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SW6230103_Stormwater Report_20230523
STORMWATER MANAGEMENT AND TEMPORARY EROSION CONTROL for CARTER FARMS SUBDIVISION PHASE I Submittal to: NCDEQ PUBLIC WATER SUPPLY SECTION HOKE COUNTY, NORTH CAROLINA Submittal date: May 18, 2022 Owner/ Developer: Rheibeck Investments, LLC. 3727 Legion Road Hope Mills, NC 28348 Contact: Geoff Becker Phone: (910) 426-7575 Prepared by: Averette Engineering Co., P.A. CIVIL ENGINEERING Lddro LAND SURVEYING — 119 F. — PJJ_1e Ro-c f PLANNING ,t``j_ I;acford, FJL; 2E4376 P-ione,�B16) 458—�656 Fix:,, -3' 4D—-181 Es:ablishcc eb:v,•Nm�.ave�et�e enc.com TABLE OF CONTENTS SECTION PAGE I. EXISTING CONDITIONS A. PROPERTY ....................................................................................................1 B. WATERSHED .................................................................................................2 C. JURISDICTIONAL WATERS.................................................................................2 D. FEMA FLOOPLAIN... ....................................................................................2 E. SOILS............................................................................................................2 II. AGENCY STORMWATER REQUIREMENTS A. Hoke County.............................................................................................2 B. NCDEQ .........................................................................................................3 III. PROPOSED IMPROVEMENTS A. PROJECT DESCRIPTION.....................................................................................3 B. LAND DISTURBANCE AND EROSION CONTROL.......................................3 C. IMPERVIOUS SURFACE ...................................................................................3 D. DRAINAGE AND STORMWATER MANAGEMENT.......................................4 APPENDICES A. Computations Minor System Grass Conveyance Swales Erosion Control B. Maps Inlet Drainage Area Erosion Control Drainage Area C. Soil Survey Map D. FEMA FIRM Map E. USGS MAP F. STORMWATER FORMS SUPPLEMENT-EZ OPERATION &MAINTENANCE AGREEMENT BMP SUPPLEMENT FORMS I. EXISTING CONDITIONS A. PROPERTY The proposed project site is 28.11 AC project consisting of PIN#'s 7947-30-00-1348, 794730001062, 794730001316, 794730001294, 794730001295, 794730001293 respectively in Hoke County. The property is currently undeveloped farm land with no impervious surfaces. The property has a cell phone tower that is to be decommissioned as part of phase 2. The following is a summary of the adjacent properties: To the north, commercial chicken farm(zoning RA-20) To the south,single family (zoning RA-20) To the west, undeveloped (zoning RA-20) To the east, single family (zoning RA-20) See Figure 1 below for an aerial view of the property for the proposed Carter Farm Subdivision project (Site). Figure ]:Aerial view of pre-developed site �s 3 Za Stormwater Impact Analysis-Carter Farms Subdivision Page 1 1 4 B. WATERSHED The site is located in the Mill Creek Watershed and Cape Fear River Basin. The NCDEQ Stream Index for Mill Creek is 18-31-20 and Stream Classification for Mill Creek is `B'. C. JURISDICTIONAL WATERS There are no jurisdictional streams located on the site. There are no impacts proposed with this project to jurisdictional streams or wetlands. D. FEMA FLOODPLAIN There are FEMA mapped floodplains located on the site per FIRM Panel 3710947300J, effective date Oct. 17, 2006. See Appendix D for FEMA FIRM maps. No floodplains will be impacted by the development of the site E. SOILS Refer to Appendix C for the NRCS map showing anticipated on-site soils. II. AGENCY STORMWATER REQUIREMENTS A. Hoke County Section 3.7 `Storm Drainage Not in Public Streets" of the Hoke County Subdivision Ordinance details the requirements for managing stormwater from new construction sites. Section 3.3 `Streets" of the Hoke County Subdivision Ordinance details the requirements for managing stormwater from new construction sites per NCDOT requirements. Stormwater Impact Analysis-Carter Farms Subdivision Page 2 1 4 B. NCDEQ Hoke County is a `tipped' county and new projects located within the county must meet NCDEQ Post Construction Stormwater Phase 2 regulations. Site requirements for stormwater control are different if the proposed development is `high density' (greater than 24%impervious) or `low density' (less than 24%impervious). III. PROPOSED IMPROVEMENTS A. PROJECT DESCRIPTION The proposed project will create fifteen (15) single family lots (min 20,000 sf) in phase 1. The proposed project will add additional roads the Hoke County road system. The design follows the Preliminary Plat that was recently approved by Hoke County. As part of this project, public water will be extended to serve the new lots. B. LAND DISTURBANCE AND EROSION CONTROL The proposed disturbed area for the proposed project is 9.5 AC +/-. A NCDEQ Land Disturbance (Erosion Control) Permit will be obtained prior to beginningwork. C. IMPERVIOUS SURFACE The proposed total amount of impervious surfaces for this project is 7.68 AC. Phase 1 contains 2.39 ac of the total project impervious. This includes pavement and curb & gutters in the public R/W and driveways and rooftops on each lot. The resulting percent impervious (or built-upon) of 22.2% of the total project area. Phase 1 will result in a percent impervious of 13.0% of the total project area. A maximum amount of 4,738 SF of impervious area is allocated to each lot. Thus, this development is classified as `low density' under NCDEQ Phase II regulations. Stormwater Impact Analysis-Carter Farms Subdivision Page 3 1 4 D. DRAINAGE AND STORMWATER MANAGEMENT i. Roadway Drainage-Minor System The proposed roadway will have curb and gutter. Catch basins in the gutter line will provide the roadway drainage. Catch basins were spaced based on gutter spread not exceeding one-half lane width during a 4 in/hr storm (NCDOT guidelines). The minor pipe system is sized based on 10-year storm flow and cross-pipes are sized based on 25-year storm flow not exceeding the hydraulic capacity of each pipe segment (as open channel flow, that is, non- pressure flow). ii. Grass Conveyance Swales As stated in Section III. C. above, proposed impervious is less than 24% and, therefore is classified as `Low Density' per NCDEQ regulations. Per NCDEQ guidance, Grass swales are proposed to receive runoff collected by the catch basins in the road system to help treat the runoff before being discharged to the jurisdictional waters. The treatment swale has a longitudinal slope of 0.0%that discharge through a swale level spreader to the north. There is one proposed grass treatment swale (PC#1), that accounts for the runoff for swales #2 &3 (PC#2, PC#3).The proposed grass treatment swale has a length greater than 100 LF per post stormwater rules. A routing analysis of the swales was performed to account for infiltration of the soils and the available volume in the swales since the bottom