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Home My WebLink AboutSW6240107_Stormwater Report_20240205 RAEFORD SOUTH 115KV SUBSTATION REBUILD HOKE COUNTY RAEFORD, NORTH CAROLINA POST-CONSTRUCTION STORMWATER REPORT PROJECT NUMBER: DKE-23021 DESIGNED BY: ALEC MILLS CHECKED BY: DATE: DECEMBER 15, 2023 1 1 McADAMS 621 HILLSBOROUGH STREET, SUITE 500 RALEIGH, NORTH CAROLINA 27603 NC LIC. # C-0293 RAEFORD SOUTH 115KV SUBSTATION REBUILD HOKE COUNTY RAEFORD, NORTH CAROLINA POST-CONSTRUCTION STORMWATER REPORT SECTION I 1.0 PROJECT DESCRIPTION The Duke Energy Substation for this project is located at 1600 Oakdale Gin Road in Raeford, NC. The existing substation is to be removed with an enlarged substation to be built in its place. A mobile substation and temporary transmission line with be used during construction. The proposed substation expansion shall be subject to erosion control management requirements set forth by the North Carolina Department of Environmental Quality (NCDEQ). Total site disturbed area is 3.45 acres. The site is flat, and slightly draining towards the center of the site, with the exception of the western corner of the site that drains to the west at about 2.5%. Outside of the existing substation, substation shoulder, and transmission line right-of-way, the site is wooded with pines. The soil is sandy and in the hydrologic soil group A. There are no significant ditches or concentrated flows on the site. The project area lies in a slight basin without significant drainage leaving the site, with A soils causing high infiltration. There are no ditches along the road and no culverts under the existing substation drive or the road. 2.0 BUIT-UPON AREA The proposed use of the site is an expansion of the electrical substation. The typical section of the gravel to comprise the substation yard is included in the construction drawings and consists, from bottom to top, of a three-inch compacted ABC subgrade, a three-inch lift of ABC, and a three-inch lift of washed#57 stone. The gravel yard within the fence will receive very infrequent vehicular traffic. According to the North Carolina Division of Environmental Quality's (NCDEQ) Minimum Design Criteria, and direction from NCDEQ staff on implementation of the built-upon area (BUA) requirements, the gravel yard within the fence is not considered BUA for either the pre-project or post-project scenarios. Post-Construction Stormwater Report 1 McAdams Raeford South 115kV—Rebuild 12/15/2023 Raeford,Hoke County,North Carolina Drainge from the substation pad will be via sheet flow, with no ditches or storm piping proposed. The site's hydrologic soil group A soils will infiltrate stormwater effectively. Post-Construction Stormwater Report 2 McAdams Raeford South 115kV—Rebuild 12/15/2023 Raeford,Hoke County,North Carolina LIST OF APPENDICES • PRECIPITATION FREQUENCY DATA TABLES • DRAINAGE AREA MAP • AERIAL AND TOPO MAPS • NRCS HISTORICAL SOIL REPORT MAP • NRCS HYDROLOGIC SOIL GROuP MAP Post-Construction Stormwater Report 3 McAdams Raeford South I I5kV—Rebuild 12/15/2023 Raeford,Hoke County,North Carolina Precipitation Frequency Data Tables Post-Construction Stormwater