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HomeMy WebLinkAboutNorth Carolina Agricultural Sciences Center - C16123 - Stormwater Impact Analysis (2) Stormwater Impact Analysis SCM Report For the proposed North Carolina Agricultural Sciences Center Raleigh, North Carolina Prepared for The State of North Carolina Prepared By Stewart Inc. September 21, 2018 Revised November 7, 2018 Stormwater Impact Analysis for North Carolina Agricultural Science Center Raleigh, North Carolina Prepared for: The State of North Carolina Prepared by: Stewart Inc. Firm License No. 1051 223 S. West Street, Suite 1100 Raleigh, NC 27603 919.380.8750 FOR REVIEW ONLY Stewart Project No. C16123 September 21, 2018 Revised November 7, 2018 STORMWATER IMPACT ANALYSIS NORTH CAROLINA AGRICULTURAL SCIENCES CENTER RALEIGH, NORTH CAROLINA EXECUTIVE SUMMARY This Stormwater Impact Analysis has been prepared specifically to address the requirements of the State of North Carolina’s Stormwater Design Manual to quantify the impact of the proposed development’s effect upon nutrient levels on downstream systems. Specifically, the Neuse River Buffer Rule (15A NCAC 02B.0233) requires that diffuse flow be provided into Zone 2 of the buffer associated with the stream adjacent to the proposed development. The stream is a tributary of Macon Pond which flows into Richlands Creek. The stream is subject to the Neuse River Buffer Rules because it is depicted on the latest 1:24,000 (7.5 minute) United States Geologic Survey (USGS) and the soil survey map prepared by the Natural Resource Conservation Service. The Neuse River Buffer Rule also requires no increase in peak flow from the 1-year, 24-hour storm event. Per the State of North Carolina’s Stormwater Design Manual, as a High-Density development, the post-development 10-year, 24-hour storm event must be safely conveyed in a vegetated channel in such a way that it does not cause erosion. The Total Nitrogen Export for the site must also be held to 3.6 lbs/ac/yr. The Total Nitrogen Export (TNE) from the site was calculated using the apportioning method to calculate the nutrient impacts on the site. Using this method, the “area of new development” is 38.71 ac (7.102 ac of additional impervious and 31.61 ac of apportioned open space). The TNE for the “area of new development” is 4.87 lb/ac/yr. This export was reduced to 3.39 lb/ac/yr (meeting the export threshold of 3.6 lb/ac/yr) by treatment of a 7.260 ac of impervious area at 35% removal rate. As is detailed below, there are three points of analysis for this site. The peak flow rate in the post-development condition is 4.98 cfs, 1.70 cfs, and 4.56 cfs, at the north, east, and south outlets respectively for the 1-year, 24-hour event. The peak flow rate in the post-development condition is 55.64 cfs, 6.50 cfs, and 18.24 cfs, at the north, east, and south outlets respectively for the 10-year, 24-hour event. All analysis points are proposed to be fitted with oversized riprap dissipation pads to provide further velocity reduction. Site Information The proposed North Carolina Agricultural Sciences Building will be located in Raleigh, Northeast of downtown toward William B. Umstead State Park. Currently the site consists of 1074 acres which contain forest, pasture lands, and minimal impervious. Numerous State-owned buildings dot the property, including Prairie Ridge Ecostation and motor fleet management. Only a fraction of the parcel will be used for the proposed development, which will sit on 40.12 acres at the corner of Edwards Mill and Reedy Creek Rd. This area of 40.12 acres is considered the “project area” for low-density development calculations. Figure 1.0 – Vicinity Map for the Proposed Agricultural Sciences Center This analysis is for the proposed improvements to the site, which will include bioswales in multiple locations to treat stormwater runoff. Additionally, a bioretention cell located in the northeastern quadrant of the site will treat an 9.07- acre drainage area with 63.4% of the area being impervious surfaces. A stepped bioswale in the southeastern quadrant will be used to treat 2.49-acres, 60.3% of the area being impervious surfaces. In the predevelopment condition there are 11,250 sf (0.25 ac) of impervious area, resulting in 0.644% impervious in the 40.12 acre project area. In the proposed condition there are 325,735 sf (7.48 ac) of impervious area, resulting in 18.63% impervious in the 40.12 acre project area. This is within the allowed 24% impervious for low-density development. Due to the concentration of impervious within the southern part of the project area, the project is being permitted as high density. The site is within the Neuse River Basin and drains to the Richlands Creek watershed. The property is not within a noted FEMA Floodplain. The Wake County Soil Survey Map indicates the soils on site consist mainly of sandy loams, which are classified as Hydrologic Soil Group B. Proposed Improvements The proposed improvements associated with this project include a 220,000 SF science building which will include labs and offices for five State agencies within the Department of Agriculture. Additionally, there will be parking lots for the building, and a loop road which will provide connectivity between the proposed parking lots and Reedy Creek Rd. The runoff from two-thirds of the roof and parking lots, as well as much of the road, will be directed to the proposed bioretention area. Most runoff from the parking lots located north of the building will first be directed to bioswales to be located between parking aisles before being directed to the bioretention area via a series of stormwater pipes. Stormwater runoff from the remaining third of the building and parking lots will be directed to the proposed stepped bioswale facing Reedy Creek Rd. Overall Results / Summary Peak Flow Analysis The table below includes the pre- and post-development peak flow for the 1 1-year, and 10-year, 24-hour storms and the associated percent change. The peak flow in the proposed condition is reduced for the 1-year, 24-hour event at all analysis points. See Appendix 3 for detailed calculations. Table 1.0 – Pre and Post Peak Flow Rates: PEAK FLOW SUMMARY (CFS) Return Period Analysis Point PRE POST (no detention) POST with detention % CHANGE 1 YR NORTH 5.38 24.79 4.98 -7.53% EAST 2.69 1.70 -36.65% SOUTH 4.61 9.75 4.56 -1.19% 10 YR NORTH 34.17 65.29 55.64 62.84% EAST 10.70 6.50 -39.25% SOUTH 16.35 27.99 18.24 11.52% Table 2.0 – Pre and Post Peak Velocity: Velocity Summary Table (ft/sec) PRE POST STORM EVENT DRAINAGE AREA w/o detention w/ detention % DIFF 1-YR NORTH 2.76 4.14 2.63 -5% EAST 3.38 3.16 -7% SOUTH 7.44 9.8 8.16 10% 10-YR NORTH 4.84 5.3 5.09 5% EAST 