20190112 Ver 1_SWMP 17BP.5.R.70_20190125

Highway North Carolina Department of Transportation
Stormwater !`��
,,,.,,,,,,, Highway Stormwater Program \�
STORMWATER MANAGEMENT PLAN —
(Version 2.07; Released October 2016) FOR NCDOT PROJECTS
WBS Element: 17BP.5.R.70 TIP No.: SF-340028 County(ies): Franklin Page 1 of 1
Generel Project Information
WBS Element: 17BP.5.R.70 TIP Number: SF-340028 Project Type: Bridge Replacement Date: 1/7/2019
NCDOT Contact: Matthew Lauffer, PE Contractor I Designer: K le Stoffer, EI
Address: NCDOT Hydraulics Unit Address: HDR Engineering, Inc.
1590 Mail Services Unit 555 Fayetteville Street, Suite 900
Raleigh, NC 27560 Raleigh, NC 27601
Phone: [phone] Phone: [phone]
Email: mslauffer ncdot. ov Email: k le.stoffer hdrinc.com
City/Town: Franklinton Count ies : Franklin
River Basin(s): Tar-Pamlico CAMA County? No
Wetlands within Project Limits? No
Pro'ect Description
Project Length (lin. miles or feet): 450 feet (0.085 miles) Surrounding Land Use: �/ooded, Rural
Proposed Pro'ect Existin Site
Pro'ect Built-Upon Area ac. 0.2 ac. 02 ac.
Typical Cross Section Description: Montgomery Rd (SR 1210): 2 paved lanes (total 20' wide), 4' shoulder on each side (7' Montgomery Rd (SR 1210): 2 paved lanes (total 18' wide), 6' shoulder on each side
shoulder with guardrail).
Annual Avg Daily Traffic (veh/hrlday): Design/Future: 1120 Year: 2025 Existing: 560 Year: 2011
General Project Narrative: The North Carolina Department of Transportation (NCDOT) has proposed to replace Franklin County Bridge #28 on Montgomery Road (SR 1210) over Billys Creek. The existing
(Description of Minimization of Water structure is a two span bridge (2@20'3") and is a timber deck on I-Beams supported by timber caps on timber piles for the interior and end bents. The proposed structure is a
Quality Impacts) one span (1 @55'), 21" cored slab with 4' deep caps. This structure has been designed to have as little environmental, and surface water impacts as possible. Geotextile and rip-
rap was utilized for bank stabilization in an attempt to reduce stream bank erosion along the north and south 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 14+75 RT to dissipate energy to provide a diffuse flow (non-erosive
sheet flow). This diffuse flow will run for a distance of 10'+/- in a grassed/wooded area before entering the buffer. At the same (NE) quadrant an existing roadside ditch has outlet
at 16+63 RT with a non-erosive outlet velocity. This diffuse flow runs for a distance of 160'+/- before entering the buffer. This ditch will be retained. At the NW quadrant an
existing roadside ditch outlets at 16+00 LT with a non-erosive outlet velocity. This diffuse flow runs for a distance of 150+/- before entering the buffer. This ditch will be retained.
At the SW quadrant, an existing roadside ditch has outlet at 12+42 LT with a non-erosive outlet velocity. This diffuse flow runs for a distance of 100+/- before entering the buffer.
This ditch will be retained. At the SE quadrant an existing roadside ditch has outlet at 12+g3 RT with a non-erosive outlet velocity. This diffuse flow runs for a distance of 65+/-
before entering the buffer. This ditch will be retained. For all four quadrants within the project limits, the roadway is in fill section and runoff discharges as sheet flow off the
pavement through grassed shoulder and fill slope or wooded area to remove pollutants via infiltration and settling before entering the buffer. Due to the nature of low impact
bridge replacement, the increases in stormwater discharges (post vs pre condition) are insignificant and the existing ditches do not need to be modified. Therefore, additional
stormwater measures are not required.
Waterbod Information
Surface Water Body (1): Billys Creek NCDWR Stream Index No.: 28-20
NCDWR Surtace Water Classification for Water Body Primary Classification: Water Supply IV (WS-IV)
Supplemental Classification: Nutrient Sensitive Waters (NSW
Other Stream Classification: None
Impairments: None
Aquatic T&E Species? No Comments:
NRTR Stream ID: Buffer Rules in Effect: Tar-Pamlico
Pro'ect Includes Bridge Spannin Water Body? Yes Deck Drains Dischar e Over Buffer? No Dissipator Pads Provided in Buffer? No
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)