Report 4 McAdams Raeford South 115kV—Rebuild 12/15/2023 Raeford,Hoke County,North Carolina 10/31/23,9:46AM Precipitation Frequency Data Server 9 NOAA Atlas 14,Volume 2,Version 3 Location name: Raeford,North Carolina,USA* � '`� Latitude:34.9602°, Longitude: -79.2111° Elevation:248 ft** 0 *source:ESRI Maps �M^ y� **source:USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M.Bonnin,D.Martin,B.Lin,T.Parzybok,M.Yekta,and D.Riley NOAA,National Weather Service,Silver Spring,Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1 Average recurrence interval(years) Duration� 2 � 10 25 50 100 200 500 1000 5-min 5.22 6.16 -719-7F 7.97 8.90 9.58 10.2 10.8 11.6 12.2 (4.75-5.76) 1 (5.62-6.80) (6.55-7.94) (7.24-8.77) (8.05-9.78) (8.64-10.5) (9.17-11.2) (9.67-11.9) (10.2-12.7) (10.7-13.4) 10-min 4.17 4.93 5.76 6.37 7.09 7.63 8.12 8.59 9.17 9.59 (3.80-4.60) 1 (4.49-5.44) 11 (5.24-6.35) (5.79-7.01) (6.41-7.79) (6.88-8.36) (7.28-8.90) (7.66-9.41) (8.11-10.0) (8.43-10.5) 15-min 3.48 4.13 4.86 5.38 5.99 6.44 .02 6.85 7.22 7.69 8 (3.17-3.84) 1 (3.77-4.56) 11 (4.42-5.36) 1 (4.88-5.92) 1 (5.42-6.58) 1 (5.80-7.06) (6.14-7.50) (6.45-7.91) (6.80-8.43) (7.05-8.80) 30-min 2.38 2.85 3.45 3.89 4.44 4.85 5.24 5.62 6.12 6.50 (2.17-2.63) 1 (2.60-3.15) 1 (3.14-3.81) (3.54-4.29) (4.01-4.88) 1 (4.37-5.32) (4.70-5.75) (5.02-6.16) (5.41-6.71) (5.71-7.13) 60-min 1.49 1.79 2.21 2.54 2.96 3.28 3.61 3.94 4.39 4.74 (1.35-1.64) (1.63-1.98) (2.01-2.44) (2.30-2.79) (2.67-3.25) (2.96-3.60) (3.24-3.96) (3.52-4.32) (3.88-4.81) (4.17-5.20) 2-hr 0.865 1.05 1.32 1.53 1.81 2.03 2.26 2.49 2.81 3.06 (0.782-0.968) (0.948-1.17) 1 (1.19-1.47) 1 (1.38-1.70) 1 (1.62-2.02) (1.81-2.26) (2.00-2.52) (2.20-2.77) (2.45-3.12) (2.65-3.40) 3-hr 0.609 0.738 0.933 1.09 1.30 1.48 1.67 1.86 2.14 2.36 (0.551-0.684) (0.667-0.828) (0.841-1.04) (0.979-1.22) 1 (1.16-1.46) 1 (1.32-1.65) (1.47-1.86) 1 (1.63-2.07) (1.84-2.38) (2.02-2.62) 6-hr 0.364 0.441 0.558 0.652 0.784 0.893 1.01 1.13 1.30 1.44 (0.330-0.406) (0.400-0.491) (0.505-0.619) (0.588-0.723) (0.702-0.868) (0.794-0.986) (0.889-1.11) (0.987-1.24) 1 (1.12-1.43) 1 (1.23-1.58) 12-hr 0.213 0.258 IF 0.328 0.386 0.467 0.535 0.607 0.685 0.797 0.890 (0.192-0.238) (0.233-0.288) (0.296-0.365) (0.346-0.429) (0.416-0.517) (0.473-0.591) (0.532-0.670) (0.594-0.755) (0.681-0.879) (0.750-0.979) 24-hr 0.126 0.153 0.194 0.226 0.271 0.307 0.345 0.384 0.437 0.4 99 (0.117-0.136) (0.142-0.165) (0.179-0.209) (0.209-0.244) (0.250-0.292) (0.282-0.331) (0.315-0.372) (0.350-0.413) (0.397-0.471) (0.433-0.517) 2-day 0.073 0.088 0.111 0.129 0.154 0.174 0.195 0.216 0.246 0.269 (0.068-0.078) (0.082-0.095) (0.103-0.119) (0.120-0.139) (0.142-0.165) (0.160-0.187) (0.179-0.209) (0.198-0.232) (0.223-0.264) (0.244-0.290) 3-day 0.051 0.062 0.078 0.090 0.107 0.121 0.135 0.150 0.170 0.186 (0.048-0.055) (0.058-0.067) (0.073-0.083) (0.084-0.097) (0.100-0.115) (0.112-0.130) (0.125-0.145) (0.138-0.161) (0.155-0.182) (0.169-0.200) 4-day 0.041 0.049 0.061 0.071 0.084 0.095 0.106 0.117 0.13 2 0.144 (0.038-0.044) (0.046-0.053) (0.057-0.065) (0.066-0.076) (0.078-0.090) (0.088-0.101) (0.098-0.113) (0.108-0.125) (0.121-0.142) (0.132-0.155) 7-day 0.027 0.032 0.040 0.046 0.054 0.060 