5.27 4.87 -8% SOUTH 10.01 11.97 11.22 12% Engineer’s Conclusion Because of the increase in the peak flows from the new development, a bioretention device will be used in the northern portion of the site to provide peak flow attenuation and meet diffuse flow requirements into zone 2 of the stream. The peak flow in the southern part of the property is proposed to be mitigated by a stepped bioswale and, as is shown in table 1.0. Each drainage area has been designed to utilize vegetated conveyance to not produce erosive velocities. All peak flow calculations have been included within this report. Submitted 21st day of September 2018 by STEWART Resubmitted 7th day of November 2018 by STEWART Joseph Puckett, PE Appendix 2 Site Information a. Aerial Map b. QUAD Map c. FEMA Map d. Soils Map e. Rainfall Data Hydrologic Soil Group—Wake County, North Carolina (Co-Located Labs) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/29/2016 Page 1 of 4396540039655003965600396570039658003965900396600039661003966200396630039664003966500396540039655003965600396570039658003965900396600039661003966200396630039664003966500706200706300706400706500706600706700706800706900707000 706200 706300 706400 706500 706600 706700 706800 706900 707000 35° 49' 17'' N 78° 43' 4'' W35° 49' 17'' N78° 42' 28'' W35° 48' 39'' N 78° 43' 4'' W35° 48' 39'' N 78° 42' 28'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84 0 250 500 1000 1500 Feet 0 50 100 200 300 Meters Map Scale: 1:5,830 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Wake County, North Carolina (NC183) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI AgC2 Appling gravelly sandy loam, 6 to 10 percent slopes, moderately eroded B 0.1 0.1% ApB Appling sandy loam, 2 to 6 percent slopes B 10.2 10.1% ApC Appling sandy loam, 6 to 10 percent slopes B 7.2 7.1% ApC2 Appling sandy loam, 6 to 10 percent slopes, moderately eroded B 1.6 1.5% ApD Appling sandy loam, 10 to 15 percent slopes B 8.4 8.3% CeD Cecil sandy loam, 10 to 15 percent slopes A 17.2 17.0% CgB2 Cecil gravelly sandy loam, 2 to 6 percent slopes, moderately eroded B 24.0 23.7% CgC2 Cecil gravelly sandy loam, 6 to 10 percent slopes, moderately eroded B 18.2 17.9% CmA Chewacla sandy loam, 0 to 2 percent slopes, frequently flooded B/D 0.5 0.5% CnA Colfax sandy loam, 0 to 3 percent slopes C/D 0.0 0.0% MeA Mantachie sandy loam, 0 to 2 percent slopes, rarely flooded B/D 4.9 4.8% PaF Pacolet sandy loam, 15 to 45 percent slopes B 1.5 1.5% W Water 2.6 2.6% WmE Wedowee sandy loam, 15 to 25 percent slopes B 1.4 1.4% WyA Worsham sandy loam, 0 to 3 percent slopes D 3.6 3.5% Totals for Area of Interest 101.5 100.0% Hydrologic Soil Group—Wake County, North Carolina Co-Located Labs Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/29/2016 Page 3 of 4 Project: NCDA&CS Date: 11.6.2018 Revision:- Project No:C16123 By:NBC North Drainage Area to Bioretention Input values in red 395,275 144,615 395,275 0 0 0 144,615 73,728 57,542 86,904 27,510 4,976 0 0 0 250,660 9.07 ac 5.75 ac 63.41 % Design Rainfall 1.0 in "Simple Method" Formula Rv = 0.05+0.009(I) where Rv=0.62 in/in Controlled Volume Calculation Volume = (Design Rainfall) (Rv) (Drainage Area) Volume =0.47 ac-ft Volume =20446 cf <----- Total Volume Required to be Controlled (Storage) * = Report only amount of existing BUA that will reamain after develoipment. Do not report any existing BUA that is to be removed and which will be replaced by new BUA On-site Parking (sf) Pervious Surface Area Managed Pervious Area (sf) Unmanged Pervious Area (pasture) (sf) Forest (sf) Total Pervious Area (sf) Total Drainage Area (sf) Other On-site (sf) Future (sf) Off-site (sf) Existing BUA* (sf) Total Impervious Area (sf) Off-site Drainage Area (sf) Impervious Surface Area On-site Buildings/Lots (sf) On-site Streets (sf) On-site Drainage Area (sf) On-site Sidewalks (sf) Bioretention Area Sizing Runoff Volume - Simple Method Drainage Area Percent Impervious This volume of runoff must be stored in the pond above the normal pool elevation and be released in a draw down period of 2 to 5 days. Rv = Runoff Coefficient = stormwater runoff (inches) / stormwater rainfall (inches) I = Percent Impervious = drainage area (acres) / impervious portion of the drainage area (acres) Impervious Area Drainage Area 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919. 380 8752 www.stewartinc.com Design Volume - Simple Project: NCDA&CS Date: 11.6.2018 Revision:- Project No:C16123 By:NBC North Drainage Area to Bioretention Input values in red 395,275 144,615 395,275 0 0 0 144,615 73,728 57,542 98 86,904 61 27,510 61 4,976 58 0 0 0 250,660 9.07 ac 5.75 ac 63.41 % Design Rainfall 1.0 in "NRCS" Formula S = (1000/CN) - 10 Q* = [(P - 0.2S) ^2] / (P + 0.8S) where S=0.204 Q*=0.79 in/in Controlled Volume Calculation Volume = (Design Rainfall) (Q*) (Drainage Area) Volume =0.38 ac-ft Volume =16521 cf <----- Total Volume Required to be Controlled (Storage) On-site Parking (sf) On-site Sidewalks (sf) Other On-site (sf) Bioretention Area Sizing Runoff Volume - NRCS Drainage Area Pervious Surface Area Total Drainage Area (sf)Managed Pervious Area (sf) On-site Drainage Area (sf)Unmanged Pervious Area (pasture) (sf) Off-site Drainage Area (sf)Forest (sf) Total Pervious Area (sf) Impervious Surface Area On-site Buildings/Lots (sf) On-site Streets (sf) Future (sf) Off-site (sf) Existing BUA* (sf) Drainage Area Impervious Area Percent Impervious Total Impervious Area (sf) P = Design rainfall (inches) Q* = Runoff Depth (inches) This volume of runoff must be stored in the bioretention area and be released in a draw down period of 12 to 72 hours. ** = if CN of non-directly-connected drainage area is less than 64, MDC allows assumption for zero runoff from this area. Therefore SCM water quality volume only accounts for contributing runoff from impervious area. * = Report only amount of existing BUA that will reamain after develoipment. Do not report any existing BUA that is to be removed and which will be replaced by new BUA Curve Number by Landuse Impervious area Managed Pervious Area, good condition ** Unmanged Pervious Area (pasture) Forest 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919. 380 8752 www.stewartinc.com Design Volume - NRCS Project: NCDA&CS Date: 11.6.2018 Revision:- Project No:C16123 By:NBC Input values in red Volume =20446 cf <----- Total Volume Required to be Controlled (Storage) Required Surface Area 1.00 ft Surface Area Calculation Surface Area = (Volume) / (Ponding Depth) Surface Area 20,446 sf Bio Retenion Area Volume Provided Stage Level Elevati on (ft) Area (ft2) Stage Volum e (ft3) Cumulat ive Storage (ft3) 0 415.5 20413 0 0 1 416.5 24621 22517 22517 OK Drawdown Time 22517 cf 24621 sf 1.00 in/hr Drain Time T = (Volume) / (Infiltration Rate) / (Surface Area) T =10.97 hours Ponding Depth Facility Volume Facility Surface Area Media Infiltration Rate Bio Retention Area Design Volume/Drawdown Time 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919. 