elevation of the swale PC#1 is below the outlet elevation. The lower bottom elevation provides retention of the 25-yr storm which reduces the outflow through the level spreader by 15.2 CFS. The post development flow into swale PC#1 is 33.94 cfs (18.4 ac, I=calc.TC, c=0.40). The pre-development flow is 13.80 cfs (6.8 ac, I=calc. TC, c=0.30). The retention within the swale reduces the post- development flow to 14.54 CFS as compared to pre-development flow at 13.80 CFS (1 .34 CFS increase). In addition to the flow reduction the level spreader reduces the outlet velocity to 1.18 ft/s. iii. Methodology and computations Refer to Appendix A for storm drainage and stormwater management computations. Hydrologic computations were based on the Rational Method for storm drainage and SCS method for stormwater management. Rainfall intensity was determined based on data of the closest rainfall gauge listed on the NOAA website. Drainage areas were delineated based on a combination of field and LIDAR topography. Stormwater Impact Analysis-Carter Farms Subdivision Page 4 1 4 APPENDIX A Computations Minor System Grass Conveyance Swales Erosion Control Minor System Upstream Inlet Inlet Rainfall Pipe Capacity Gutter Gutter Gutter Drainage Area Pipe Diameter Total Pipe Flow Total System Pipe Slope Pipe Invert Pipe Invert Elevation(Top) Inlet Elevation Flow(Total Flow(Total Inlet ID Inlet ID Runoff (acres) Intensity*(in/h) (in) Pipe Material Pipe Length(ft) (Full Flow) (ft'/s)(1) Flow(ft'/s) (ft/ft) (Upstream)(ft) (Downstream)(ft) Inlet ID (ft)(3) (Invert)(ft) Inlet Type 4 iNhr Intercepted) Bypassed) Coeficient (5) (ft'/s) (ft'/s)(2) (ft'/s) (ft'/s) FES 104 CB 103 0.35 3.20 5.99 18 Class II I RCP 20.00 19.70 6.71 6.71 0.0300 199.63 199.03 FES 104 202.00 199.63 NCDOT 840.19 - - CB 103 CB 102 0.70 0.25 7.97 24 Class III RCP 24.00 17.32 1.39 8.10 0.0050 197.63 197.51 CB 103 202.53 197.63 NCDOT 840.03 0.82 0.47 CB 102 JB 101 0.70 0.20 7.97 24 Class III RCP 14.50 17.32 1.12 922 0.0050 197.51 197.41 CB 102 202.53 197.51 NCDOT 840.03 0.66 0.38 DI 101(6) FES 100 - - - 24 Class I II RCP 85.00 17.32 - 922 0.0050 197.42 197.00 DI 101(6) 202.40 197.42 NCDOT 840.19 - - - CB 206 CB 205 0.35 0.50 7.97 15 Class I II RCP 166.00 6.99 1.39 1.39 0.0102 206.36 204.66 CB 206 204.81 206.36 NCDOT 840.03 0.70 0.54 0.16 CB 205 CB 203 0.35 0.70 7.97 15 Class III RCP 348.00 6.99 1.95 3.35 0.0097 204.66 201.30 CB 205 204.81 204.66 NCDOT 840.03 1.14 0.81 0.33 FES 204 CB 203 0.35 2.10 8.89 15 Class III RCP 2000. 12.12 6.53 6.53 0.0300 201.94 201.34 FES 204 204.81 201.94 NCDOT 840.03 2.94 1.41 0.65 CB 203 CB 202 0.70 0.19 7.97 24 Class III RCP 24.00 21.91 1.06 10.94 0.0083 200.34 200.14 CB 203 204.81 200.34 NCDOT 840.03 0.86 0.48 0.12 CB 202 JB 201 0.70 0.40 7.97 24 Class III RCP 14.50 2035. 2.23 13.17 0.0069 200.14 200.04 CB 202 204.81 200.14 NCDOT 840.03 1.12 0.46 0.10 DI 201(6) FES 200 - - - 24 Class III RCP 85.00 2079. - 13.17 0.0072 200.04 199.43 DI 201(6) 205.01 200.04 NCDOT 840.19 - - - Notes 1 Storm System Sizing based on 10-yr Storm 2 Gutter Spread Calculations based on Storm Intensity of 4 inthr 3 CB(Catch Basin)Top Elevation is BOC 4 Gutter Spread Width is measured from Edge of Pavement 5 Storm System Sizing based on 25-yr Storm-for cross pipe drainage 6 Inlet is for secondary collection-No intial flow captured. Culvert Report Hydraflow Express Extension for AutoCADO Civil 3D0 2009 by Autodesk, Inc. Wednesday,Sep 21 2022 FES 104 Invert Elev Dn (ft) = 199.03 Calculations Pipe Length (ft) = 20.00 Qmin (cfs) = 6.71 Slope (%) = 3.00 Qmax (cfs) = 6.71 Invert Elev Up (ft) = 199.63 Tailwater Elev (ft) = Normal Rise (in) = 18.0 Shape = Cir Highlighted Span (in) = 18.0 Qtotal (cfs) = 6.71 No. Barrels = 1 Qpipe (cfs) = 6.71 n-Value = 0.012 Qovertop (cfs) = 0.00 Inlet Edge = Projecting Veloc Dn (ft/s) = 8.35 Coeff. K,M,c,Y k = 0.0045, 2, 0.0317, 0.69, 0.5 Veloc Up (ft/s) = 5.32 HGL Dn (ft) = 199.73 Embankment HGL Up (ft) = 200.64 Top Elevation (ft) = 202.50 Hw Elev (ft) = 201.14 Top Width (ft) = 18.00 Hw/D (ft) = 1.01 Crest Width (ft) = 10.00 Flow Regime = Inlet Control Elev(ft) FES 104 Hw Depth(ft) 203.00 3.37 202.00 2.37 201.00 net control 1.37 200.00 0.37 199.00 -0.63 198.00 L -1.63 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 Cir Culvert HGL Embank Reach(ft) Culvert Report Hydraflow Express Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. Wednesday,Sep 21 2022 FES 204 Invert Elev Dn (ft) = 201 .34 Calculations Pipe Length (ft) = 20.00 Q m i n (cfs) = 6.53 Slope (%) = 3.00 Qmax (cfs) = 6.53 Invert Elev Up (ft) = 201 .94 Tailwater Elev (ft) = Normal Rise (in) = 18.0 Shape = Cir Highlighted Span (in) = 18.0 Qtotal (cfs) = 6.53 No. Barrels = 1 Qpipe (cfs) = 6.53 n-Value = 0.012 Qovertop (cfs) = 0.00 Inlet Edge = Projecting Veloc Dn (ft/s) = 8.29 Coeff. K,M,c,Y,k = 0.0045, 2, 0.0317, 0.69, 0.5 Veloc Up (ft/s) = 5.26 HGL Dn (ft) = 202.03 Embankment HGL Up (ft) = 202.93 Top Elevation (ft) = 204.84 Hw Elev (ft) = 203.42 Top Width (ft) = 18.00 Hw/D (ft) = 0.99 Crest Width (ft) = 10.00 Flow Regime = Inlet Control Elev(ft) FES 204 Hw Depth(ft) 205.00 3.06 204.00 2.06 Inlet control 203.00 1.06 202.00 0.06 201.00 -0.94 200.00 -1.94 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 Cir Culvert HGL Embank Reach(ft) Grass Conveyance Swales Permanent Channel# 1 =>DA# PD 1 Calculate Flow-Rational Method 25-VrStorm Qzs=CIA C= 0.35 1= 5.92 in/hr CALCTc Qzs= 38.12 A= 18.40 ac Channel Slope= 0.00 Channel Depth=rndy 2.50 Channel Bottom Width= 4.00 Side Slopes= 3.00 Veloci = 2.31 Soil Type @loam Slopes=0-10% Channel Lining Shear Calculation T=yds y= 62.4 Ibs /ftz dw, Mft T= 0.58032lbs s= ft/ft Temporary=NAG S75BN Permanent=Fescue Permanent Channel# 2 =>DA# Calculate Flow-Rational Method 25-VrStorm Qzs=CIA C= 0.30 1= 8.89 in/hr Q25= 5.87 A= 2.20 ac Channel Slope= 1.60 Channel Depth= 2.50 Channel Bottom Width= 4.00 Side Slopes= 3.00 Velocity= 3.97 Soil Type @ sandy loam Slopes=0-10% Channel Lining Shear Calculation T=yds y= 62.4lbs dwater= 0.7 ft T= 0.69888 Ibs/ftz s= 0.02 ft/ft Temporary=NAG S75BN Permanent=Fescue Permanent Channel # 3 => DA# 204 Calculate Flow- Rational Method 25-Yr Storm Q25= CIA C= 0.35 1= 8.89 in/hr CA LC Tc Q25= 6.53 A= 2.10 ac Channel Slope= 1.00 Channel Depth= 1.00 Channel Bottom Width= 0.00 Side Slopes= 3.00 Velocity= 3.49 Soil Type @ sandy loam Slopes= 0-10% Channel Lining Shear Calculation T=yds y= 62.4lbs dwater 0.79 ft T= 0.24648 Ibs/ftZ s= 0.005 ft/ft Temporary= NAG S75BN Permanent= Fescue U.S. Department of Agriculture FL-ENG-21 B Natural Resources Conservation Service 06/04 TR 55 Worksheet 3: Time of Concentration (Tc) or Travel Time (Tt) Project: Carter Farms Subdivison Designed By: MTB Date: Location: Hoke County, NC Checked By: MDA Date: Check one: y/ Present Developed Check one: V T, Tt through subarea DA#104 NOTES: Space for as many as two segments per flow type can be used for each worksheet. Include a map, schematic, or description of flow segments. Sheet Flow (Applicable to T, only) Segment ID 1 1. Surface description (Table 3-1) ................................................ GRASS 2. Manning's roughness coeff., n (Table 3-1) .............................. 0.04 3. Flow length, L (total L < 100 ft) .............................................. ft 100 4. Two-year 24-hour rainfall, P2.................................................. in 0.1 5. Land slope, s ....................................................................... ft/ft 0.050 6. Tt =0.007 (nL)0.8 Compute Tt.......................... hr 0.18 + = 0.18 P2 0.5 S0.4 Shallow Concetrated Flow Segment ID 2 7. Surface description (paved or unpaved) ................................... UNPAVED 8. Flow length, L ......................................................................... ft 557 9. Watercourse slope, s ........................................................... ft/ft 0.013 10. Average velocity, V(Figure 3-1) .......................................... ft/s 1.9 11. Tt = L Compute Tt ......................... hr 0.08 + 3600 V Channel Flow Segment ID 12. Cross sectional flow area, a ............................................... ft2 0.0 13. Wetted perimeter, PW ......................................................... ft 0.0 14. Hydraulic radius, r= a Compute r .................................. ft PW 15. Channel Slope, s ............................................................ ft/ft 0.000 16. Manning's Roughness Coeff., n ............................................ 0.00 17. V= 1.49 r2/3 s'/2 Compute V ...................... ft/s 0.0 n 18. Flow length, L ...................................................................... ft 0 19. Tt = L Compute Tt.................................... hr + _ 3600 V 20. Watershed or subarea Tc or Tt (add Tt in steps 6, 11, and 19 ................................................................. hr 0.26 0.26= 15.6 mins Chapter 3 Time of Concentration and Travel Time Technical Release 55 Urban Hydrology for Small Watersheds Figure 3-1 Average velocities for estimating travel time for shallow-concentrated flow .50 .20 .10 i2 d a. a h .06 m 0 a M .04 �-I a 02 .01 .005 1 2 4 6 10 20 1.9 Average velocity(ftlsec) 3-2 (210-V1-TR-55,Second Ed.,dune 1986) LEVEL SPREADER# 1 Calculate Flow- Rational Method 0.75 in/hr Design Storm Q= CIA C= 0.40 1= 0.75 in/hr per MDC Q= 3.00 A= 10.00 ac Required Level Spreader L= 10 feet/1 cfs Required Level Spreader L= 30.00 ft Proposed Spreader L= 55.00 ft Flow Depth 0.00 Flow discharged via inflitration in swale 10-Yr Storm Q10= Outflow Treatment swale Q10= 0.74 cfs Flow Depth= 0.03 cfs Proposed Stone Spreader Dims Spreader L= 55 ft Apron Width= 6 ft Stone D= 12 in Stone Dia= Class A e POI#01 Pre Developmemt SCM01 SCM 1 DA 01P SCM #01 Subcat Reach on Link Routing Diagram for PC01 Prepared by Toshiba, Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Carter Farm Subdivision PC01 Type/1 24-hr 10-Year Rainfall=5.52" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment Pre POI #01: P0I#01 Pre Developmemt Runoff = 2.96 cfs @ 12.02 hrs, Volume= 0.489 af, Depth= 0.32" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.52" Area (ac) CN Description 0.000 39 Woods 18.400 39 Grass 0.000 90 Pavement 0.000 90 Sidewalk 0.080 90 Buidling 18.480 39 Weighted Average 18.480 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Pre POI #01: P0I#01 Pre Developmemt Hydrograph ■Runoff 2.96cfs - - - - - - - - - - - - - - - - - - - - - - 3 Type III 24-hr 10-Yuar Rainfall'=5.52 RUnioffArdcl,18.480 Ac 2 tAnQ Qrl�•T•Y�0r� -� w Runoff Qel'lpth=0.8�11 '--'�--'�--'�-- 1 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Carter Farm Subdivision PC01 Type/1 24-hr 10-Year Rainfall=5.52" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment SCM01: SCM 01 DA Runoff = 16.66 cfs @ 11.99 hrs, Volume= 1.035 af, Depth= 0.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.52" Area (ac) CN Description 2.390 90 Impervious 16.010 39 Pervious 18.400 46 Weighted Average 18.400 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment SCM01: SCM 01 DA Hydrograph + t t t ■Runoff 18 --I- 16.66 cfs -�-J-A-1-1-+-+-L-L-L- ----------J-J- -1-1-1-1-L- -L- -- 17 -------- ----'--'- -+-+-+-+-+- ---------------'--'- ------- - -fir- 16 _ I_ + + + + r _ _i 15 ------'--' --'--'-------------------------71J�i�� 14 I I I I I I I 12 -r---I--I --- - - -+-+-+-r-r-r-+-r-� r Off OM I' II--II--II--II--I -----1-1-+-+-+-r-r-r-r-r---I--I--I--I-7-r-,-7-7-7-}+-r-r-r-r-I-- 10 0 9 -+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+ -��* �, LL 8 +-+-+--- I�TJ� �111-- 7 -------- ----- - -+-+-+-+-+- - - ---------- - - - - - -+-CN - 6 L-----'-- --'-J-J-L-1-+-+-+-L-r-L-L-L--------J-J-L- -1-1-1-r-L-L-L-I- 5 4 3 2 -------- ---- - - - - - - ------------------ - - - - - - ------- 1 I I I I I I I I I I I I I I I I I I I I I I I I I I 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Carter Farm Subdivision PC01 Type/1 24-hr 10-Year Rainfall=5.52" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 4 Summary for Pond 01 P: SCM #01 Inflow Area = 18.400 ac, 0.00% Impervious, Inflow Depth = 0.67" for 10-Year event Inflow = 16.66 cfs @ 11.99 hrs, Volume= 1.035 of Outflow = 1.43 cfs @ 13.95 hrs, Volume= 1.034 af, Atten= 91%, Lag= 117.5 min Primary = 0.47 cfs @ 13.95 hrs, Volume= 0.894 of Secondary = 0.96 cfs @ 13.95 hrs, Volume= 0.140 of Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Starting Elev= 197.00' Surf.Area= 3,765 sf Storage= 2,259 cf Peak Elev= 199.03' @ 13.95 hrs Surf.Area= 15,748 sf Storage= 21,549 cf (19,290 cf above start) Plug-Flow detention time= 591.6 min calculated for 0.983 of(95% of inflow) Center-of-Mass det. time= 530.0 min ( 1,451.4 - 921.4 ) Volume Invert Avail.Storage Storage Description #1 194.00' 21,549 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) 194.00 3,765 0.0 0 0 195.00 3,765 20.0 753 753 196.00 3,765 20.0 753 1,506 197.00 3,765 20.0 753 2,259 198.00 9,533 100.0 6,649 8,908 199.00 15,748 100.0 12,641 21,549 Device Routing Invert Outlet Devices #1 Primary 197.00' 1.500 in/hr Exfiltration over Surface area above 197.00' Conductivity to Groundwater Elevation = 190.00' Excluded Surface area = 3,765 sf #2 Secondary 199.00' 55.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=0.47 cfs @ 13.95 hrs HW=199.03' (Free Discharge) L1=Exfiltration ( Controls 0.47 cfs) Secondary OutFlow Max=0.74 cfs @ 13.95 hrs HW=199.03' (Free Discharge) L2=Broad-Crested Rectangular Weir(Weir Controls 0.74 cfs @ 0.44 fps) Carter Farm Subdivision PC01 Type/1 24-hr 10-Year Rainfall=5.52" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 5 Pond 01 P: SCM #01 Hydrograph 16.66 CfS - ■Inflow -r-r--r-r-rr-+-r--r-r--r-+-r--r-r--r-r-r--r-r- ■outflow ------ --------------------- �� ��{{" /�A r- ■Primary h1fl "= 10.4004 ■Secondary 18 17 16 � � "'�J 14 -I-+-F -T- --+-T--T-r- T-+-T-I- -r--7-+- -I- -r-I- -T- -I- -r13 12 11 1-1-L -L-'--'-+-L_I_1-L_I_J-1-L_I_ - - w i 10 ---Y-r -r-I--I-Y-r-I-r-r-I-r-+-r-I-r-r--r-+-I---r-r-I-r-r----�-r- 3 9 lO 8 --I-+_T -T-�--+-T--+-T- -T-T--,-r-I-�-T-�-I-,-r----T-�---_r_ 7 --i-i-i -i-i-i-i-i--i-i-i-i-i-i-- - ---i-i-i-- - ---i-i-i--i-i- ------------------------------------------------ 5 -+ - ++ -+-+-1-+-+--+-+-++-+-+-++-+-++-+-+-++-+-+--+-+- 1.43 cfs 3 2 0.96 cfs 1 0 2 4 6 8 1012 14 1618 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Carter Farm Subdivision PC01 Type 11 24-hr 25-Year Rainfall=6.67" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment Pre POI #01: P0I#01 Pre Developmemt Runoff = 13.80 cfs @ 12.00 hrs, Volume= 1.007 af, Depth= 0.