0.067 0.074 0.083 0.091 (0.025-0.029) (0.030-0.035) (0.037-0.043) (0.043-0.049) (0.050-0.058) (0.056-0.065) (0.062-0.072) (0.068-0.079) (0.077-0.089) (0.083-0.098) 10-day 0.021 0.026 0.031 0.036 0.041 0.046 0.051 0.055 0.062 0.067 (0.020-0.023) (0.024-0.027) (0.029-0.033) (0.033-0.038) (0.039-0.044) (0.043-0.049) (0.047-0.054) (0.051-0.059) (0.057-0.066) (0.061-0.071) 20-day 0.014 0.017 0.020 0.023 0.027 0.029 0.032 0.035 0.039 0.042 (0.014-0.015) (0.016-0.018) (0.019-0.022) (0.022-0.024) (0.025-0.028) (0.027-0.031) (0.030-0.034) (0.033-0.037) (0.036-0.041) (0.039-0.044) 30-day 0.012 0.014 0.016 0.018 0.021 0.023 0.025 0.027 0.029 0.031 (0.011-0.012) (0.013-0.015) (0.016-0.017) (0.017-0.019) (0.020-0.022) (0.021-0.024) (0.023-0.026) (0.025-0.028) (0.027-0.031) (0.029-0.033) 45-day 0.010 0.012 0.013 0.015 0.017 0.018 0.019 0.021 0.022 0.024 (0.009-0.010) (0.011-0.012) (0.013-0.014) (0.014-0.016) (0.016-0.018) (0.017-0.019) (0.018-0.021) (0.019-0.022) (0.021-0.024) (0.022-0.025) 60-day 0.009 0.010 0.012 0.013 0.015 0.016 ( 0.017 0.018 0.019 0.020 (0 08 ) .0 -0.009) (0.010-0.011) (0.011-0.013) (0.012-0.014) (0.014-0 ) (0.015 .015-0.017) 0.016-0.018) (0.017-0.019) (0.018-0.020) (0.019-0.021 t Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates(for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical https://hdse.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.9602&Ion=-79.2111&data=intensity&units=engIish&series=pds 1/4 10/31/23,9:46AM Precipitation Frequency Data Server PDS-based intensity-duration-frequency (IDF) curves Latitude: 34.96021. Longitude: -79.21111 Average recurrence 101 interval i {years} L C t 10n — d — 10 e — 25 G 50 4� 10-1 — 100 — 200 — 500 o. 1000 10-z 17N r = = s sfu E E E E E r� r� -Y -Y� � ry ri� A A LAram, Duration,1 N o N rn rn -;1-0 101 r k c Duration c — 5-min — 2-day a, � — 10-min — 3-day 15-min — 4-day — 3 -min — 7-day .49 10-1 — 54-min — 10 day EL — 2fir — 2d-day a — 34nr — 3"ay — 6fir — 4-day 10-2 — 12-nr — 60-day 24^hr 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval (years) NOAAAtlas 14,volume 2,Versian 3 Created(GMT}_TueOct 31 13:46.26 2023 Back to Top Maps & aerials Small scale terrain https://hdse.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.9602&Ion=-79.2111&data=intensity&units=engIish&series=pds 2/4 10/31/23,9:46AM Precipitation Frequency Data Server R ae��fo rcl Ti,sA4 ys+ 3km Dunclarracli ` 2mi Large scale terrain Winston-Sal en, Greensboro Rocky Mount Raleigh NORTH CAROLINA Greei Charlotte Fayettjwill, � IJackso T H C A R O L I N A Wilmington + }o ■ _ aY 1■001Km 60mi Large scale map iriston� lem Green�l,€:ia durhani Rocky Mount :Raleigh North Greem Carolina arlotte I F etteville -- I Jackso 0 Wi€mi jn-him 100km 60mi Large scale aerial https://hdse.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.9602&Ion=-79.2111&data=intensity&units=engIish&series=pds 3/4 10/31/23,9:46AM Precipitation Frequency Data Server Rocky mourfL ## # Durham Ralagh NOFth Ciarolinia ChIllotte acksor [IT11 A 100km 60mi Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring,MD 20910 Questions?:HDSC.Questions@_noaa.gov Disclaimer https:Hhdse.