20070173 Ver 2_R-5769 Conceptual Stormwater Mangement Plan Corrected_20160301

From: Kevin Alford <KAlford0»wethehUengzom>
Sent: Tuesday, March Ul'ZUl6Z:Z6 PM
To: 8urdette,Jennifer a
Cc: Coggins, Tony[; Greg Pun/is
Subject: R'5760StormvvaterK4angementPlan
Attachments: R'5760STORK4VVATERMANAGEMENT PLAN -REV 3'l'l6.doc
]ennifer,
Attached isarevised stormwmtermanagement plan for R-5769. Wording has been revised tostate that there bastream
crossing ofanunnamed tributary toLittle Poplar Creek.
I apologize for the mistake. Thanks for your help.
Kevin B. Alford, PE
1223 Jones Franklin Rd.
Raleigh, NC 27606
Office: [phone]
Mobile: [phone]
Fax: [phone]
Direct: [phone]
ET RE Ft"ItIL
-,-00000' WIFE-NGINEERIN�G
Please update your records with our new address
and forward toyour accoundnm/biling departments
so we can promptly receive and respond to your
mailings.
lJJ3Jones Franklin Road, Raleigh, N[J76O6-33lJ
Wommn oq'�.)'.
a I IJ"3JpA$ un KtA* &n"vvrvq
Po�������
����

STORMWATER MANAGEMENT PLAN
March 1, 2016
Project: R-5769
County: Johnston
ROADWAY DESCRIPTION
The project R-5769 is a proposed access road from SR 1905 (Gordon Road) to the
proposed Novo Nordisk site. A majority of the project is on new location, including a
proposed bridge crossing of Norfolk Southern railroad. The total approximate project
length is 0.64 miles. The project is located within the Neuse River Basin and eventually
flows to Little Poplar Creek. The project will impact the surrounding wetlands located
along the project alignment. The project drainage consists of grass lined ditches, grated
inlets with associated pipe systems and rip rap dissipater pads at the pipe outlets.
ENVIRONMENTAL DESCRIPTION
The project is located within the Neuse River Basin, which buffer regulations have been
implemented. The project crosses an unnamed tributary to Little Poplar Creek. Little
Poplar Creek is listed on the NCDENR classifications list as a Class WS -IV, NSW.
Little Poplar Creek is not listed on the 303(4) list for impaired streams. There are
wetland sites along the proposed alignment that will be impacted by the proposed project.
Impacts will be minimized by using rip rap dissipater pads at the pipe outlets and sheet
flow along fill slopes. Any discharge to wetland areas will be at non-erosive velocities.
BEST MANGEMENT PRACTICES AND MAJOR STRUCTURE
The primary goal of Best Management Practices (BMP's) is to prevent degradation of the
states surface waters by location, construction and operation of the highway system. The
BMP's are activities, practices and procedures taken to prevent or reduce stormwater
pollution. The BMP measures used on this project to reduce stormwater impacts are:
Rip Rap Dissipater Pads
Rip Rap pads dissipater pads will be used in order to dissipate energy and
attain non-erosive velocities at pipe outlets. These structures will be used
at the pipe outlets in the wetlands in lieu of Preformed Scour holes to
prevent excavation in wetlands. Preformed scour holes may be utilized at
non wetland discharge locations.
• Fill Slopes
Fill slopes within the wetlands will allow sheet flow from the proposed
roadway in order to minimize discharge from piped drainage systems.
Also, in high fill areas, such as in the area of the proposed rail crossing,
1.5:1 armored fill slopes will be used in wetlands in order to minimize the
impact of the fill slope to the wetlands.