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Year Rainfall=6.67" Area (ac) CN Description 0.000 39 Woods 18.400 39 Grass 0.000 90 Pavement 0.000 90 Sidewalk 0.080 90 Buidling 18.480 39 Weighted Average 18.480 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Pre POI #01: P0I#01 Pre Developmemt Hydrograph r-r-i--i--i--i--i--i-y-y-t-t-+-t-r-r-r-r-r-r-i--i--i-y-y-y-�-rt-rt-t-r-r-r-r-r 15 1 ■Runoff 13.80cfs - - - - - - - - - - - - - - - - - - 14 r-r---i--i -----y-y-t-t-+-t-r-r-r-r-r-r------y-y-y T 13 ------ ---- 12 - 25-Yearl Rain 11=6.IV/ "-- r-r-i--i--i --i--i-y-y-t-t-+-t-r-r-r-r-r-r-i--i--i-y-y-y-�-rt-rt-t-r-r-r-r-r- 10 npff OM 9 Iu Hoff Deph= fi5 0 7 T -------- -----------------------------------------Jd: 5.0-tnin 6 -------- ----- - - - - - - - - - ---------- - - - - - - -��� - 5 -----i- - -r-r-r-i-i---------------i-i-i-i- - -i-i-i 4 3 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Carter Farm Subdivision PC01 Type 11 24-hr 25-Year Rainfall=6.67" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment SCM01: SCM 01 DA Runoff = 33.74 cfs @ 11.98 hrs, Volume= 1.783 af, Depth= 1.16" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Year Rainfall=6.67" Area (ac) CN Description 2.390 90 Impervious 16.010 39 Pervious 18.400 46 Weighted Average 18.400 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment SCM01: SCM 01 DA Hydrograph ------------------------------------------ ■Runoff 36 --- 33.74 I'1-I'1--I', -pI', - 34 1 IT R"�OZ4-hr- ----r-r-r-T-r-r-r-r-r-r-i-i------r-r-r-r 32 r-----i--i Y p c7 ai 28 r-r---i--i -----t-t-t-t-r-r-r-r-r-r-r-r ---t - r r- 26 FZwrio'ff /ark& 19.400 dG r-r---i-- - ----t-t-t-t-r-r-r-r-r-r-r-I- i---i-.p--r-y-y-u4r rt-rtpp-t-r�r-r-r-r- 24 ff V101 y 2220 -------- -----+-+-+-+-+-+-+-+-+-+----------+-+-+-+-+-+-+-+-+-+-+��- p���^�{c 18 --'--'--'-- ----'-J- -1-L- -L-L-L-L-L----------J-J- - _1TC JO- 1n-- ML T 16 ------'-- --'--'- - -i-1-i-L-L-L- -+-------'--'- - - -1-1-1-i-L-r- -+-'-- 14 j------'-- ------'- -'-'-'-'-'-'---------------'--'-'-'- 12 10 8 6 4 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Carter Farm Subdivision PC01 Type 11 24-hr 25-Year Rainfall=6.67" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 8 Summary for Pond 01 P: SCM #01 Inflow Area = 18.400 ac, 0.00% Impervious, Inflow Depth = 1.16" for 25-Year event Inflow = 33.74 cfs @ 11.98 hrs, Volume= 1.783 of Outflow = 15.52 cfs @ 12.10 hrs, Volume= 1.783 af, Atten= 54%, Lag= 7.3 min Primary = 0.48 cfs @ 12.10 hrs, Volume= 0.914 of Secondary = 15.03 cfs @ 12.10 hrs, Volume= 0.869 of Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Starting Elev= 197.00' Surf.Area= 3,765 sf Storage= 2,259 cf Peak Elev= 199.23' @ 12.11 hrs Surf.Area= 15,748 sf Storage= 21,549 cf (19,290 cf above start) Plug-Flow detention time= 345.0 min calculated for 1.730 of(97% of inflow) Center-of-Mass det. time= 316.1 min ( 1,213.0 - 896.8 ) Volume Invert Avail.Storage Storage Description #1 194.00' 21,549 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) 194.00 3,765 0.0 0 0 195.00 3,765 20.0 753 753 196.00 3,765 20.0 753 1,506 197.00 3,765 20.0 753 2,259 198.00 9,533 100.0 6,649 8,908 199.00 15,748 100.0 12,641 21,549 Device Routing Invert Outlet Devices #1 Primary 197.00' 1.500 in/hr Exfiltration over Surface area above 197.00' Conductivity to Groundwater Elevation = 190.00' Excluded Surface area = 3,765 sf #2 Secondary 199.00' 55.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=0.48 cfs @ 12.10 hrs HW=199.23' (Free Discharge) L1=Exfiltration ( Controls 0.48 cfs) Secondary OutFlow Max=14.54 cfs @ 12.10 hrs HW=199.22' (Free Discharge) L2=Broad-Crested Rectangular Weir(Weir Controls 14.54 cfs @ 1.18 fps) Carter Farm Subdivision PC01 Type 1124-hr 25-Year Rainfall=6.67" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 9 Pond 01 P: SCM #01 Hydrograph 33.74 CfS - - - ■inflow - - -- - -- - - -- - -- - ---- - -- - ---- - - ■Outflow ■Primary 11i1V W /�1�i�� Iiv��l7V ��ii ■Secondary ---+-r -r----+-r--T-r--r-T-r--r-r--r-T----r-r--r-T----�-r- 36 �, 34 __� _� _ P'e' ev-1 -23 - 32 �p = 30 "'.7 e 28 26 --i-r-r -r-r-i-r-r-i-r-r-rr-+-r-i-r-r-i-r-+-r-i-r-r-i-r-r-r-i-r-r- 24 i 1 w 22 15.52 Cfs '�J- - -- - -��--�-�- zo 3 1$ 0 16 15103 CfS -r-r--r-r--r-r-rr-+-r--r-r--r-+-r--r-r--r-r-r--r-r- 14 -r-i -r- 12 - ---- - -- - -- - - -- - -- - ---- - -- - ---- - - 10 8 6 4 2 0 2 4 6 8 1012 14 1618 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Carter Farm Subdivision PC01 Type/1 24-hr 100-Year Rainfall=8.60" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment Pre POI #01: POI#01 Pre Developmemt Runoff = 40.53 cfs @ 11.98 hrs, Volume= 2.184 af, Depth= 1.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=8.60" Area (ac) CN Description 0.000 39 Woods 18.400 39 Grass 0.000 90 Pavement 0.000 90 Sidewalk 0.080 90 Buidling 18.480 39 Weighted Average 18.480 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment Pre POI #01: POI#01 Pre Developmemt Hydrograph -7 7 7 -1--1--1--1-+-+-t-+-+-+-r-r-r-r-r-r-1--1--1-+-+-+-+-+-+-+-r-r-r-r-r- 44 --i 42 ■Runoff 40.53 cfs -'- '- - - - - - - - - ----------�'-�'- - - - - - - - - -�'-- I I Tye �4-6-r - 40 -------- ----- - -+-+- -r-r-r- - ---------- - - - 1 1 1 1 1 I I I I I I I I I I I I I I I I I I I I I 38 r-r-1--1--1 --1--1-t-r-t-t-t-r-r-r-r-r-r-rA-/--/1--I�-/r-ry-rprwrt-1-t-r-rp-rc-nr-I-- 36 34 ------'--' ----'-L- -L-L-L-L-L-L-L-r-'--'--'p-----L-L-L-1y�-,1�-1A-10-Lw-r-/fir-r-'-- 32 ------i-- ----1-+-+-+-+-+-+-+-+-+-+---1-i� � i��i`iQ�1ET. F�it �-- 30 m1 1 nI �I� I7-- AI -----r-r-T-T-r-r-r-r_r_r-I - rlr� -ff ��f�4�'�rY��'.i_84 28 ------'-- ----'--'- - - - - - - -�-'--' of - w26 ------�-- -----r- - - - -r-r-r- - --------p-r- - - -'- - -r-r-�- -1-- 2 24 r-1--r-1-- --1--1-r-T-T-T-r-r-r-r-r-r-r-r-1--1- 1 t#ii FF 1"r 3 22 -- --(1��---^�T--- ym-�-G-- l0 20 i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 18 --1--1--1-- --1--1-+-+-+-+-+-+-+-r-r-+-1--1--1--1--1-+-+-+-+-+-+-+- r- 16 ------�1-- --- - - -T-T-r-r-r-r-r-�r-��-��------ - - - -7-7-T- � - 14 ------'-- ------'- -'-'-'-'-'-'-'-----------'--'-'-'-'- -'-'-'-'-'---'-- 12 --1--1--i-- --i--1- - - - - -r-r-r- - -------i--1- - - - - - - -r-r- - -i-- 10 --1--1--1-- -----T-r-T-T-r-r-r-r-r-r----------T-r-r- -r-T-T-r-r-r-r-I-- 6 -------- ----L- -L-L-L-L-L-L- - ----------L- - -L-L-L-L-L-L- - --- 4 r-r-1--1-- --+-+-+-+-+-+-r-r-r-r-r-r-1--1--1-+-+-+-+-+-+-+-r-r-r-r-r- 2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Carter Farm Subdivision PC01 Type/1 24-hr 100-Year Rainfall=8.60" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment SCM01: SCM 01 DA Runoff = 68.81 cfs @ 11.97 hrs, Volume= 3.331 af, Depth= 2.17" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=8.60" Area (ac) CN Description 2.390 90 Impervious 16.010 39 Pervious 18.400 46 Weighted Average 18.400 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment SCM01: SCM 01 DA Hydrograph - --------------,-r-+-+-r-r-r-r-r-r-r-I--I--I--I-r-r-r- -r-T-+-r-r-r-r-I-- 75 ■Runoff -I-r- - - -----,-,-1+--1r--Lr--Lr--Lr--Lr--Lr--1r-r-r-------------T- I-1-1I -L-L- -L 70 68.8 1 L P-p- - - =� - 65 60 -' -' -' -' -''f0�f-Year Rain�f 11=8.60'�- 55 ----Ruhoff Arn&�1&400 jAc-- -- 50 I N�® � +-+-+-i-- -+-+-+-+-+-+-+-+-+-r-+-+-+ npff •T•Y w 45 w ---- 40 Runoff Depth=Z'�' =- LL 35 30 +-+-+ -- -+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-CN=40- 20 15 10 tttt 0 L H....6....I....I....I....I....I....1. 