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.9602&Ion=-79.2111&data=intensity&units=engIish&series=pds 4/4 Drainage Area Map Post-Construction Stormwater Report 5 McAdams Raeford South 115kV—Rebuild 12/15/2023 Raeford,Hoke County,North Carolina DRAINAGE AREAS LEGEND •II11111II. SILT FENCE OUTLET —SF—SF—SF— SILT FENCE —W—W—W— TREE PROTECTION FENCE —LD—LD— LIMITS OF DISTURBANCE \J�MMI�J TREE LINE PROPERTY LINE RIGHT—OF—WAY LINE DRAINAGE AREA DELINIATION —242 1 0"*_� mum , �� 1 ■ ti� s � i\ t ,WAY � 4 ■ 2.13 AC. ♦ •� � 2.04 AC. i � I • , 1 I I - ;�� ♦ r. 10 ♦ IWO_IV z46 — o. I --- ',zso�s OAKDALE GIN ROAD(SR1403) — E L s The John R.McAdams Company,Inc. p C RO4 621 Hillsborough Street ,.��N CAR°° DUKE RaleightNC27603 °''=°a��ss'°�9�'`- �N SEAL ENERGY® phone 919.361.6000 034365 faz919.361,2269 ��. PROGRESS L license number:C-0293,C-187 TTTTT�� MCADAMS "K��` ��,: 9. www.mcadamsco.com ,err' ' 'rs, RAEFORD SOUTH 115kV SUBSTATION REBUILD g PRELIMINARY DRAWING - ISSUED FOR PERMITTING DRAINAGE AREAS - PRE CONSTRUCTION LocATON RAEFORD, NC GRAPHIC SCALE SCALE AS NOTED SCALE RATIO 1:1 DRAWN ADM CHK. PLC APP. — 3 urn=30m. NO. DATE REVISION BY CK. APP. DATE 1/2/2024 DWG.No.82547 SHEET 5 OF 19 30 ft� NO. DAT[ REVISION BY �� DRAINAGE AREAS LEGEND •II11111II- SILT FENCE OUTLET —SF—SF—SF— SILT FENCE —W—W—W— TREE PROTECTION FENCE —LD—LD— LIMITS OF DISTURBANCE \J�MMI�J TREE LINE PROPERTY LINE RIGHT—OF—WAY LINE DRAINAGE AREA DELINIATION —242 - = t . \ t I � N 2.78 AC. � 1.39 AC � i I f I I ` /�aa OAKDALE GIN ROAD(SR1403) i s s The John R.McAdams Company,Inc. p C RO 621 Hillsborough Street ••o`��N CAR°? DUKE RaleightNC27603 °'•=°'KSs'° 9�'`- ENERGY® N SEAL phone 919.361.6000 034365 faz919.361,2269 ��. PROGRESS L license number:C-0293,C-187 TTTTT�� MCADAMS "K�� •••••: 9. www.mcadamsco.com ,err' ' 'rs, RAEFORD SOUTH 115kV SUBSTATION REBUILD g PRELIMINARY DRAWING — ISSUED FOR PERMITTING DRAINAGE AREAS— POST CONSTRUCTION LocATON RAEFORD, NC GRAPHIC SCALE SCALE AS NOTED SCALE RATIO 1:1 DRAWN ADM CHK. PLC APP. _ 3 urn=30fn. NO. DATE REVISION BY CK. APP. DATE 1/2/2024 DWG.No.82547 SHEET 5 OF 19 30 ft� NO. DATI REVISION BY �� Aerial and Topo Maps Post-Construction Stormwater Report 6 McAdams Raeford South 115kV—Rebuild 12/15/2023 Raeford,Hoke County,North Carolina r. Yy•, F #R _� � ''ky{ tir*�.� .7} �1. � � _•rye;,. 4r�tf,C • ' ' �+r.:'. of .- y r ; R .. y t t Of 40 1 - • - . SOUTH 115KV SUB REBUILD SITE AERIAL MAP 00 Me 8 -------------- IN ®r I a `m 6, - �� _ IINll�llllllp r e Eon mom ® nun NRCS Historical Soil Report Map Post-Construction Stormwater Report 7 McAdams Raeford South 115kV—Rebuild 12/15/2023 Raeford,Hoke County,North Carolina � �..�� a •�. � � � �,, `fir _ D ® � , NRCS Hydrologic Soil Group Map Post-Construction Stormwater Report 8 McAdams Raeford South 115kV—Rebuild 12/15/2023 Raeford,Hoke County,North Carolina 3 Hydrologic Soil Group—Hoke County,North Carolina 3 M (Hydrologic Soils Group) 6628DD 66M 663000 663100 663200 663MD 663400 663500 663600 663700 663WD 34°57 47'N _ _ -- 34'57'4T N J ` aD o ° o y4 'r it - ali� t t•i I ' �.