20171102 Ver 1_SW Diffuse Flow Plan_20170901

(Version 2.06; Released June 2016)17BP.5.R.54TIP No.:BMU-310117County(ies):Durham Page 1 of 1TIP Number:Date:Phone:Phone:Email:Email:County(ies):CAMA County?YesDesign/Future: Year:2025Existing: Year:Aquatic T&E Species?NoComments:Yes NoNoWetlands within Project Limits?Nutrient Sensitive Waters (NSW)Supplemental Classification: Wooded, low residential Mud Creek16-41-1-100.60.230 milesProject DescriptionProposed ProjectCape FearRiver Basin(s): City/Town:0.9Typical Cross Section Description: Surrounding Land Use: General Project Narrative:(Description of Minimization of Water Quality Impacts)[e-mail], NC 27560Address:1/12/2017DurhamDurhamMatthew Lauffer, PE1590 Mail Services UnitWBS Element:Bridge ReplacementWBS Element:Trent Cormier, PENCDOT Contact:(919) 707-67035121 Kingdom Way, Suite 100Raleigh, NC 27607Contractor / Designer:[phone]ICA Engineering, Inc.North Carolina Department of TransportationHighway Stormwater Program STORMWATER MANAGEMENT PLAN FOR NCDOT PROJECTSProject Type:NCDOT Hydraulics UnitAddress:General Project InformationBMU-31011717BP.5.R.54Impairments:Other Stream Classification: Primary Classification: Project Built-Upon Area (ac.)The North Carolina Department of Transportation (NCDOT) has proposed to replace Durham County Bridge #117 over Mud Creek on West Cornwallis Road (SR 1308). The exisiting sturcture has 3 spans: 1@17'4; 1@17; 1@17'8 with an overall length of 52', and is a timber deck supported by timber caps and timber piles. The proposed structure is a single span 1@70, 24" pre-stressed concrete cored slab bridge. The proposed bridge will have spill through abutments with 4' caps skewed at 90 degrees. Within the project limits, Mud Creek is a FEMA Zone AE redelineated detail studied stream. This structure has been designed to have as little environmental and surface water impacts as possible. Excavation was kept to a minimum and was kept outside of the existing natural top of banks. There are exisiting roadside ditches which end at wetland boundaries with non-erosive volicities.There are proposed roadside ditches lined with rip-rap to prevent erosive velocities. In the areas that don't have proposed ditches, there will be sheet flow through the grass shoulder areas to provide stormwater treatment for pavement runoff before entering the wetlands with non-erosive velocities. The rip-rap pad at the pipe outlet was designed to dissipate energy to proved a diffuse (sheet) flow to the wetland. Variable roadway fill slopes of 3:1 and 2:1 were designed to minimize impacts to the wetlands. Jordan LakeBuffer Rules in Effect:3300W Cornwallis Road (SR 1308): Two 11' paved lanes (total 22' wide), 4' paved shoulder on each side.Waterbody Information2011NCDWR Stream Index No.:NRTR Stream ID:Annual Avg Daily Traffic (veh/hr/day):Existing SiteProject Length (lin. miles or feet): ac.Surface Water Body (1): Water Supply V (WS-V) NCDWR Surface Water Classification for Water Bodyac.W Cornwallis Road (SR 1308): Two 10.5 ' paved lanes (total 21' wide), Unpaved [e-mail] Includes Bridge Spanning Water Body? Deck Drains Discharge Over Buffer? Dissipator Pads Provided in Buffer?N/ADeck Drains Discharge Over Water Body?(If yes, provide justification in the General Project Narrative) (If yes, describe in the General Project Narrative; if no, justify in the General Project Narrative)(If yes, provide justification in the General Project Narrative)