380 8752 www.stewartinc.com Provided Volume Project: NCDA&CS Date: 11.6.2018 Revision:- Project No:C16123 By:NBC Input values in red Water Draw Through Rate: Darcy's Equation:Q = (.0000232)*K*A*( H/L ) where K = media infiltration rate A = Area H = Total Head L = Flow path length Provided Bio Retetion Area Values K =1.00 in/hr A =24621 SF H =4.67 ft L=3.92 ft Q =0.68 cfs Safety Factor 10 Adjusted Q =6.8001 cfs Minimum underdrain diameter Sizing Q =6.8001 cfs Slope =0.005 ft/ft n 0.011 unitless D =16.34 in Use:16 lines of 4" underdrain pipe or 8 lines of 6" underdrain pipe CALCULATION TABLE Equivalent Pipe Diameters at 0.5% slope If D is less than No. of 4" diam No of 6" diam 4 2 6 2 5.657 3 8.485 3 6.928 4 10.392 4 8.000 5 12.000 5 8.944 6 13.416 6 9.798 7 14.697 7 10.583 8 15.875 8 11.314 9 16.971 9 12.000 10 18.000 10 12.649 11 18.974 11 13.253 12 19.900 12 Bio Retention Area Underdrain Pipe Sizing Use Manning's Equation: If D is less than 8/3 5.0 *16   =S nQD 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919. 380 8752 www.stewartinc.com Underdrains Project: NCDA&CS Date: 9.19.2018 Revision:- Project No:C16123 By:NBC South Drainage Area to Stepped Bioretention Input values in red 108,517 42,929 108,517 0 0 0 42,929 11,087 603 39,242 14,656 0 0 0 0 65,588 2.49 ac 1.51 ac 60.44 % Design Rainfall 1.0 in "Simple Method" Formula Rv = 0.05+0.009(I) where Rv=0.59 in/in Controlled Volume Calculation Volume = (Design Rainfall) (Rv) (Drainage Area) Volume =0.12 ac-ft Volume =5371 cf <----- Total Volume Required to be Controlled (Storage) On-site Drainage Area (sf) On-site Sidewalks (sf) Bioretention Area Sizing Runoff Volume - Simple Method Drainage Area Percent Impervious This volume of runoff must be stored in the pond above the normal pool elevation and be released in a draw down period of 2 to 5 days. Rv = Runoff Coefficient = stormwater runoff (inches) / stormwater rainfall (inches) I = Percent Impervious = drainage area (acres) / impervious portion of the drainage area (acres) Impervious Area Drainage Area Off-site (sf) Existing BUA* (sf) Total Impervious Area (sf) Off-site Drainage Area (sf) Impervious Surface Area On-site Buildings/Lots (sf) On-site Streets (sf) * = Report only amount of existing BUA that will reamain after develoipment. Do not report any existing BUA that is to be removed and which will be replaced by new BUA On-site Parking (sf) Pervious Surface Area Managed Pervious Area (sf) Unmanged Pervious Area (pasture) (sf) Forest (sf) Total Pervious Area (sf) Total Drainage Area (sf) Other On-site (sf) Future (sf) 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919. 380 8752 www.stewartinc.com Design Volume - Simple Project: NCDA&CS Date: 9.19.2018 Revision:- Project No:C16123 By:NBC South Drainage Area to Stepped Bioretention Input values in red 108,517 42,929 108,517 0 0 0 42,929 11,087 603 98 39,242 61 14,656 61 0 58 0 0 0 65,588 2.49 ac 1.51 ac 60.44 % Design Rainfall 1.0 in "NRCS" Formula S = (1000/CN) - 10 Q* = [(P - 0.2S) ^2] / (P + 0.8S) where S=0.204 Q*=0.79 in/in Controlled Volume Calculation Volume = (Design Rainfall) (Q*) (Drainage Area) Volume =0.10 ac-ft Volume =4323 cf <----- Total Volume Required to be Controlled (Storage) Forest * = Report only amount of existing BUA that will reamain after develoipment. Do not report any existing BUA that is to be removed and which will be replaced by new BUA ** = if CN of non-directly-connected drainage area is less than 64, MDC allows assumption for zero runoff from this area. Therefore SCM water quality volume only accounts for contributing runoff from impervious area. Drainage Area Impervious Area Percent Impervious P = Design rainfall (inches) Q* = Runoff Depth (inches) This volume of runoff must be stored in the bioretention area and be released in a draw down period of 12 to 72 hours. On-site Parking (sf) On-site Sidewalks (sf) Other On-site (sf) Future (sf) Off-site (sf) Existing BUA* (sf) Total Impervious Area (sf) Managed Pervious Area, good condition ** Unmanged Pervious Area (pasture) Off-site Drainage Area (sf)Forest (sf) Total Pervious Area (sf) Impervious Surface Area On-site Buildings/Lots (sf) On-site Streets (sf) Curve Number by Landuse Impervious area Bioretention Area Sizing Runoff Volume - NRCS Drainage Area Pervious Surface Area Total Drainage Area (sf)Managed Pervious Area (sf) On-site Drainage Area (sf)Unmanged Pervious Area (pasture) (sf) 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919. 380 8752 www.stewartinc.com Design Volume - NRCS Project: NCDA&CS Date: 9.19.2018 Revision:- Project No:C16123 By:NBC Input values in red Volume =5371 cf <----- Total Volume Required to be Controlled (Storage) Required Surface Area 1.00 ft Surface Area Calculation Surface Area = (Volume) / (Ponding Depth) Surface Area 5,371 sf Bio Retenion Area Volume Provided Stage Level Elevati on (ft) Area (ft2) Stage Volum e (ft3) Cumulat ive Storage (ft3) 0 439 5445 0 0 1 440 9071 7258 7258 OK Drawdown Time 7258 cf 9071 sf 1.00 in/hr Drain Time T = (Volume) / (Infiltration Rate) / (Surface Area) T =9.60 hours Ponding Depth Facility Volume Facility Surface Area Media Infiltration Rate Bio Retention Area Design Volume/Drawdown Time 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919. 380 8752 www.stewartinc.com Provided Volume Project: NCDA&CS Date: 9.19.2018 Revision:- Project No:C16123 By:NBC Input values in red Water Draw Through Rate: Darcy's Equation:Q = (.0000232)*K*A*( H/L ) where K = media infiltration rate A = Area H = Total Head L = Flow path length Provided Bio Retetion Area Values K =1.00 in/hr A =9071 SF H =4.67 ft L=3.92 ft Q =0.251 cfs Safety Factor 10 Adjusted Q =2.5053 cfs Minimum underdrain diameter Sizing Q =2.5053 cfs Slope =0.005 ft/ft n 0.011 unitless D =11.24 in Use:8 lines of 4" underdrain pipe or 4 lines of 6" underdrain pipe CALCULATION TABLE Equivalent Pipe Diameters at 0.5% slope If D is less than No. of 4" diam No of 6" diam 4 2 6 2 5.651 3 8.485 3 6.921 4 10.392 4 7.992 5 12.000 5 8.935 6 13.416 6 9.788 7 14.697 7 10.572 8 15.875 8 11.302 9 16.971 9 11.988 10 18.000 10 12.636 11 18.974 11 13.253 12 19.900 12 Bio Retention Area Underdrain Pipe Sizing Use Manning's Equation: If D is less than 8/3 5.0 *16   =S nQD 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919. 