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Home My WebLink About20171524 Ver 1_SW Plan_20171129k li�%I l�t'�n' North Carolina Department of Transportation , �,li)1'l l]tiYatPf Highway Stormwater Program _�. STORMWATER MANAGEMENT PLAN ��••-=��r (Version 2.07; Released October 2016) FOR NCDOT PROJECTS WBS Element: 50138.1.120 TIP No.: W-5601 DO County(ies): Johnston Page 1 of 3 General Project Information WBS Element: 50138.1.120 TIP Number: W-5601D0 ProjectType: Roadway Widening Date: 11/28/2017 NCDOT Contact: Dennis Ethrid e Contractor / Designer: TGS Engineers (Ben J. Henegar, PE Address: 509 Ward Blvd. Address: 706 Hillsborough Street P.O. Box 3165 Suite 200 Wilson, NC 27895 Raleigh, NC 27603 Phone: 252-640-6424 Phone: 919-773-8887 ext. 123 Email: drethrid e ncdot. ov Email: bhene ar t sen ineers.com Cit ITown: Selma Count ies : Johnston River Basin(s): Neuse CAMA County? No Wetlands within Project Limits? No Pro'ect Description Project Length (lin. miles or feet): 0.122 mi. Surrounding Land Use: Commercial, cropland, woodland Proposed Pro'ect Existin Site Pro'ect Built-Upon Area ac. 1.4 ac. 1.3 ac. Typical Cross Section Description: Four-lane divided roadway with 12' lanes, raised median, 2.5' curb and gutter, and Four lane divided roadway with 12' lanes, raised median, 2.5' curb and gutter, and roadside ditches. 12' right-hand turning lane added to RT side. roadside ditches. Annual Avg Daily Traffic (veh/hr/day): Design/Future: 15,000 Year: 2016 Existin : 15,000 Year: 2016 General Project Narrative: W-5601 DO is a state safety improvement project which involves the addition of a right-turn lane on US 70 through Selma between I-95 and Wilson Mills. The existing facility is (Description of Minimization of Water a four-lane divided roadway. The project includes an existing jurisdictional stream crossing, closed system drainage, and roadside ditches. EC matting should be placed along Quality Impacts) toe of fill through existing ditches to allow for swale treatment for flow entering jurisdictional area right of US 70 Business. The proposed system (Str. 0416) could not outlet outside of the buffers because of insufficient fall into the existing RT ditch. Deepening the ditch was not an option due to R/W constraints of this safety improvement project. The existing outlet pipe could also not be retained due to insufficient drop. The outlet location inside the buffers is the same as the existing condition, and a standard rip rap pad was used at outlet to dissipate energy and promote diffuse flow into jurisdictional area. The existing base ditch on the left of US 70 Business will replaced with 48" RCP-III to correct existing erosion and slope degradation observed in the field. Waterbody Information Surface Water Body (1): Unnamed Tributary NCDWR Stream Index No.: N/A NCDWR Surface Water Classification for Water Body Primary Classification: None Supplemental Classification: None Other Stream Classification: None Impairments: None Aquatic T&E Species? No Comments: NRTR Stream ID: N/A Buffer Rules in Effect: Neuse Project Includes Bridge Spanning Water Body? No Deck Drains Discharge Over Buffer? No Dissipator Pads Provided in Buffer? Yes Deck Drains Discharge Over Water Body? No (If yes, provide justification in the General Project Narrative) (If yes, describe in the General Project Narrative; if no, justify in the (If yes, provide justification in the General Project Narrative) General Project Narrative) �::: :.� k{j�k��:'�1�, North Carolina Department of Transportation S l Ul'1 YY4Y'c14PC Highway Stormwater Program .� STORMWATER MANAGEMENT PLAN •-- ' (Version 2.07; Released October 2016) FOR NCDOT PROJECTS WBS Element: 50138.1.120 TIP No.: W-5601D0 Count ies : Johnston Pa e 2 of 3 Swales Station & Coordinates Surface Base Front Back Drainage Recommended Actual Longitudinal Rock BMP Sheet (Road and Non Road Water Width Slope Slope Area Treatm't Length Length Slope Q2 V2 Q10 V10 Checks Associated w/ No. Pro'ects Bod it H:1 H:1 ac ft ft °/a cfs f s cfs f s Used Buffer Rules? 4 -Y28- 14+25 RT (1)Unnamed 0.0 3.0 3.0 1.8 180 200 1.53°/ 3.6 1.9 8.0 3.0 No Yes 35.52579 / -78.30124 Tributary 4 -Y28- 17+46 RT (1)Unnamed 0.0 3.0 3.0 0.5 50 130 2.26°/ 1.7 2.0 1.3 2.1 No Yes 35.52525 / -78.30037 Tributary Additional Comments The ditches analyzed above are formed at the proposed toe of fill (3:1) and the exiting ground. �-.�_ ;. 1 ll�;f]tiV�l�, North Carolina Department of Transportation SlC]Y'll]tiVcltt'�' Highway Stormwater Program STORMWATER MANAGEMENT PLAN —' (Version 2.07; Released October 2076) FOR NCDOT PROJECTS WBS Element: TIP No.: W-5601 DO Count ies : Johnston Pa e 3 of 3 Preformed Scour Holes and Energy Dissipators Station & Coordinates Drainage Pipe/Structure BMP Sheet (Road and Non Road Surface Energy Dissipator Area Conveyance Dimensions Q10 V10 Associated w/ No. Pro'ects Water Bod Type Riprap T pe ac Structure (in) (cfs) (fps) Buffer Rules? 4 -Y28- 14+18 RT (1)Unnamed Riprap Pad Class'B' 3.1 Pipe 24 11.7 1.3 Yes 35.5258 / -78.30124 Tributary Additional Comments Proposed pipe outlet is at same location as existing storm drainage outlet inside buffers. � Refer to the NCDOT Best Management Practices Toolbox (2014), NCDOT Standards, the Federal Highway Administration (FHWA) Hydraulic Engineering Circular No. 14 (HEC-14), Third Edition, Hydraulic Design of Energy Dissipators for Culverts and Channels (July 2006), as applicable, for design guidance and criteria.