-, � 34°57 25"N 34'57 25"N s�- 662&l0 662900 663000 663100 6632DD 663300 663400 663500 663600 663700 663800 3 3 Map Scale:1:4,700 if printed on A landscape(11"x 8.5")sheet. Meters N 0 50 100 200 300 Feet 0 200 400 800 1200 Map projection:Web Mercator Comer coordinates:WGS84 Edge tics:UTM Zone 17N WGS84 G}DA Natural Resources Web Soil Survey 12/2/2023 Conservation Service National Cooperative Soil Survey Page 1 of 4 Hydrologic Soil Group—Hoke County, North Carolina (Hydrologic Soils Group) MAP LEGEND MAP INFORMATION Area of Interest(AOI) p C The soil surveys that comprise your AOI were mapped at Area of Interest(A01) 0 C/D 1:24,000. Soils D Warning:Soil Map may not be valid at this scale. Soil Rating Polygons � A p Not rated or not available Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil 0 A/D Water Features line placement.The maps do not show the small areas of Streams and Canals contrasting soils that could have been shown at a more detailed 0 B scale. Transportation 0 B/D Rails Please rely on the bar scale on each map sheet for map 0 C measurements. '.,,r Interstate Highways 0 C/D US Routes Source of Map: Natural Resources Conservation Service Web Soil Survey URL: 0 D Major Roads Coordinate System: Web Mercator(EPSG:3857) Not rated or not available Local Roads Maps from the Web Soil Survey are based on the Web Mercator Soil Rating Lines Background projection,which preserves direction and shape but distorts q distance and area.A projection that preserves area,such as the ® Aerial Photography Albers equal-area conic projection,should be used if more • A/D accurate calculations of distance or area are required. +'* B This product is generated from the USDA-NRCS certified data as B/D of the version date(s)listed below. x C Soil Survey Area: Hoke County, North Carolina Survey Area Data: Version 21,Sep 13,2023 P1 0 C/D Soil map units are labeled(as space allows)for map scales * r D 1:50,000 or larger. r Not rated or not available Date(s)aerial images were photographed: Apr 17,2022—May Soil Rating Points 20,2022 p A The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background p A/D imagery displayed on these maps.As a result,some minor B shifting of map unit boundaries may be evident. B/D UU� Natural Resources Web Soil Survey 12/2/2023 � Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group—Hoke County,North Carolina Hydrologic Soils Group Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI AuA Autryville loamy sand,0 A 15.5 19.6% to 2 percent slopes CaB Candor sand, 1 to 8 A 15.9 20.1% percent slopes Co Coxville loam C/D 37.2 47.1% NoA Norfolk loamy sand,0 to A 8.5 10.7% 2 percent slopes NoB Norfolk loamy sand,2 to A 1.9 2.4% 6 percent slopes Ra Rains sandy loam,0 to A/D 0.1 0.1% 2 percent slopes Totals for Area of Interest 79.0 100.0% USDA Natural Resources Web Soil Survey 12/2/2023 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group—Hoke County,North Carolina Hydrologic Soils Group Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential)when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential)when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff. None Specified Tie-break Rule: Higher usDA Natural Resources Web Soil Survey 12/2/2023 Conservation Service National Cooperative Soil Survey Page 4 of 4