1....I.... I....I....I....I....I....I....I....I....I........2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Carter Farm Subdivision PC01 Type/1 24-hr 100-Year Rainfall=8.60" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 12 Summary for Pond 01 P: SCM #01 Inflow Area = 18.400 ac, 0.00% Impervious, Inflow Depth = 2.17" for 100-Year event Inflow = 68.81 cfs @ 11.97 hrs, Volume= 3.331 of Outflow = 81.44 cfs @ 11.99 hrs, Volume= 3.331 af, Atten= 0%, Lag= 1.3 min Primary = 0.50 cfs @ 11.99 hrs, Volume= 0.921 of Secondary = 80.94 cfs @ 11.99 hrs, Volume= 2.410 of Routing by Stor-Ind method, Time Span= 1.00-72.00 hrs, dt= 0.05 hrs Starting Elev= 197.00' Surf.Area= 3,765 sf Storage= 2,259 cf Peak Elev= 199.67' @ 11.99 hrs Surf.Area= 15,748 sf Storage= 21,549 cf (19,290 cf above start) Plug-Flow detention time= 184.6 min calculated for 3.279 of(98% of inflow) Center-of-Mass det. time= 170.3 min ( 1,043.4 - 873.2 ) Volume Invert Avail.Storage Storage Description #1 194.00' 21,549 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic-feet) (cubic-feet) 194.00 3,765 0.0 0 0 195.00 3,765 20.0 753 753 196.00 3,765 20.0 753 1,506 197.00 3,765 20.0 753 2,259 198.00 9,533 100.0 6,649 8,908 199.00 15,748 100.0 12,641 21,549 Device Routing Invert Outlet Devices #1 Primary 197.00' 1.500 in/hr Exfiltration over Surface area above 197.00' Conductivity to Groundwater Elevation = 190.00' Excluded Surface area = 3,765 sf #2 Secondary 199.00' 55.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=0.50 cfs @ 11.99 hrs HW=199.63' (Free Discharge) L1=Exfiltration ( Controls 0.50 cfs) Secondary OutFlow Max=74.67 cfs @ 11.99 hrs HW=199.63' (Free Discharge) L2=Broad-crested Rectangular Weir(Weir Controls 74.67 cfs @ 2.15 fps) Carter Farm Subdivision PC01 Type/1 24-hr 100-Year Rainfall=8.60" Prepared by Toshiba Printed 9/21/2022 HydroCADO 10.00-20 s/n 07811 ©2017 HydroCAD Software Solutions LLC Page 13 Pond 01 P: SCM #01 Hydrograph --1-1-L-1-1-1-1--1-1-L-1-1-L-1-J-1-L-i-�-�-�-J-+-�--�-�-L-1-J-1-1--1-1-L- -+-+-++-+-+-++-+-++-+-+-++-+-++-+-+-++-+-++-+-+-++-+-++-+-+- ■Inflow +--+-+-+--+-+--+-+-+--+-+--+-+-+--+-+--+-+-+--+-+- ■outflow � � - �p� /�� � ■Primary 90 r-r--7-r-I- -r-r�-T-r-�� �rJYY i�W�����Eh �it��Fir- ■Secondary 85 80.94 cfs cfs T- -T-T T-T- -T- -+ - ,T- 80 - ---------------------------PekT;F� v-� �.� - 75L 70 - 65 60 55 u 50 3 45 LL 40 -1-1--1-i-L--1-L--J-1-L-'- -L--J-1-'--'- -L-'- -i----1-L- 35 30 -1-1--1-i-L-'-1-L-'-J-L-L-'-�-L-'-J-L-'--'-�-L-'-J-i-'--'-�-L- 25 20 15 10 S 5 0 2 4 6 8 1012 14 1618 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Erosion Control Sediment Basin# 1 Calculate Flow- Rational Method 10-Yr Storm 25-Yr Storm Q10=CIA C= 0.30 Q25 = CIA C= 0.30 1= 7.98 1= 8.89 Q10= 30.88 A= 12.90 Q25 = 34.40 A= 12.90 2-Yr Storm Q2= CIA C= 0.30 1= 6.18 Q2 = 23.92 A= 12.90 Calculate Required Surface Area SA=Q10 x 435 sf/cfs Q10= 30.88 SA= 13433.93 ft2 Side Slopes= 3.00 :1 Pond Depth= 4.00 ft Basin Dims (Per SA) Top= 79.00 x 213.00 = 16827 ft2 Weir= 67.00 x 201.00 = 13467 ft2 Bottom = 43.00 x 177.00 = 7611 ft2 Volume Required VR=Ax1800 cf/ac A= 12.90 ac VR= 23220.00 ft3 Volume Proposed VP=((Top Area + Bottom Area)/2)xD Top= 16827.00 sf Bottom= 7611.00 sf VP= 48876.00 ft3 D= 4.00 ft Skimmer Sizing Calculate Dewater Time Qd=V/Td V= 23220.00 ft 3 Td= 5 3-5 days typ Qd= 4644.00 cf/day Calculate Orifice Diameter D=sgrt((Qd/(2310sgrt(h))) Qd= 4644.00 h= 0.33 D= 1.87 Use 4 " Skimmer w/ 1.87 " Orifice Principle Spillway Sizing L=Q2/(cH1.5) L= ? ft H= 1.50 ft c= 3.10 L= 4.20 ft Riser Sizing C=pi X D C= 4.20 ft pi= 3.14 D= 16.05 i n D= ? ft Material= CMP Use 24.00 "CMP Riser Barrel Sizing Q2= CA X sgrt(2gh) C= 0.60 A= ? sf A= 2.12 Q2= 23.92 cfs h= 5.50 ft A=pi X r2 g= 32.20 ft/s A= 19.71 in Material= CMP Use 18.00 "CMP Barrel Size Riser/Barrel Base Calculate Bouyance Force on Riser Cross-sectional area A=(pi x r2)x 2 r= 1.00 A= 6.28 sf Riser Volume V=A x L A= 6.28 L= 4.00 V= 25.12 Bouyance Force FB=qV q= 62.40lbs V= 25.12 ft3 FB= 1567.49lbs/cf Concrete Base Sizing (Concrete = 120 Ibs/cf)-(weight of water= 62.4 Ibs/cf) =57.6 Ibs/cf x 1.1 SAFETY FACTOR Base Volume 29.93 cf Base Dims= 5.47 ft x 5.47 ft x 1.00 ft Weir Sizing Per AutoCa d Hyd raflow Software L= 10.00 ft D= 2.00 ft dwater 1.00 ft Q25= 34.40 cfs Velocity= 3.37 ft/s Weir Lining Shear Calculation T=yds y= 62.4 Ibs dwater 1 ft T= 0.624 Ibs/ft2 s= 0.01 ft/ft Required Liner= Class A Rip Rap Proposed Liner= Class A Rip Rap Temporary Diversion/Berm# 1 =>DA# EC401 Calculate Flow-Rational Method 25-Yr Storm Q25=CIA C= 0.40 I*= 5.92 in/hr *IntensityperTc Q25= 23.68 A= 10.00 ac Channel Slope= 0.20 Channel Depth= 2.50 Bottom Width= 4.00 Side Slopes= 3.00 Velocity-- 3.42 Soil Type @ Loamy Sand Slopes=0-10% Channel Linin¢ Shear Calculation T=yds y= 62.4lbs cl_,= 1.3 ft T= 0.4056 Ibs/ft2 s= 0.005 ft/ft Temporary= NAG S75BN Permanent= NAG S75BN Temporary Diversion/Berm# 2 =>DA# EC402 Calculate Flow-Rational Method 25-Yr Storm Q25=CIA C= 0.40 I*= 6.38in/hr *Intensity per Tc Q25= 4.59 A= 1.80 ac Channel Slope= 0.00 Channel Depth= 2.00 Bottom Width= 4.00 Side Slopes= 3.00 Velocity-- 1.40 Soil Type @ Loamy Sand Slopes=0-10% Channel Linin¢ Shear Calculation T=yds y= 62.4lbs cl—te,= 1.05 ft T= 0.3276 Ibs/ft2 s= 0.005 ft/ft Temporary= NAG S75BN Permanent= NAG S75BN Barrel Outlet Protection#1 New York Method 8.06.5 Manual Diameter of Barrel = 18.00 " La= 8 ft Velocity= 5.5 ft/s W= 6 ft Zone= 1 Stone Diameter= Class a Stone d= 12 in Outlet Protection#100 New York Method 8.06.5 Manual Q= 16.74 cfs La= 16 FT Pipe Diameter 24 in W= 6 FT Velocity= 17.3 ft/s d= 24 IN Zone= 3 Stone Diameter= Class I Outlet Protection#200 New York Method 8.06.5 Manual Q= 5.3 cfs La= 6 FT Pipe Diameter 15 in W= 4.5 FT Velocity= 4.9 ft/s d= 12 IN Zone= 1 Stone Diameter= Class A APPENDIX B Drainage Area Maps i � 1 \ � \ I � 210 � � � 1 I DA PDyI \ , I (ALL OTHER ORAINXG�AREAS INCLUDED) 18.4 AC r/— \ i --- J DA CBd202 0.4 AC r/— POd2 o 2. , 2.2 AC+�— I / / _ DA C81206 DA CBd201 0.6 AC+ 0.2 AC r/- -—— _ 0.7 AC r/— DA CBd203 ---- 0.2 AC+/— -- _ DA CBg103 / DA FESd204 / 0.25 AC+/— --._----- 2.111 AC+/— / �pW N.ANDERS DA DI®104 O / (PRlygTE) 5` ;WW----3-2 AC+/---- Averette Engineering Co.,P.A. sEA� -IN eY: REVISIONS SCALE MCK Na. DESCRIPTION DATE CARTER FARMS SUBDIVISION-PHASE 1 CHECKED BY: L Sv EEenvc 71.2Add E. C. D. AVERETTE CARTER ROAD 1" = 100' LAND SURVEYING 712 E.Lake Ritlge ROOtl PLANN/RG Raef.,d,NC 28376 PROJECT d: HOKE COUNTY,NORTH CAROLINA PN<ne:(910)488-5656 2020-11 SHEET NO.: Fax:(910)488-0181 — NAN License:C-0146 CPRTERFPRMS D&D DA2 DATE: DRAINAGE AREA MAP-INLET/PERMANENT CHANNELS Established 1970 Web:www.averette—eng—T 1, 5/18/2022 \ 210 DA 138#1 1 \ 7--- DA EC/401ID.D AC / Averette Engineering Co.,P.A. ckL' Dom+�' REVISIONS MTB ND. DESCRIPTION DATE CHECKED Bf: CARTER FARMS SUBDIVISION L 'v En envc 71.2Add E. C. D. AVERETTE CARTER ROAD 1'- 100 LAND SURVEYING 712 E.Lake Ritlge ROotl PLANK/NG Raef.,d,NC 28376 PROJECT/: HOKE COUNTY,NORTH CAROLINA PNane:(910)488-5656 2020-11 SHEET NO.: Fax:(910)488-0181 License:C-0146 CMfERFORMS DJ D DATE- DRAINAGE AREA MAP-EC DA1 Established 1970 Web:www.overette—eng.c2T 1, 5/18/2022 APPENDIX C Soil Survey Map Soil Map—Hoke County, North Carolina in v 674700 674800 674900 675000 675100 675200 675300 675400 675500 675600 34o 56'16"N I __ ---I 3 34o 56'16"N r ".. 