20210111 Ver 1_Steeplechase Stormwater Plans_20210407

Highway North Carolina Department of Transportation
Stormwater
Highway Stormwater Program
STORMWATER MANAGEMENT PLAN
(Version 2.08; Released April 2018) FOR NCDOT PROJECTS
WBS Element: 17BP.7.R.128 TIP No.: SF-400025 County(ies): Guilford Page 1 of 1
General Project Information
WBS Element: 17.BP.7.R.128 TIP Number: SF-400025 Project Type: Bridge Replacement Date: 1/14/2021
NCDOT Contact: Tim Powers, PE Contractor/ Designer: Eleni M. Riggs, PE
Address: Highway Division 7 Address: Mott MacDonald
1584 Yanceyville Street, PO Box 14996 7621 Purfoy Road, Suite 115
Greensboro, NC 27415 Fuquay Varina, NC 27526
Phone: [phone] Phone: [phone]
Email: [e-mail] Email: eleni.riggs(amottmac.com
City/Town: Greensboro County(ies): Guilford
River Basin(s): Cape Fear CAMA County? No
Wetlands within Project Limits? No
Project Description
Project Length (lin. miles or feet): 0.149 miles Surrounding Land Use: Wooded, agricultural
Proposed Project Existing Site
Project Built-Upon Area (ac.) 0.7 ac. 0.6 ac.
Typical Cross Section Description: E Steeple Chase Rd (SR 1105): 2 paved lanes (total 22'wide), 4'3" paved shoulder on E Steeple Chase Rd (SR 1105): 2 10' paved lanes (total 20'wide), 6' non-paved
each side shoulder on each side
Annual Avg Daily Traffic (veh/hr/day): Design/Future: 1500 Year: 2025 Existing: 750 Year: 2015
General Project Narrative: The North Carolina Department of Transportation (NCDOT) has proposed to replace Guilford County Bridge#025 on East Steeple Chase Rd (SR 1105) over Polecat Creek.
(Description of Minimization of Water The existing structure is a two span bridge (1 @35'-6" and 1 @35'-5") and is a steel plank deck on I-Beams supported by timber caps. The proposed structure is a single span
Quality Impacts) 39" prestressed box beams with 4' deep caps, 1 @105'. This structure has been designed to have as little environmental and surface water impacts as possible. There are no
wetlands or buffers present in this project. Geotextile and rip-rap was utilized for bank stabilization in an attempt to reduce stream bank erosion along the east bank of the
channel underneath the bridge. To avoid direct discharge of bridge storm water into the receiving water, deck drains are not required for the proposed bridge. Storm water
impacts to the stream have been minimized by utilizing grated inlets and pipes to collect bridge storm water and use rip rap outlet protection at station 13+91 LT to dissipate
energy to provide a non erosive flow into the stream. The flow will run for a distance of 76' +/-through rip-rap and geotextile before entering the stream, providing time to remove
pollutants from the water. In both the NE and SE quadrant, there are lateral V roadside ditches to collect runoff with outlets at stations 13+15 LT and 13+77 RT, and lengths of
485'+/- and 423'+/- respectively. The roadway is a typical fill section and runoff discharges into the roadside ditches before discharging into the stream. In the SW quadrant,
there are no roadside ditches. The roadway is fill section and runoff discharges as sheet flow off the pavement through grassed shoulder and fill slope into the adjacent wooded
area to remove pollutants via infiltration and settling on the south side of the road. In the NW quadrant, there is bank stabilization and toe protection along the fill slope with
length 117'+/-with outlet at station 12+67 LT with a non-erosive outlet velocity to the stream. Due to the nature of low impact bridge replacement, the increases in stormwater
discharges (post v. pre condition)are negligible.Therefore additional stormwater measures are not required.
Waterbody Information
Surface Water Body (1): Polecat Creek NCDWR Stream Index No.: 17-11-(1)
NCDWR Surface Water Classification for Water Body Primary Classification: Water Supply III (WS-III) None
Supplemental Classification: None None
Other Stream Classification: None _
Impairments: None
Aquatic T&E Species? No Comments:
NRTR Stream ID: Buffer Rules in Effect: N/A
Project Includes Bridge Spanning Water Body? Yes Deck Drains Discharge Over Buffer? No Dissipator Pads Provided in Buffer? N/A
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)