380 8752 www.stewartinc.com Underdrains PEAK FLOW ANALYSIS – NC AGRICULTURAL SCIENCES CENTER STEWART Page | 1 PEAK FLOW SUMMARY (CFS)  Return  Period  Analysis  Point PRE POST (no detention)  POST with  detention  %  CHANGE  1 YR  NORTH 5.38 24.79 4.98 ‐7.53%  EAST 2.69 1.70   ‐36.65%  SOUTH 4.61 9.75 4.56 ‐1.19%  10 YR  NORTH 34.17 65.29 55.64 62.84%  EAST 10.70 6.50   ‐39.25%  SOUTH 16.35 27.99 18.24 11.52%  TIME 1YR PRE 1YR POST WITHOUT DETENTION 1YR POST WITH DETENTION  0.0833 0.0000 0.0000 0.0000  0.1667 0.0000 0.0000 0.0000  0.2500 0.0000 0.0000 0.0000  0.3333 0.0000 0.0000 0.0000  0.4167 0.0000 0.0000 0.0000  0.5000 0.0000 0.0000 0.0000  0.5833 0.0000 0.0000 0.0000  0.6667 0.0000 0.0000 0.0000  0.7500 0.0000 0.0000 0.0000  PEAK FLOW ANALYSIS – NC AGRICULTURAL SCIENCES CENTER STEWART Page | 41 TIME  10YR  PRE 10YR POST WITHOUT DETENTION  10YR POST WITH  DETENTION  0.0833 0.0000 0.0002 0.0002  0.1667 0.0000 0.0000 0.0000  0.2500 0.0000 0.0000 0.0000  0.3333 0.0000 0.0000 0.0000  0.4167 0.0000 0.0000 0.0000  0.5000 0.0000 0.0000 0.0000  0.5833 0.0000 0.0000 0.0000  0.6667 0.0000 0.0000 0.0000  0.7500 0.0000 0.0000 0.0000  0.8333 0.0000 0.0000 0.0000  0.9167 0.0000 0.0000 0.0000  1.0000 0.0000 0.0000 0.0000  1.0833 0.0000 0.0000 0.0000  1.1667 0.0000 0.0000 0.0000  1.2500 0.0000 0.0000 0.0000  1.3333 0.0000 0.0000 0.0000  1.4167 0.0000 0.0000 0.0000  1.5000 0.0000 0.0000 0.0000  Project Date 2018.09.20 Project No.Designer NBC Outlet ID Outlet flowrate 12.44 cfs Pipe diameter 24 inches EQUIVALENT PIPE AREA Outlet pipe slope 1.02 percent Full flow velocity 9.0 ft/sec Zone from graph above =2 Outlet pipe diameter 24 in.Length =12.0 ft. Outlet flowrate 12.4 cfs Width =6.0 ft. Outlet velocity 9.0 ft/sec Stone diameter =6 in. Material =Class B Thickness =22 in. Zone Material Diameter Thickness Length Width 1 Class A 3 9 4 x D(o)3 x D(o) 2 Class B 6 22 6 x D(o)3 x D(o) 3 Class I 13 22 8 x D(o)3 x D(o) 4 Class I 13 22 8 x D(o)3 x D(o) 5 Class II 23 27 10 x D(o)3 x D(o) 6 Class II 23 27 10 x D(o)3 x D(o) 7 Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual RIPRAP OUTLET PROTECTION WORKSHEET NC Agricultural Science Center C16123 HW-01 Special study required 9.0 ft/sec 0 5 10 15 20 25 0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft) Figure 8.06.b.1 Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919.380.8752 www.stewartinc.com Project Date 2018.09.20 Project No.Designer NBC Outlet ID Outlet flowrate 47.22 cfs Pipe diameter 30 inches EQUIVALENT PIPE AREA Outlet pipe slope 1.13 percent Full flow velocity 11.2 ft/sec Zone from graph above =3 Outlet pipe diameter 30 in.Length =20.0 ft. Outlet flowrate 47.2 cfs Width =7.5 ft. Outlet velocity 11.2 ft/sec Stone diameter =13 in. Material =Class I Thickness =22 in. Zone Material Diameter Thickness Length Width 1 Class A 3 9 4 x D(o)3 x D(o) 2 Class B 6 22 6 x D(o)3 x D(o) 3 Class I 13 22 8 x D(o)3 x D(o) 4 Class I 13 22 8 x D(o)3 x D(o) 5 Class II 23 27 10 x D(o)3 x D(o) 6 Class II 23 27 10 x D(o)3 x D(o) 7 Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual RIPRAP OUTLET PROTECTION WORKSHEET NC Agricultural Science Center C16123 HW-10 Special study required 11.2 ft/sec 0 5 10 15 20 25 0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft) Figure 8.06.b.1 Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919.380.8752 www.stewartinc.com Project Date 2018.09.20 Project No.Designer NBC Outlet ID Outlet flowrate 28.93 cfs Pipe diameter 30 inches EQUIVALENT PIPE AREA Outlet pipe slope 1 percent Full flow velocity 7.0 ft/sec Zone from graph above =2 Outlet pipe diameter 30 in.Length =15.0 ft. Outlet flowrate 28.9 cfs Width =7.5 ft. Outlet velocity 7.0 ft/sec Stone diameter =6 in. Material =Class B Thickness =22 in. Zone Material Diameter Thickness Length Width 1 Class A 3 9 4 x D(o)3 x D(o) 2 Class B 6 22 6 x D(o)3 x D(o) 3 Class I 13 22 8 x D(o)3 x D(o) 4 Class I 13 22 8 x D(o)3 x D(o) 5 Class II 23 27 10 x D(o)3 x D(o) 6 Class II 23 27 10 x D(o)3 x D(o) 7 Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual RIPRAP OUTLET PROTECTION WORKSHEET NC Agricultural Science Center C16123 HW-20 Special study required 7.0 ft/sec 0 5 10 15 20 25 0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft) Figure 8.06.b.1 Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919.380.8752 www.stewartinc.com Project Date 2018.09.20 Project No.Designer NBC Outlet ID Outlet flowrate 19.16 cfs Pipe diameter 30 inches EQUIVALENT PIPE AREA Outlet pipe slope 0.95 percent Full flow velocity 6.3 ft/sec Zone from graph above =2 Outlet pipe diameter 30 in.Length =15.0 ft. Outlet flowrate 19.2 cfs Width =7.5 ft. Outlet velocity 6.3 ft/sec Stone diameter =6 in. Material =Class B Thickness =22 in. Zone Material Diameter Thickness Length Width 1 Class A 3 9 4 x D(o)3 x D(o) 2 Class B 6 22 6 x D(o)3 x D(o) 3 Class I 13 22 8 x D(o)3 x D(o) 4 Class I 13 22 8 x D(o)3 x D(o) 5 Class II 23 27 10 x D(o)3 x D(o) 6 Class II 23 27 10 x D(o)3 x D(o) 7 Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual RIPRAP OUTLET PROTECTION WORKSHEET NC Agricultural Science Center C16123 HW-40 Special study required 6.3 ft/sec 0 5 10 15 20 25 0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft) Figure 8.06.b.1 Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919.380.8752 www.stewartinc.com Project Date 2018.09.20 Project No.Designer NBC Outlet ID Outlet flowrate 6.34 cfs Pipe diameter 18 inches EQUIVALENT PIPE AREA Outlet pipe slope 0.6 percent Full flow velocity 4.7 ft/sec Zone from graph above =1 Outlet pipe diameter 18 in.Length =6.0 ft. Outlet flowrate 6.3 cfs Width =4.5 ft. Outlet velocity 4.7 ft/sec Stone diameter =3 in. Material =Class A Thickness =9 in. Zone Material Diameter Thickness Length Width 1 Class A 3 9 4 x D(o)3 x D(o) 2 Class B 6 22 6 x D(o)3 x D(o) 3 Class I 13 22 8 x D(o)3 x D(o) 4 Class I 13 22 8 x D(o)3 x D(o) 5 Class II 23 27 10 x D(o)3 x D(o) 6 Class II 23 27 10 x D(o)3 x D(o) 7 Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual RIPRAP OUTLET PROTECTION WORKSHEET NC Agricultural Science Center C16123 HW-60 Special study required 4.7 ft/sec 0 5 10 15 20 25 0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft) Figure 8.06.b.1 Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919.380.8752 www.stewartinc.com Project Date 2018.09.20 Project No.Designer NBC Outlet ID Outlet flowrate 5.53 cfs Pipe diameter 15 inches EQUIVALENT PIPE AREA Outlet pipe slope 1 percent Full flow velocity 4.8 ft/sec Zone from graph above =2 Outlet pipe diameter 15 in.Length =7.5 ft. Outlet flowrate 5.5 cfs Width =3.8 ft. Outlet velocity 4.8 ft/sec Stone diameter =6 in. Material =Class B Thickness =22 in. Zone Material Diameter Thickness Length Width 1 Class A 3 9 4 x D(o)3 x D(o) 2 Class B 6 22 6 x D(o)3 x D(o) 3 Class I 13 22 8 x D(o)3 x D(o) 4 Class I 13 22 8 x D(o)3 x D(o) 5 Class II 23 27 10 x D(o)3 x D(o) 6 Class II 23 27 10 x D(o)3 x D(o) 7 Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual RIPRAP OUTLET PROTECTION WORKSHEET NC Agricultural Science Center C16123 HW-34 Special study required 4.8 ft/sec 0 5 10 15 20 25 0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft) Figure 8.06.b.1 Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919.380.8752 www.stewartinc.com Project Date 2018.09.20 Project No.Designer NBC Outlet ID Outlet flowrate 16.24 cfs Pipe diameter 24 inches EQUIVALENT PIPE AREA Outlet pipe slope 3.42 percent Full flow velocity 11.0 ft/sec Zone from graph above =2 Outlet pipe diameter 24 in.Length =12.0 ft. Outlet flowrate 16.2 cfs Width =6.0 ft. Outlet velocity 11.0 ft/sec Stone diameter =6 in. Material =Class B Thickness =22 in. Zone Material Diameter Thickness Length Width 1 Class A 3 9 4 x D(o)3 x D(o) 2 Class B 6 22 6 x D(o)3 x D(o) 3 Class I 13 22 8 x D(o)3 x D(o) 4 Class I 13 22 8 x D(o)3 x D(o) 5 Class II 23 27 10 x D(o)3 x D(o) 6 Class II 23 27 10 x D(o)3 x D(o) 7 Calculations based on NY DOT method - Pages 8.06.05 through 8.06.06 in NC Erosion Control Manual RIPRAP OUTLET PROTECTION WORKSHEET NC Agricultural Science Center C16123 Existing South Outlet Special study required 11.0 ft/sec 0 5 10 15 20 25 0 1 2 3 4 5 6 7 8 9 10Velocity (ft/sec)Pipe diameter (ft) Figure 8.06.b.1 Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 223 S. West Street, Suite 1100, Raleigh, NC 27603 Tel 919.380.8750 Fax 919.380.8752 www.stewartinc.com Existing Conditions Protected Open 25.16 ac Managed Open 14.70 ac Impervious 0.26 ac Total Project Area 40.12 ac Proposed Conditions Protected Open 25.16 ac Managed Open 7.59 ac Impervious 7.36 ac Total Project Area 40.12 ac Site Data Analysis - Nitrogen Calculations (Based upon total Parcel Area + ROW) Project:North Carolina Agricultural Sciences Center Number:C16123 Date:12-Sep-18 Total Parcel Area =40.12 ac Existing Imperious Area =0.26 ac Existing Open Space =39.86 ac Additional Proposed Impervious Area =7.102 ac Total Proposed Impervious Area =7.36 ac Remaining Open Space =32.76 ac "area" of new development =38.7122 ac (Add. Prop imp + apprortioned open space)Min. Nitrogen to be removed from site =49.13 lb/yr (Tot. Prop. Export-3.6)*"area" of new develop.) to meet 3.6 lb/ac/yr for new "area" Apportioned open space =31.6104 ac (ex. imp/prop. Imp*remaining open space) Minimum area of imp. To bioretention =6.621 ac (TN to be removed/0.35/21.2) Proposed Nitrogen Load =188.490 lb/yr Min. Nitrogen to be removed from site =-198.63 lb/yr (Tot. Prop. Export-3.6)*"area" of new develop.) Total Proposed Nitrogen Export =4.87 lb/ac/yr (Prop. Nitrogen Load/"area" of new develop.)to meet 10 lb/ac/yr for new "area" for "area" of new development Minimum area of imp. to bioretention =-26.770 ac (TN to be removed/0.35/21.2) Total Prop. Nitrogen Export for "area" of new development with Treatment Removal by BMP Drainage area to BMP 11.420 ac Effective removal rate 35% Proposed Nitrogen Export with Treatment Total TN Export Treatment TN Export Area Amount Reduced (ac)(lbs/yr)lbs/yr (lbs/yr) To BMP 11.420 163.203 57.121 106.082 Remaining Site 21.534 17.040 0.000 17.040 Total Area =32.954 123.122 Proposed Nitrogen Load =188.490 lb/yr Total Nitrogen removed by BMP =57.121 lb/yr Prop. Nitrogen Load with treatment =131.369 lb/yr Total Proposed Nitrogen Export =3.39 lb/ac/yr for "area" of new development with treatment Buydown Payment Calculation Nitrogen Limit =3.6 lbs/ac/yr Total Parcel Area =38.71 ac Total Nitrogen Export =3.39 lbs/ac/yr Payment =$850.50 ac/lbs Payment =$0.00 [(Add. prop imp*21.2)+(app. open space*1.2)] "area" of new development Total Nitrogen Export (Using Apportioning Method) Step 1: Determine area for each type of land use and enter in Column (2). Step 2: Total the areas for each type of land use and enter at the bottom of Column (2). Step 3: Multiply the areas in Column (2) by the TN export Coefficients in Column (3) and enter in Column (4). Step 4: Total the TN exports for each type of land use and enter at the bottom of Column (4). Step 5: Determine the export coefficient for site by dividing the total TN export from uses at the bottom of Column (4) by the area at the bottom of Column (2). (1)(2)(3)(4) Type of Land Cover Areas TN export coefficient TN export from use (acres)(lbs/ac/yr)(lbs/yr) Permanently protected 25.164 0.60 15.099 undisturbed open space (forest, unmown meadow) Permanently protected 14.697 1.2 17.637 open space (grass, landscaping, etc.) Impervious surfaces 0.258 21.2 5.475 (roads, parking lots, driveways, roofs, paved storage areas, etc.) TOTAL 40.120 ---38.211 Total Nitrogen Export =0.95 lb/ac/yr Existing Nitrogen Runoff Calculations Total Parcel Step 1: Determine area for each type of land use and enter in Column (2). Step 2: Total the areas for each type of land use and enter at the bottom of Column (2). Step 3: Multiply the areas in Column (2) by the TN export Coefficients in Column (3) and enter in Column (4). Step 4: Total the TN exports for each type of land use and enter at the bottom of Column (4). Step 5: Determine the export coefficient for site by dividing the total TN export from uses at the bottom of Column (4) by the area at the bottom of Column (2). (1)(2)(3)(4) Type of Land Cover Areas TN export coefficient TN export from use (acres)(lbs/ac/yr)(lbs/yr) Permanently protected 25.164 0.60 15.099 undisturbed open space (forest, unmown meadow) Permanently protected 7.593 1.2 9.112 open space (grass, landscaping, etc.) Impervious surfaces 7.360 21.2 156.033 (roads, parking lots, driveways, roofs, paved storage areas, etc.) TOTAL 40.118 ---180.243 Total Nitrogen Export =4.49 lb/ac/yr Proposed Nitrogen Runoff Calculations Total Parcel - BEFORE TREATMENT Step 1: Determine area for each type of land use and enter in Column (2). Step 2: Total the areas for each type of land use and enter at the bottom of Column (2). Step 3: Multiply the areas in Column (2) by the TN export Coefficients in Column (3) and enter in Column (4). Step 4: Total the TN exports for each type of land use and enter at the bottom of Column (4). Step 5: Determine the export coefficient for site by dividing the total TN export from uses at the bottom of Column (4) by the area at the bottom of Column (2). (1)(2)(3)(4) Type of Land Cover Areas TN export coefficient TN export from use (acres)(lbs/ac/yr)(lbs/yr) Permanently protected 7.163 0.60 4.298 undisturbed open space (forest, unmown meadow) Permanently protected 4.160 1.2 4.992 open space (grass, landscaping, etc.) Impervious surfaces 7.260 21.2 153.913 (roads, parking lots, driveways, roofs, paved storage areas, etc.) TOTAL 11.420 ---163.203 Total Nitrogen Export =14.29 lb/ac/yr Proposed Nitrogen Runoff Calculations To BMP Step 1: Determine area for