7. NJ oA JT BaD GdB Oo� :' * 4 VIF Soil Map may not he valiel at this scale. 340 55'54"N - I - _ ti I 340 55'54"N 674700 674800 674900 675000 675100 675200 675300 675400 675500 675600 Map Scale:1:4,640 if printed on A landscape(11"x 8.5")sheet. a Meters N 0 50 100 200 300 Feet 0 200 400 800 1200 Map projection:Web Mercator Conermordinates:WGS84 Edge tics:UTM Zone 17N WGS84 usoA Natural Resources Web Soil Survey 7/21/2021 Conservation Service National Cooperative Soil Survey Page 1 of 3 Soil Map—Hoke County, North Carolina MAP LEGEND MAP INFORMATION Area of Interest(A01) Spoil Area The soil surveys that comprise your AOI were mapped at 0 Area of Interest(AOI) Stony Spot 1:24,000. p� Y Soils Very Stony Spot Warning:Soil Map may not be valid at this scale. 0 Soil Map Unit Polygons Wet spot Enlargement of maps beyond the scale of mapping can cause ,P Soil Map Unit Lines misunderstanding of the detail of mapping and accuracy of soil Other line placement.The maps do not show the small areas of Soil Map Unit Points Special Line Features contrasting soils that could have been shown at a more detailed M� Special Point Features scale. Blowout Water Features Streams and Canals Please rely on the bar scale on each map sheet for map Borrow Pit measurements. Transportation Clay Spot _ Rails Source of Map: Natural Resources Conservation Service Closed Depression Web Soil Survey URL: .,o Interstate Highways Coordinate System: Web Mercator(EPSG:3857) Gravel Pit US Routes Maps from the Web Soil Survey are based on the Web Mercator Gravelly Spot Major Roads projection,which preserves direction and shape but distorts distance and area.A projection that preserves area,such as the 0 Landfill Local Roads Albers equal-area conic projection,should be used if more A. Lava Flow Background accurate calculations of distance or area are required. Marsh or swamp Aerial Photography This product is generated from the USDA-NRCS certified data as of the version date(s)listed below. Mine or Quarry Soil Survey Area: Hoke County, North Carolina Miscellaneous water Survey Area Data: Version 17,Jun 4,2020 Perennial Water Soil map units are labeled(as space allows)for map scales Rock Outcrop 1:50,000 or larger. Saline Spot Date(s)aerial images were photographed: Jun 15,2015—Dec 4, 2017 Sandy Spot ° The orthophoto or other base map on which the soil lines were Severely Eroded Spot compiled and digitized probably differs from the background imagery displayed on these maps.As a result,some minor Sinkhole shifting of map unit boundaries may be evident. Slide or Slip o Sodic Spot usoA Natural Resources Web Soil Survey 7/21/2021 Conservation Service National Cooperative Soil Survey Page 2 of 3 Soil Map—Hoke County, North Carolina Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI BaD Blaney loamy sand,8 to 15 14.4 13.1% percent slopes CaB Candor sand, 1 to 8 percent 0.6 0.6% slopes GdB Gilead loamy sand,2 to 8 2.6 2.4% percent slopes GoA Goldsboro loamy sand,0 to 2 8.4 7.6% percent slopes, Southern Coastal Plain JT Johnston loam 10.2 9.3% LaB Lakeland sand, 1 to 8 percent 9.8 8.9% slopes NoA Norfolk loamy sand,0 to 2 20.0 18.2% percent slopes WaB Wagram loamy sand,0 to 6 43.8 39.9% percent slopes Totals for Area of Interest 109.7 100.0% USDA Natural Resources Web Soil Survey 7/21/2021 Conservation Service National Cooperative Soil Survey Page 3 of 3 APPENDIX D FEMA Firm Map �;- _.` --a � �' Fes• a`�, ure � ?�� ��r I I COO' • D lI2EAS, j. .L� ■y�'R J- �' �• �''' 4 ;N�+�* Creek J e m 34°56'30"N 4i, a o� F p - 1 S •� � � SITE r `` a i���A u 1 �� ► 4 h s �r r.�► a � 34°5601N a 1 79°5'30"W 79°5'0"W 79°4'30^W 1980000 FEET APPENDIX E USGS MAP \- - �- z - \ \ � SITE { / ) �\ ) / Q � - � � APPENDIX F STORMWATER FORMS SUPPLEMENT-EZ OPERATION & MAINTENANCE AGGREEMENT BMP SUPPLEMENT FORMS SUPPLEMENT-EZ COVER PAGE ORMS LOADI PROJECT INFORMATION 1 Project Name Carter Farms Subdivision-Phase 1 2 Project Area ac 10 3 Coastal Wetland Area ac 4 Surface Water Area ac 0 5 Is this project High or Low Density? Low 6 Does this project use an off-site SCM? COMPLIANCE WITH 02H.1003(4) 7 Width of vegetated setbacks provided feet 30 8 Will the vegetated setback remain vegetated? Yes 9 If BUA is proposed in the setback,does it meet NCAC 02H.1003 4 c-d? Yes 10 1 Is streambank stabilization proposed on this project? No NUMBER AND TYPE OF SCMs: 11 Infiltration S stem 0 12 Bioretention Cell 0 13 Wet Pond 0 14 Stormwater Wetland 0 15 Permeable Pavement 0 16 Sand Filter 0 17 Rainwater Harvesting RWH 0 18 Green Roof 0 Level Spreader-Filter Stri LS-FS 0 r2322 Disconnected Impervious Surface DIS 0 Treatment Swale 1 D Pond 0 StormFilter 0 24 Silva Cell 0 25 Ba filter 0 26 IFilterra 0 FORMS LOADED DESIGNER CERTIFICATION 27 Name and Title: Mike D.Averette PE 28 Or anization: Averette Engineering Co.,P.A. 29 Street address: 712 E.Lake Ridge Road 30 City,State,Zip: Raeford,NC 28376 31 Phone numbers : 910 488-5656 32 Email: Mike@averette-eng.com Certification Statement: I certify,under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision;that the information provided in the form is,to the best of my knowledge and belief,true,accurate,and complete;and that the engineering plans, specifications,operation and maintenance agreements and other supporting information are consistent with the information provided here. Designer Signature of Designer 05/22/23 Seal Date DRAINAGE AREAS 1 Is this a high density project? No 2 If so,number of drainage areas/SCMs 0 3 Does this oroiect have low densit areas? Yes 4 If so number of low 4-ify drainage areas 1 Is all/part of this project subject to previous rule 5 versions? No FORMS LOADED DRAINAGE AREA INFORMATION Entire Site LID 1 4 Type of SCM 5 Total drainage area(sq ft 801504 801504 6 Onsite drainage area(sq ft 435600 435600 7 Offsite drainage area(sq ft 374904 374904 8 Total BUA in project(sq ft) 104108 sf 104108 sf New BUA on subdivided lots(subject to 9permitting) s ft 71071 sf 71071 sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 33037 sf 