20190118 Ver 2_SWMP 17BP.5.R.66_20190402

Atltlress: NCDOT Hydraulics Unit
1590 Mail Services Unit
Ralei h, NC 27560
Phone: [phone]
Email: mslauffer ncdot. ov
vn: Louisbur
asin s : Tar-Pamlico
is within Project Limits? Yes
Length (lin. miles or feet): � 0.114 miles S
Pra�
Built-Upon Area (ac.) 0.28
Cross Section Description: Pete Smith Road (SR 1412): 2 paved la
with guardrail).
ial Avg Daily Traffic (veh/hr/day):
�ral Project Narrative:
cription of Minimization of Water
ity Impacts)
HDR Engineering, Inc.
555 Fayetteville Street, Suite 900
Email: k
Franklin
Land Use: �Low Residential, Wooded
on
m
on
e North Carolina Department of Transportation (NCDOT) has proposed to replace Franklin County Bridge #50 on Pete Smith Road (SR 1412) over Devils Cradle Creek. The
isting structure is a six span bridge (1@10'2"; 1@10'3"; 1@9'6"; 1@10'6"; 1@14'9"; 1@15'5") and is a timber deck on I-Beams supported by timber caps on timber piles for
� interior and end bents. The proposed structure is a single span (1@90'), 33" box beam with 4' deep caps. This structure has been designed to have as little environmental,
�iland, and surtace water impacts as possible. 2:1 roadway fill slope will be used in the wetland areas to minimize wetland impacts. Geoteutile and Class II rip-rap was utilized
bank stabilization to reduce stream bank erosion along the north and south bank of the channel underneath the bridge.
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
nimized by utilizing grated inlets and pipes to collect bridge storm water and use rip rap outlet protection at 13+75 RT to dissipate energy to provide a diffuse flow (non-erosive
eet flow) in a wooded area. This diffuse flow will run for a distance of 10'+/- in a special cut ditch before entering the buffer. At the same (SE) quadrant an existing roadside
ch has outlet at 14+07 RT and will be turned out with a non-erosive outlet velocity. This diffuse flow runs for a distance of 40+/- before entering the stream. At the SW
adrant there is an existing ditch that outlets at 13+gg LT with a non-erosive outlet velocity . The roadway is in fill section and runoff discharges as sheet flow off the pavement
ough grassed shoulder and fill slope or wooded area to remove pollutants via infiltration and settling before entering the wetland or buffer on the west side of the road. In the
V quadrant, there is an existing ditch that outlets at 15+13 LT with a non-erosive outlet velocity. This ditch will be retained and lined with toe protection along the fill slope. At
� NE quadrant an existing roadside ditch has outlet at 16+g0 RT with a non-erosive outlet velocity. This diffuse flow runs for a distance of 20+/- before entering the wetland on
� northeast side of the bridge. This ditch will be retained. Due to the nature of low impact bridge replacement, the increases in stormwater discharges (postvs pre condition)
� insignificant and the existing ditches do not need to be modified. Therefore, additional stormwater measures are not required.
CDWR Surtace Water Classification for Water Body
ther Stream Classification: None
ipairments: None
uatic T&E S ecies? No Comments:
RTR Stream ID:
ro'ect Includes Brid e S annin Water Bod ? Yes
eck Drains Discharae Over Water BodJ? No
Classification: Class B
:mental Classification: NSW : +
)rains Discharge Over Buffer? �
yes, provide justification in the General Project N;
Buffer Rules in Effect: Tar-Pamlico
Dissipator Pads Provided in Buffer? No
(If yes, describe in the General Project Narrative; if no, justify in
General Project Narrative)