesic Typic Kanhapludults Project#: 923269 Locations: i-.1,.,;:v. ....t.r.!•:'.. ,... ;fr., 1 " ,•,.• As .Ar.;•°.:...4.:.•,:.:.:4. ,' e;:....... c-.... ::.i 41..:::^•' ,'•,. •:;.;:t.t.r.:ri....s.,•"..,„; m•%,..s.1.• .4"t'i?•"...r....v4sx.n.- •,••,•,, i ..• .• .t.,.". •1:46.J....;,k,:.4.". In I / ;.:1•4•.:r:e ‘.4.7: 51,4 c!",:\ ...1•;::•16:44.:":. / ••':.7.' i.ili.;'•••••Yo':'.1".c7";f:;.1...i...v.' • "il. e'::!!:"..i:.:P:*-•:;Y!..".4,,%17.1>!;:v:it;',4: ...f.,•:,:.-;I;AV.'''.t'..;.,...h?..?"i'14',...."0.4.•?'•!.:e*V. '.4.: I / ''"..,.....:1`.7..^.".. ' 4 1...4.143"}..... • •',.v:.7 :' 111/ (• 30.11::.:17.S.:t.;,:.•:%•4,44.i7..r:::::.S...;..4 ,tiC.. 1;4 \ "Ad 4.47...'1:4 ,•••••••/•14"X.,•..• ' '.V....1.14 '1•• ro x;"e:11 l'., '.i,.;:.;jr..rt.:...,:yja.:'•i.;1•44 • • 1! 1 s.;:i ce,"•.•:...,4ZK:';....(''.5 3.;•.:'!".1•.;:e•••;'..%,.1...F.; ...;•`.:". •'.. • • •,.::1.);o'xi f..I,,!..i!;%.01i.,..4.'tilsN'r"....r:: .;.:.4::...‘t..“),i•?f :;7:..ct.... • .:e.'.i.':•;4 1:•••.:.:4 Ak '5.:•••.4.:it:;...,:i;4?..;162:47: '':.1."5:li.:::1,:!:::::: •F .:":5 tessr'..Y.!'..:4:'..;:•=,,{fi'. :•::••t:t i ti.,7. : :....V.ISIi•j!" ..).,01.$6.. ',"!:`•,...,,,,.....I.o.?..':. I.. 1 1 \\ ...: j,....-..,..,,:...g.‘.;4...,:.,. .. ..f.v.-.....,e.::,.-...-::;. EG ..,..,....,...----:...........:0 ..s.e. LATITUDE: N36° 11'42.58" LONGITUDE:W80° 22'53.19" NORTHING:892780.722 ......:.,-.,-.. EASTING: 1592371.843 .:,../....... 4khkiv. EG: 916.88 1 \ <1...,..] FG: 909.85 Il• g2 II a u j LOLANGTITITUUDDEE:: N36°80 21\1\4522:8101: \\I EASTING: 1592403.377 I NORTHING: 892732.319 .. EG: 920.90 CV 11 r-: 1 7 •Ipti? 11 FG: 909.85 z il 1 1 \ Project#: 923269 Soil Horizon Profile Colors EG BMP #A and #B • 1 Project#: 923269