each type of land use and enter in Column (2). Step 2: Total the areas for each type of land use and enter at the bottom of Column (2). Step 3: Multiply the areas in Column (2) by the TN export Coefficients in Column (3) and enter in Column (4). Step 4: Total the TN exports for each type of land use and enter at the bottom of Column (4). Step 5: Determine the export coefficient for site by dividing the total TN export from uses at the bottom of Column (4) by the area at the bottom of Column (2). (1)(2)(3)(4) Type of Land Cover Areas TN export coefficient TN export from use (acres)(lbs/ac/yr)(lbs/yr) Permanently protected 18.001 0.60 10.801 undisturbed open space (forest, unmown meadow) Permanently protected 3.433 1.2 4.120 open space (grass, landscaping, etc.) Impervious surfaces 0.100 21.2 2.120 (roads, parking lots, driveways, roofs, paved storage areas, etc.) TOTAL 21.534 ---17.040 Total Nitrogen Export =0.79 lb/ac/yr Proposed Nitrogen Runoff Calculations Remaining portion of parcel with NO TREATMENT Appendix 4 Stormwater Drawings a. SW1.0- Pre-Development Land Use b. SW2.0- Post-Development Land Use c. SW3.0- Pre-Development Drainage Area d. SW4.0- Post-Development Drainage Area GVWVWVWVWVWVF F = 4 4 7 . 4 1 ' FF=438.26'FF=433.76'FF=436.90'14QR14QR14QR14QR14AR10AR10AR8AR12AR8AR6AR10AR10AR24AR28AR24AR24AR14QR14QR14QR20QR8QR14QR18QR8QR16QR16QR24QR12QR6QR12QR12QR16QR42LS36QA48QA5PY5PY6PT9PT3CF4PY4LS6LS7PT3PY3PY6TREE5TREE5TREE8TREE7TREE40QA40QA30QA30QR8TREE8TREE8TREE40QR4JV3AR7TREE5TREE7TREE22LS8QP26LS15LS4PY5PY4QRVAULT36QA40QA12JV40QA34QAG A T E GATEGATEGATEGA T E GATECONTROL POINTN:751803.84'E:2085432.48'EL:428.28'EDWARDS MILL ROADSR 3009VARIABLE WIDTH PUBLIC R/WREEDY CREEK ROADVARIABLE WIDTH PUBLIC R/WREEDY CREEK ROADVARIABLE WIDTH PUBLIC R/WWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAGIS ZONING LINE"AP""OX-3"GIS ZONING LINE"AP""OX-3"15"RCP15"RCP15"RCP8"PVC4"PVC8"PVC8"PVC 8" P V C 15"RCP24"RCP24"RCP24"RCPTOC=434.52'IN=429.32'OUT=429.12'TOC=435.19'IN=428.89'OUT=428.69'15"RCPTOC=408.90'OUT=404.70'15"RCPTOC=399.70'IN(15")=394.10'IN(18")=394.20'OUT=393.95'TOC=400.42'OUT=395.82'INV=420.14'18 " R C PTOC=408.12'IN=403.12'OUT=402.72'GWPGATETOC=446.46'OUT=441.31'15"RCPTOC=441.89'IN=432.89'OUT=432.29'INV=429.62'24 " R C P INV=433.29'INV=436.90'TOC=442.72'OUT=437.77'TOC=444.89'IN(4")=441.29'IN(15")=437.09'OUT=436.89'INV=435.98'RIM=444.83'IN(4")=439.43'IN(8")=440.15'IN(15")=437.93'OUT=437.73'RIM=444.98'IN=439.18'IN=439.18'OUT=438.88'SIGNSIGNTPEDGRAVELRWMEIREIREIPRWMS49°11'35"W 585.30'N60°48'20"W 169.00'N09°54'07"W 120.90'N32°32'49"E 57.90' N 3 2 ° 2 9 ' 2 3 " EC1C2L1L2 N50°51'53"WRWMASPHALT SIGNGATEEE E 15"RCPASPHALTPARKINGASPHALTPARKINGASPHALTPARKINGRIPRAPFEEDERPADFEEDERPAD4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCESPIGOT8"PVC15"RCP8"PVC8"PVCRIM=391.78'IN=381.48'OUT=381.46'RIM=391.93'IN=384.93'OUT=383.07'S60°48'20"E76.65'TPEDN50°51'53"WTIMBER TIMBER 15"RCPTOC=398.48'OUT=394.38'TOC=398.47'IN=394.37'OUT=394.17'TOC=397.93'IN(15")=392.83'IN(24")=392.83'OUT=392.63'24 " R C P 24 " R C P WOODEDAREA - SR 1775SOUTHWEST TOP OFBANK PROVIDED BYSTEWART SURVEYCOMPLETED ON03.23.2017ZONE 1 AND ZONE 2BUFFER BASED ONESTIMATED NORTHEASTTOP OF BANK20.00' ZONE 2 STREAM BUFFER30.00' ZONE 1 STREAM BUFFER 2 0 . 0 0 '30.00 'PROJECT BOUNDARY40.03 ACRESDATE ISSUEDSHEETJOB NUMBER520 SOUTH HARRINGTON STREET RALEIGH, NC 27601 919.828.2301 919.828.2303 (FAX) OFFICE@HH-ARCH.COM These drawings are the property of HH Architecture, P.A. They may not be used for any purpose without written permission. Copyright 2016 by HH Architecture, P.A. All rights reserved.PROJECT STATUSNORTH CAROLINA AGRICULTURAL SCIENCES CENTER NORTH CAROLINA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES 4600 REEDY CREEK ROAD, RALEIGH NCNCDEQ STORMWATERSCO# 16-14380-02BNO.REVISIONDATEFIRM LICENSE #: C-1051www.stewartinc.comPROJECT #: 16123223 S. WEST ST, SUITE 1100RALEIGH, NC 27603T 919.380.87501COMMENTS11.07.18FOR REVIEW ONLYFF=267.18'SURVEY CONTROL POINTEXISTING IRON PIPEEXISTING CONCRETE MONUMENTSTORM DRAIN MANHOLESANITARY SEWER MANHOLEHYDRANTWATER VALVEWATER METERWATER MANHOLEGAS VALVEGAS METERTELEPHONE MANHOLETELEPHONE PEDESTALTV MANHOLETV PEDESTALELECTRIC MANHOLEELECTRIC BOXUTILITY POLEGUY WIRELIGHT POLETRAFFIC SIGNAL BOXBOLLARDSIGNFINISHED FLOOR ELEVATIONUNDERGROUND TELEPHONE LINEUNDERGROUND FIBER OPTIC LINEUNDERGROUND GAS LINEUNDERGROUND ELECTRIC LINEUNDERGROUND WATER LINESANITARY SEWER LINESTORM DRAIN LINEOVERHEAD WIRESUNIDENTIFIED LINEEIPECMDIPPVCHDPERCPCMPCBTFOGEWSSOHWUDUCTILE IRON PIPEPOLYVINYL CHLORIDE PIPEHIGH-DENSITY POLYETHYLENE PIPEREINFORCED CONCRETE PIPECORRUGATED METAL PIPECATCH BASINCATVTPEDGMWMTRAFFIC SIGNAL POSTGVELECTRIC METERUNKNOWN DESTINATIONFIBER OPTIC WITNESS POSTBORING LOCATIONSTORM DRAIN CURB INLETCOMPUTED POINTFIBER OPTIC BOXGUY POLEMANHOLEDECIDUOUS TREEEVERGREEN TREEBUSHWIRE FENCECHAIN LINK FENCECONCRETE SURFACEWVFOWPEMBORIOLIAMERICAN HOLLYCREPE MYRTLEPOPTQREASTERN SYCAMORELOBLOLLY PINERED OAKEXAMPLE: 10QR = 10" RED OAKMGSOUTHERN MAGNOLIAJVEASTERN RED CEDARSURVEY TREE LEGEND:SURVEY LEGEND:SW1.0EXISTINGLAND USEC1612311.07.20180501002001"= 100'SCALE:NORTHABBREVIATIONS:PROJECT AREA = 40.03 ACEXISTING IMPERVIOUSWITHIN PROJECT AREA =11,250 SF (0.258 AC)EXISTING PROJECT AREA =0.645% IMPERVIOUSPARKINGBUILDING LDLDLD LDLDLDLDLDLDLD LDLDLDLD L D LD LD LD LD LD LDLD LD L D LDLDLDLDLDLD LDLDPI VFDC TPTPTP TP TP TPTPTPTPTPTP TPGVWVWVWVWVWVF F = 4 4 7 . 4 1 '14QR14QR14QR14QR14AR8AR6AR10AR10AR24AR28AR24AR24AR14QR14QR14QR20QR8QR14QR18QR8QR16QR16QR6QR12QR12QR42LS36QA48QA6TREE5TREE5TREE8TREE7TREE40QA40QA30QA30QR8TREE8TREE8TREE40QR22LS8QP4PY5PY4QR36QA40QA40QA34QAEDWARDS MILL ROADSR 3009VARIABLE WIDTH PUBLIC R/WREEDY CREEK ROADVARIABLE WIDTH PUBLIC R/WREEDY CREEK ROADVARIABLE WIDTH PUBLIC R/WWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAGIS ZONING LINE"AP""OX-3"GIS ZONING LINE"AP""OX-3"15"RCP15"RCP 8"PVC4"PVC8"PVC8"PVC 8" P V C 15"RCP24"RCP24"RCP24"RCPTOC=434.52'IN=429.32'OUT=429.12'15"RCPTOC=408.90'OUT=404.70'15"RCPTOC=399.70'IN(15")=394.10'IN(18")=394.20'OUT=393.95'TOC=400.42'OUT=395.82'18 " R C PTOC=408.12'IN=403.12'OUT=402.72'GWPTOC=446.46'OUT=441.31'15"RCPTOC=441.89'IN=432.89'OUT=432.29'INV=429.62'24 " R C P INV=433.29'TOC=442.72'OUT=437.77'TOC=444.89'IN(4")=441.29'IN(15")=437.09'OUT=436.89'INV=435.98'RIM=444.83'IN(4")=439.43'IN(8")=440.15'IN(15")=437.93'OUT=437.73'RIM=444.98'IN=439.18'IN=439.18'OUT=438.88'SIGNTPEDRWMEIREIREIPRWMS49°11'35"W 585.30'N60°48'20"W 169.00'N09°54'07"W 120.90'N32°32'49"E 57.90' N 3 2 ° 2 9 ' 2 3 " EC1C2L1L2 N50°51'53"WRWMASPHALT SIGNGATEEE E 15"RCPASPHALTPARKINGASPHALTPARKING4' WIREFENCE4' WIREFENCE8"PVC15"RCP8"PVC8"PVCRIM=391.78'IN=381.48'OUT=381.46'RIM=391.93'IN=384.93'OUT=383.07'S60°48'20"E76.65'TPEDN50°51'53"W15"RCPTOC=398.48'OUT=394.38'TOC=398.47'IN=394.37'OUT=394.17'TOC=397.93'IN(15")=392.83'IN(24")=392.83'OUT=392.63'24 " R C P 24 " R C P WOODEDAREA - SR 1775SOUTHWEST TOP OFBANK PROVIDED BYSTEWART SURVEYCOMPLETED ON03.23.2017ZONE 1 AND ZONE 2BUFFER BASED ONESTIMATED NORTHEASTTOP OF BANK20.00' ZONE 2 STREAM BUFFER30.00' ZONE 1 STREAM BUFFER 2 0 . 