33037 sf 11 Offsite BUA(sq ft 12 Breakdown of new BUA not on subdivided lots: -Parking(sq ft -Sidewalk(sq ft 4415 sf 4415 sf -Roof(sq ft -Roadway s ft 28622 sf 28622 sf -Future(sq ft -Other,please specify in the comment box below(sq ft New infiltrating permeable pavement on 13 subdivided lots(sq ft New infiltrating permeable pavement not on 14 subdivided lots(sq ft Existing BUA that will remain(not subject to 15permitting) s ft 16 Existina BUA that is already permitted (sq ft 17 Existing BUA that will be removed(sq ft 18 Percent BUA 24% 24% 19 Design storm inches 20 Design volume of SCM cu ft 21 Calculation method for design volume ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): LOW DENSITY DESIGN REQUIREMENTS FOR LOW DENSITY PROJECTS FROM 021-1.1003 1 Is project below density thresholds set forth in the applicable stormwater rule? Yes 2 Does project maximize dispersed flow and minimize channelization of flow? Yes 3 Has the use of piping been minimized per.1003(2)(c)? Yes 4 Side slopes of the vegetated conveyances(H:V) 31 5 1 Maximum velocity in the vegetated conveyances during the 10-year storm? 3.97 6 JAre curb outlet swales proposed? Yes 7 Maximum longitudinal slope of curb outlet swale(s)(%) 0 8 Bottom width of curb outlet swale(s)(feet) 4 It 9 Maximum side slope of curb outlet swale(s)(H:V) 3:1 10 Minimum length of curb outlet swale(s)(feet) 858 It 11 Are treatment swales used instead of curb outlet swales? No 12 Is stormwater released at the edge of the setback as dispersed flow? Yes 13 Have stormwater outlets been designed to prevent downslope erosion? Yes 14 Are variations to rule.1003 proposed? No ADDITIONAL INFORMATION 15 1piease use this space to provide any additional information about this low density project: Level Spreader 10-yr discharge=0.74 cfs at 044 fps Swale Drainage BUA Pervious Q Slope V,,,o,,. V,ttw, Flow depth # Area (ac) area C (cfs) (/) (fps) (fps) (ft) ac ac 1 18.40 2.39 16.01 0.35 34.60 0.00 5.00 3.97 1.86 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 TREATMENT SWALE 1 Drainage area number 1 2 Design flow rate of SCM cfs 16.60 cfs GENERAL MDC FROM 02H.1050 3 Is the SCM sized to treat the SW from all surfaces at build-out? Yes 4 Is the SCM located away from contaminated soils? Yes 5 What are the side slopes of the SCM(H:V)? 3:1 6 Does the SCM have retaining walls,gabion walls or other No engineered side slopes? 7 Are the inlets,outlets,and receiving stream protected from erosion Yes (1 0-yearstorm)? 8 Is there an overflow or bypass for inflow volume in excess of the No design volume? 9 What is the method for dewatering the SCM for maintenance? Pump(preferred) 10 If applicable,will the SCM be cleaned out after construction? Yes 11 Does the maintenance access comply with General MDC(8)? Yes 12 Does the drainage easement comply with General MDC(9)? Yes 13 If the SCM is on a single family lot,does(will?)the plat comply with Yes General MDC 10? 14 Is there an O&M Agreement that complies with General MDC(11)? Yes 15 Is there an O&M Plan that complies with General MDC(12)? Yes 16 Does the SCM follow the device specific MDC? Yes 17 Was the SCM designed by an NC licensedprofessional? Yes TREATMENT SWALE MDC FROM 02H.1061 18 SHWT elevation(fmsl) 185 19 Bottom of the treatment swale(fmsl) 197.00 20 Depth of treatment swale(feet) 3 cf 21 Is the swale trapezoidal in shape? Yes 22 Width of bottom of swale(feet) 4 ft 23 Side slopes of treatment swale(H:V) 3:1 24 Length of swale(feet) 858 ft 25 Flow depth during the 0.75 inch/hour storm(inches) in 26 Flow velocity during the 0.75 inch/hour storm(feet per second) cfs 27 Hydraulic retention time for swale(minutes) min 281 Species of grass that will be used Fescue 29 Will the grass be maintained at an average height of 6 inches? Yes 30 Will the grass not be cut lower than 4 inches? No 31 Velocity during the 10-year storm(feet per second) 3 ft/s 32 Is the swale designed to non-erosively pass the 10-year storm? Yes ADDITIONAL INFORMATION Please use this space to provide any additional information about 33 the treatment swale(s): Level Spreader designed with swale retention that discharges the 10-yr storm flow at 0.74 cfs with a velocity of 0.44 fps TrSwale 1 1:57 PM 5/4/2023 Operation & Maintenance Agreement Project Name: Carter Farms Subdivision - Phase 1 Project Location: Cover Page Maintenance records shall be kept on the following SCM(s). This maintenance record shall be kept in a log in a known set location. Any deficient SCM elements noted in the inspection will be corrected, repaired, or replaced immediately. These deficiencies can affect the integrity of structures, safety of the public, and the pollutant removal efficiency of the SCM(s). The SCM(s) on this project include (check all that apply & corres onding O&M sheets will be added automatically): Infiltration Basin Quantity: Location(s): Infiltration Trench Quantity: Location(s): Bioretention Cell Quantity: Location(s): Wet Pond Quantity: Location(s): Stormwater Wetland Quantity: Location(s): Permeable Pavement Quantity: Location(s): Sand Filter Quantity: Location(s): Rainwater Harvesting Quantity: Location(s): Green Roof Quantity: Location(s): Level Spreader- Filter Strip Quantity: Location(s): Proprietary System Quantity: Location(s): Treatment Swale Quantity: 1 Location(s): North Side of Development Dry Pond Quantity: Location(s): Disconnected Impervious Surface Present: No Location(s): User Defined SCM Present: No Location(s): Low Density Present: No Type: I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed for each SCM above, and attached O&M tables. I agree to notify NCDEQ of any problems with the system or prior to any changes to the system or responsible party. Responsible Party: Rheibeck Investments, LLC. - Geoff Becker Title & Organization: Owner/Developer Street address: 3727 Legion road City, state, zip: Hope Mills, NC 28348 Phone number(s): (910) 426-7575 Email: Signature: Date: 05/22/23 I, Mary B. Averette a Notary Public for the State of North Carolina County of Hoke do hereby certify that Daivd Geoff Becker personally appeared before me this 22nd day of May, 2023 and acknowledge the due execution of the Operations and Maintenance Agreement . Witness my hand and official seal, Seal My commission expires July 20, 2023 STORM-EZ 5/4/2023 Version 1.5 O&M Agreement Page 1 of 1 - Phase 1 or Page 1<ob ng SCM(s). This maintenance record shall be kept in a log in a known set location. in ifie inspection will be corrected, repaired, or replaced immediately. These deficiencies can safety of the public, and the pollutant removal efficiency of the SCM(s). this pro}ect include (check all that apply &corresponding O&M sheets will be added automatically): Infiltration Basin Quantity: Location(s): Infiltration Trench Quantity: Location(s): Bioretention Cell Quantity: Location(s): Wet Pond Quantity: Location(s): Stormwater Wetland Quantity: Location(s): Permeable Pavement Quantity: Location(s): Sand Filter Quantity: Location(s): Rainwater Harvesting Quantity: Location(s): Green Roof Quantity: Location(s): Level Spreader- Filter Strip Quantity: Location(s): Proprietary System Quantity: Location(s): Treatment Swale Quantity: 1 Location(s): North Side of Development Dry Pond Quantity: Location(s): Disconnected Impervious Surface Present:MNo Location(s): User Defined SCM Present: Location(s): Low Density Present: Type: acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed for ach SCM above, and attached O&M tables. I agree to notify NCDEQ of any problems with the system or prior to any changes to to system or responsible party. Responsible Party: Rheibeck Investments, LLC.