0 0 '30.00 'PROJECT BOUNDARY40.12 ACRESDATE ISSUEDSHEETJOB NUMBER520 SOUTH HARRINGTON STREET RALEIGH, NC 27601 919.828.2301 919.828.2303 (FAX) OFFICE@HH-ARCH.COM These drawings are the property of HH Architecture, P.A. They may not be used for any purpose without written permission. Copyright 2016 by HH Architecture, P.A. All rights reserved.PROJECT STATUSNORTH CAROLINA AGRICULTURAL SCIENCES CENTER NORTH CAROLINA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES 4600 REEDY CREEK ROAD, RALEIGH NCNCDEQ STORMWATERSCO# 16-14380-02BNO.REVISIONDATEFIRM LICENSE #: C-1051www.stewartinc.comPROJECT #: 16123223 S. WEST ST, SUITE 1100RALEIGH, NC 27603T 919.380.87501COMMENTS11.07.18FOR REVIEW ONLYFF=267.18'SURVEY CONTROL POINTEXISTING IRON PIPEEXISTING CONCRETE MONUMENTSTORM DRAIN MANHOLESANITARY SEWER MANHOLEHYDRANTWATER VALVEWATER METERWATER MANHOLEGAS VALVEGAS METERTELEPHONE MANHOLETELEPHONE PEDESTALTV MANHOLETV PEDESTALELECTRIC MANHOLEELECTRIC BOXUTILITY POLEGUY WIRELIGHT POLETRAFFIC SIGNAL BOXBOLLARDSIGNFINISHED FLOOR ELEVATIONUNDERGROUND TELEPHONE LINEUNDERGROUND FIBER OPTIC LINEUNDERGROUND GAS LINEUNDERGROUND ELECTRIC LINEUNDERGROUND WATER LINESANITARY SEWER LINESTORM DRAIN LINEOVERHEAD WIRESUNIDENTIFIED LINEEIPECMDIPPVCHDPERCPCMPCBTFOGEWSSOHWUDUCTILE IRON PIPEPOLYVINYL CHLORIDE PIPEHIGH-DENSITY POLYETHYLENE PIPEREINFORCED CONCRETE PIPECORRUGATED METAL PIPECATCH BASINCATVTPEDGMWMTRAFFIC SIGNAL POSTGVELECTRIC METERUNKNOWN DESTINATIONFIBER OPTIC WITNESS POSTBORING LOCATIONSTORM DRAIN CURB INLETCOMPUTED POINTFIBER OPTIC BOXGUY POLEMANHOLEDECIDUOUS TREEEVERGREEN TREEBUSHWIRE FENCECHAIN LINK FENCECONCRETE SURFACEWVFOWPEMBORIOLIAMERICAN HOLLYCREPE MYRTLEPOPTQREASTERN SYCAMORELOBLOLLY PINERED OAKEXAMPLE: 10QR = 10" RED OAKMGSOUTHERN MAGNOLIAJVEASTERN RED CEDARSURVEY TREE LEGEND:SURVEY LEGEND:SW2.0PROPOSEDLAND USEC1612311.07.20180501002001"= 100'SCALE:NORTHABBREVIATIONS:PROJECT AREA = 40.12 ACPROPOSED IMPERVIOUSWITHIN PROJECT AREA =320,603 SF (7.36 AC)PROPOSED PROJECT AREA= 18.29% IMPERVIOUSSIDEWALK/ WALLSROADPARKINGBUILDING GVWVWVWVWVWVF F = 4 4 7 . 4 1 ' FF=438.26'FF=433.76'FF=436.90'14QR14QR14QR14QR14AR10AR10AR8AR12AR8AR6AR10AR10AR24AR28AR24AR24AR14QR14QR14QR20QR8QR14QR18QR8QR16QR16QR24QR12QR6QR12QR12QR16QR42LS36QA48QA5PY5PY6PT9PT3CF4PY4LS6LS7PT3PY3PY6TREE5TREE5TREE8TREE7TREE40QA40QA30QA30QR8TREE8TREE8TREE40QR4JV3AR7TREE5TREE7TREE22LS8QP26LS15LS4PY5PY4QRVAULT36QA40QA12JV40QA34QAGATE GATEGATEGATEGA T E GATECONTROL POINTN:751803.84'E:2085432.48'EL:428.28'EDWARDS MILL ROADSR 3009VARIABLE WIDTH PUBLIC R/WREEDY CREEK ROADVARIABLE WIDTH PUBLIC R/WREEDY CREEK ROADVARIABLE WIDTH PUBLIC R/WWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAGIS ZONING LINE"AP""OX-3"GIS ZONING LINE"AP""OX-3"15"RCP15"RCP15"RCP8"PVC4"PVC8"PVC8"PV C 8" P V C 15"RCP24"RCP24"RCP24"RCPTOC=434.52'IN=429.32'OUT=429.12'TOC=435.19'IN=428.89'OUT=428.69'15"RCPTOC=408.90'OUT=404.70'INV=420.14'18 " R C PTOC=408.12'IN=403.12'OUT=402.72'GWPGATETOC=446.46'OUT=441.31'15"RCPTOC=441.89'IN=432.89'OUT=432.29'INV=429.62'24 " R C P INV=433.29'INV=436.90'TOC=442.72'OUT=437.77'TOC=444.89'IN(4")=441.29'IN(15")=437.09'OUT=436.89'INV=435.98'RIM=444.83'IN(4")=439.43'IN(8")=440.15'IN(15")=437.93'OUT=437.73'RIM=444.98'IN=439.18'IN=439.18'OUT=438.88'SIGNSIGNTPEDGRAVELRWMEIREIRRWMS49°11'35"W 585.30'N60°48'20"W 169.00'N09°54'07"W 120.90'N32°32'49"E 57.90' N 3 2 ° 2 9 ' 2 3 " EC1C2L1L2 N50°51'53"WRWMASPHALT SIGNGATEEE E 15"RCPASPHALTPARKINGASPHALTPARKINGASPHALTPARKINGRIPRAPFEEDERPADFEEDERPAD4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCE4' WIREFENCESPIGOTS60°48'20"E76.65'TPEDN50°51'53"WTIMBER TIMBER WOODEDAREA - SR 1775SOUTHWEST TOP OFBANK PROVIDED BYSTEWART SURVEYCOMPLETED ON03.23.2017ZONE 1 AND ZONE 2BUFFER BASED ONESTIMATED NORTHEASTTOP OF BANK20.00' ZONE 2 STREAM BUFFER30.00' ZONE 1 STREAM BUFFER 2 0 . 0 0 '30.00 ' DD DD DD DD DD DDDDDDDDDDDDDDDDDDDDDDDDDDD D D DDDDD DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD DD D D DD DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD DD DD DD DD DD DD NORTH ANALYSIS POINTEXISTING VEGETATED CONVEYANCEEAST ANALYSIS POINTSOUTH ANALYSIS POINTOFF-SITE DRAINAGED D DD DD TIME OF CONCENTRATIONFLOW PATHDDDDDDDDDDDDDDTIME OF CONCENTRATIONFLOW PATHDDDDDDDDTIME OFCONCENTRATIONFLOW PATHDATE ISSUEDSHEETJOB NUMBER520 SOUTH HARRINGTON STREET RALEIGH, NC 27601 919.828.2301 919.828.2303 (FAX) OFFICE@HH-ARCH.COM These drawings are the property of HH Architecture, P.A. They may not be used for any purpose without written permission. Copyright 2016 by HH Architecture, P.A. All rights reserved.PROJECT STATUSNORTH CAROLINA AGRICULTURAL SCIENCES CENTER NORTH CAROLINA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES 4600 REEDY CREEK ROAD, RALEIGH NCNCDEQ STORMWATERSCO# 16-14380-02BNO.REVISIONDATEFIRM LICENSE #: C-1051www.stewartinc.comPROJECT #: 16123223 S. WEST ST, SUITE 1100RALEIGH, NC 27603T 919.380.87501COMMENTS11.07.18FOR REVIEW ONLYFF=267.18'SURVEY CONTROL POINTEXISTING IRON PIPEEXISTING CONCRETE MONUMENTSTORM DRAIN MANHOLESANITARY SEWER MANHOLEHYDRANTWATER VALVEWATER METERWATER MANHOLEGAS VALVEGAS METERTELEPHONE MANHOLETELEPHONE PEDESTALTV MANHOLETV PEDESTALELECTRIC MANHOLEELECTRIC BOXUTILITY POLEGUY WIRELIGHT POLETRAFFIC SIGNAL BOXBOLLARDSIGNFINISHED FLOOR ELEVATIONUNDERGROUND TELEPHONE LINEUNDERGROUND FIBER OPTIC LINEUNDERGROUND GAS LINEUNDERGROUND ELECTRIC LINEUNDERGROUND WATER LINESANITARY SEWER LINESTORM DRAIN LINEOVERHEAD WIRESUNIDENTIFIED LINEEIPECMDIPPVCHDPERCPCMPCBTFOGEWSSOHWUDUCTILE IRON PIPEPOLYVINYL CHLORIDE PIPEHIGH-DENSITY POLYETHYLENE PIPEREINFORCED CONCRETE PIPECORRUGATED METAL PIPECATCH BASINCATVTPEDGMWMTRAFFIC SIGNAL POSTGVELECTRIC METERUNKNOWN DESTINATIONFIBER OPTIC WITNESS POSTBORING LOCATIONSTORM DRAIN CURB INLETCOMPUTED POINTFIBER OPTIC BOXGUY POLEMANHOLEDECIDUOUS TREEEVERGREEN TREEBUSHWIRE FENCECHAIN LINK FENCECONCRETE SURFACEWVFOWPEMBORIOLIAMERICAN HOLLYCREPE MYRTLEPOPTQREASTERN SYCAMORELOBLOLLY PINERED OAKEXAMPLE: 10QR = 10" RED OAKMGSOUTHERN MAGNOLIAJVEASTERN RED CEDARSURVEY TREE LEGEND:SURVEY LEGEND:SW3.0EXISTINGDRAINAGE AREAC1612311.07.2018030601201"= 60'SCALE:NORTHABBREVIATIONS:NORTH DRAINAGE AREA12.315 ACEAST DRAINAGE AREA4.130 ACSOUTH DRAINAGE AREA3.786 ACIMPERVIOUS AREA LDLDLDLDLD LDLDLDLDLDLDLDLDLD LDLDLDLDLDLDLDL D LD L D LDLDLD LD LD LD LDLD LD LDLDLDLD LD LD L D LDLDLDLDLDLDLD LDLD PIVFDC TPTPTPTPTP TPTP TP TP TP TPTP T P TPTPTPTPTPTPTPTP TPTPGVWVWVWVWVWVF F = 4 4 7 . 4 1 '14QR14QR14QR14QR14AR8AR6AR10AR10AR24AR28AR24AR24AR14QR14QR14QR20QR8QR14QR18QR8QR16QR16QR6QR12QR12QR42LS36QA48QA6TREE5TREE5TREE8TREE7TREE40QA40QA30QA30QR8TREE8TREE8TREE40QR22LS8QP4PY5PY4QR36QA40QA40QA34QAEDWARDS MILL ROADSR 3009VARIABLE WIDTH PUBLIC R/WREEDY CREEK ROADVARIABLE WIDTH PUBLIC R/WREEDY CREEK ROADVARIABLE WIDTH PUBLIC R/WWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAWOODEDAREAGIS ZONING LINE"AP""OX-3"GIS ZONING LINE"AP""OX-3"15"RCP15"RCP 8"PVC4"PVC8"PVC8"PV C 8" P V C 15"RCP24"RCP24"RCP24"RCPTOC=434.52'IN=429.32'OUT=429.12'15"RCPTOC=408.90'OUT=404.70'18 " R C PTOC=408.12'IN=403.12'OUT=402.72'GWPTOC=446.46'OUT=441.31'15"RCPTOC=441.89'IN=432.89'OUT=432.29'INV=429.62'24 " R C P INV=433.29'TOC=442.72'OUT=437.77'TOC=444.89'IN(4")=441.29'IN(15")=437.09'OUT=436.89'INV=435.98'RIM=444.83'IN(4")=439.43'IN(8")=440.15'IN(15")=437.93'OUT=437.73'RIM=444.98'IN=439.18'IN=439.18'OUT=438.88'SIGNTPEDRWMEIREIRRWMS49°11'35"W 585.30'N60°48'20"W 169.00'N09°54'07"W 120.90'N32°32'49"E 57.90' N 3 2 ° 2 9 ' 2 3 " EC1C2L1L2 N50°51'53"WRWMASPHALT SIGNGATEEE E 15"RCPASPHALTPARKINGASPHALTPARKING4' WIREFENCE4' WIREFENCES60°48'20"E76.65'TPEDN50°51'53"WWOODEDAREA - SR 1775SOUTHWEST TOP OFBANK PROVIDED BYSTEWART SURVEYCOMPLETED ON03.23.2017ZONE 1 AND ZONE 2BUFFER BASED ONESTIMATED NORTHEASTTOP OF BANK20.00' ZONE 2 STREAM BUFFER30.00' ZONE 1 STREAM BUFFER 2 0 . 0 0 '30.00 'NORTH ANALYSIS POINTEXISTING VEGETATED CONVEYANCEEAST ANALYSIS POINTSOUTH ANALYSIS POINTOFF-SITE DRAINAGE425426 4254234244274454454454434444444444 4 5 4 4 4 DATE ISSUEDSHEETJOB NUMBER520 SOUTH HARRINGTON STREET RALEIGH, NC 27601 919.828.2301 919.828.2303 (FAX) OFFICE@HH-ARCH.COM These drawings are the property of HH Architecture, P.A. They may not be used for any purpose without written permission. Copyright 2016 by HH Architecture, P.A. All rights reserved.PROJECT STATUSNORTH CAROLINA AGRICULTURAL SCIENCES CENTER NORTH CAROLINA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES 4600 REEDY CREEK ROAD, RALEIGH NCNCDEQ STORMWATERSCO# 16-14380-02BNO.REVISIONDATEFIRM LICENSE #: C-1051www.stewartinc.comPROJECT #: 16123223 S. WEST ST, SUITE 1100RALEIGH, NC 27603T 919.380.87501COMMENTS11.07.18FOR REVIEW ONLYFF=267.18'SURVEY CONTROL POINTEXISTING IRON PIPEEXISTING CONCRETE MONUMENTSTORM DRAIN MANHOLESANITARY SEWER MANHOLEHYDRANTWATER VALVEWATER METERWATER MANHOLEGAS VALVEGAS METERTELEPHONE MANHOLETELEPHONE PEDESTALTV MANHOLETV PEDESTALELECTRIC MANHOLEELECTRIC BOXUTILITY POLEGUY WIRELIGHT POLETRAFFIC SIGNAL BOXBOLLARDSIGNFINISHED FLOOR ELEVATIONUNDERGROUND TELEPHONE LINEUNDERGROUND FIBER OPTIC LINEUNDERGROUND GAS LINEUNDERGROUND ELECTRIC LINEUNDERGROUND WATER LINESANITARY SEWER LINESTORM DRAIN LINEOVERHEAD WIRESUNIDENTIFIED LINEEIPECMDIPPVCHDPERCPCMPCBTFOGEWSSOHWUDUCTILE IRON PIPEPOLYVINYL CHLORIDE PIPEHIGH-DENSITY POLYETHYLENE PIPEREINFORCED CONCRETE PIPECORRUGATED METAL PIPECATCH BASINCATVTPEDGMWMTRAFFIC SIGNAL POSTGVELECTRIC METERUNKNOWN DESTINATIONFIBER OPTIC WITNESS POSTBORING LOCATIONSTORM DRAIN CURB INLETCOMPUTED POINTFIBER OPTIC BOXGUY POLEMANHOLEDECIDUOUS TREEEVERGREEN TREEBUSHWIRE FENCECHAIN LINK FENCECONCRETE SURFACEWVFOWPEMBORIOLIAMERICAN HOLLYCREPE MYRTLEPOPTQREASTERN SYCAMORELOBLOLLY PINERED OAKEXAMPLE: 10QR = 10" RED OAKMGSOUTHERN MAGNOLIAJVEASTERN RED CEDARSURVEY TREE LEGEND:SURVEY LEGEND:SW4.0PROPOSEDDRAINAGE AREAC1612311.07.2018030601201"= 60'SCALE:NORTHABBREVIATIONS:NORTH DRAINAGE AREA14.128 ACEAST DRAINAGE AREA1.664 ACSOUTH DRAINAGE AREA5.425 ACIMPERVIOUS AREA Appendix 7 Seasonally High Water Table Report Ecological Engineering, LLP Project No. 10502-197 Page 1 of 2 1151 SE Cary Parkway, Suite 101 Cary, North Carolina 27518 (919) 557-0929 www.ecologicaleng.com July 4, 2017 Ms. Jennifer Wagner, PLA, ASLA, LEEP AP Stewart, Inc. 421 Fayetteville Street, Suite 400 Raleigh, NC 27601 Re: Seasonal High Water Table (SHWT) Evaluation NC Agricultural Center Raleigh, Wake County, NC Ms. Wagner: Ecological Engineering, LLP (Ecological Engineering) appreciates the opportunity to provide this Seasonal High Water Table (SHWT) evaluation with regard to the proposed BMPs at the abovementioned site. The project site is situated near at the intersection of Edwards Mill Rd. and Reedy Creek Rd. in Raleigh (Figure 1). Ecological Engineering utilized information provided by Stewart, to locate the soil borings for the SHWT determination. Two areas were hand-augered to review and determine the SHWT. Assessments were conducted by Heather Smith, LSS, on July 4, 2017. The following information summarizes the results of our evaluation. Existing Conditions and Area of Evaluation The current landuse surrounding Hole # 1 is a maintained lawn with clover and fescue and Hole # 2 is an active cattle pasture. The holes were dug within the footprints of the proposed BMPs (Figure 2). According to the Soil Survey of Wake County, NC (Cawthorn, 1970) and current data on the USDA Web Soil Survey, the underlying soil at Hole #1 is Appling sandy loam with 2 to 6 percent slopes and the soil at Hole # 2 is Cecil gravelly sandy loam with 6 to 10 percent slopes. These soils are well drained with a subsoil of clay with moderate permeability. Appling and Cecil soils have moderate to rapid runoff. These soil series occur on ridges and side slopes in uplands within the Piedmont of North Carolina. Results The following information describes the soils encountered at the boring location. Our assessments followed and were consistent with Rule 1942 (NCAC.2004) which states “a soil wetness condition shall be determined by the indication of colors of chroma 2 or less (Munsell Color Charts) at > 2% of soil volume or a soil wetness condition shall also be determined by periodic direct observation or indication of saturated soils or a perched water table, or lateral water movement flowing into a bore hole monitoring well, or open excavation above a less permeable horizon or horizon subdivision that may occur without the presence of colors of chroma 2 or less”. Please be advised the auger method for visual field assessment by soil color can be an inaccurate assessment of the actual SHWT. The percentage of SHWT indicators is difficult to determine. The use of a pit provides a greater degree of accuracy. 0 1,000 2,000500 Feet ³2013 USGS Quadrangle Raleigh West Figure 1Seasonal High Water Table DeterminationVicinty MapNC Agricultural CenterWake County, NCJuly 2017 Prepared By:Prepared For: Project Location 0 300 600150 Feet ³ Legend Proposed BMP 2013 NC Onemap Aerials Figure 2Seasonal High Water Table DeterminationBoring LocationsNC Agricultural CenterWake County, NCJuly 2017 Prepared By:Prepared For: Hole # 2 Hole # 1Edwards Mill Rd.Reed y C r e e k R d .