-Geoff Becker Title& Organization: Owner/Developer Street address: 3727 Legion road City, state, zip: Hope Mills, NC 28348 Phone number(s): (910)426-7576 Email: Signature: Date: 45/22/23 Mary B. Averette a Notary Public for the State of North Carolina �ounty of Hoke do hereby certify that Daivd Geoff Becker ersonally appeared before me this 22nd day of May, 2023 and cknowledge the due execution of the Operations and Maintenance Agreement . *tness my hand and official seal, 33113I311,)!!tf 140TARy pUBLI C / My commission expires July 20, 2023 RM-EZ 514/20. Treatment Swale Maintenance Requirements Important operation and maintenance procedures: The drainage area of the grassed swale will be carefully managed to reduce the sediment load to the grassed swale. After the initial fertilization to establish the grass in the swale, fertilizer will not be applied to the treatment swale. The grassed swale will be inspected quarterly. Records of operation and maintenance shall be kept in a known set location and shall be available upon request. section activities shall be performed as follows. Any problems that are found shall be repaired immediately. SCM element: Potential problem: How to remediate the problem: Remove the trash/debris. Areas of bare soil egra e the soil if necessary to remove the gully, re- and/or erosive gullies sod (or plant with other appropriate species) and water have formed. until established. Provide lime and a one-time fertilizer application. Sediment covers the grass at the bottom of Remove sediment and dispose in an area that will not the Swale. impact streams or SCMs. Re-sod if necessary. The entire length of Vegetation is too short Maintain grassed vegetation such that the swale or the swale or too long. vegetated area does not erode during the peak flow from the 10-year storm Determine the source of the problem: soils, Grass is dead, hydrology, disease, etc. Remedy the problem and diseased or dying. replace plants. Provide a one-time fertilizer application to establish the ground cover if necessary. woody vegetation are treatment swale, regrade the treatment swale if present in the necessary and re-establish grass as shown on the Clogging has Clean out the outlet device. Dispose of the sediment occurred. off-site. The outlet device (if applicable) The outlet device is Repair or replace the outlet device. damaged Erosion or other signs Repair the damage and improve the flow dissipation of damage have structure. occurred at the outlet. The receiving water Discharges from the treatment swale are causing erosion or Contact the local NCDEQ Regional Office. sedimentation in the receivinq water. Permit Number: (to be provided by DWQ) flF wAr�R `=' r NCDENR p STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM GRASSED SWALE SUPPLEMENT This form must be filled out,printed and submitted. The Required Items Checklist(Part III)must also be filled out,printed and submitted along with all of the required information. I. PROJECT INFORMATION Project name Carter Farms Subdivision-Phase 1 Contact name Averette Engineering Co.,P.A. Phone number (910)488-5656 Date May 18,2022 Drainage area number PD 1 II. DESIGN INFORMATION Site Characteristics Drainage area 801,504.00 ftz Impervious area 104,108.00 ftZ Percent impervious 13.0%% Design rainfall depth 3.04 inch Peak Flow Calculations 10-yr storm runoff depth 5.44 in 10-yr storm intensity 5.38 in/hr Post-development 10-yr storm peak flow 34.60 ft/sec Velocity Velocity Maximum non-erosive velocity(peak 10-year storm) 5.00 ft/sec Soil characteristics(enter'Y'below) Sand/silt(easily erodible) X Clay mix(erosion resistant) Grass Type(enter'Y'below) Bermuda x Tall fescue Bah iag rass Kentucky bluegrass Grass-legume mixture Swale type: Fill out one of the options below: Option 1: Curb Outlet Swale: Y (Y or N) Maximum velocity 3.60 OK Side slopes 3.00 :1 Insufficient side slopes.Max is 5:1. Swale length 858.00 ft OK Option 2: Swale Seeking Pollutant Credit("For-Credit"Swale): (Y or N) Maximum velocity for 10-yr storm ft/sec Side slopes :1 Swale length ft Form SW401-Grassed Swale-Rev.4 Parts I and 11.Project Design Summary,Page 1 of 2 Permit Number: (to be provided by DWQ) Swale Characteristics Swale Shape: Enter an'Y'in the appropriate cell below: Trapezoidal Parabolic V-shaped X Width of the bottom of the Swale ft Width of the top of the Swale ft Additional Information Is the Swale sized for all runoff from ultimate build-out? Y(Y or N) OK Is the BMP located in a proposed drainage easement with a Y(Y or N) OK recorded access easement to a public Right of Way(ROW)? What is the distance from the bottom of the Swale to the SHWT? 12.00 ft OK What is the ground level elevation? 201.00 fmsl What is the elevation of the bottom of the Swale? 197.00 fmsl What is the SHWT elevation? 185.00 fmsl What is the longitudinal slope of the Swale? 0.10 % OK What is the depth of freeboard? 0.67 ft OK Form SW401-Grassed Swale-Rev.4 Parts I and 11.Project Design Summary,Page 2 of 2 Permit No: (to be assigned by DWQ) III. REQUIRED ITEMS CHECKLIST Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to indicate the following design requirements have been met. If the applicant has designated an agent,the agent may initial below. If a requirement has not been met, attach justification. Initials Pagel Plan Sheet No. MA C5 1. Plans(1"=50'or larger)of the entire site showing: -Design at ultimate build-out, -Off-site drainage(if applicable), -Delineated drainage basins(include Rational C coefficient per basin), -Swale dimensions(width, length,depth), -Maintenance access, -Proposed drainage easement and public right of way(ROW), -Grass species,and -Boundaries of drainage easement. MA C7 2. Plan details(1"=50'or larger)for the grassed swale showing: -Swale dimensions(width, length,depth), -Maintenance access, -Proposed drainage easement and public right of way(ROW), -Design at ultimate build-out, -Grass species, -Off-site drainage(if applicable),and -Boundaries of drainage easement. MA C16 3. Section view of the grassed swale(1"=20'or larger)showing: -Side slopes, -Longitudinal slope, -Freeboard -Swale dimensions,and -SHWT level(s) MA 4. Supporting calculations(including maximum velocity calculations for applicable storms) MA 5. A copy of the signed and notarized operation and maintenance(0&M)agreement. MA 6. A copy of the deed restrictions(if required). SW401-Grassed Swale-Rev.3 Part III, Page 1 of 1