20181252 Ver 2_R-5735 RAB - Cheorkee County - SMP_20230713

l,til I` North Carolina Department of Transportation
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STORMWATER MANAGEMENT PLAN y""w^^�"'
(Version 2.07;Released October 2016) FOR NCDOT PROJECTS
WBS Element: 50193.1.1 TIP No.: R-5735 County(ies): Cherokee Page 1 of 2
General Project Information
WBS Element: 50193.1.1 ITIP Number: R-5735 Project Type: Roadway Widening Date: 12/18/2017
NCDOT Contact: David McHenry Contractor/Designer: MI Engineering/Karen Hefner,PE
Address: 253 Webster Road Address: 1011 Schaub Drive
Sylva,NC 28779 Suite 100
Raleigh,NC 27606
Phone: [phone] Phone:[phone]
Email:dgmchenry(a)ncdot.gov Email: khefner(a)rri-engineers.com
City/Town: Murphy,NC County(ies): I Cherokee
River Basin(s): Hiwassee CAMA County? I No
Wetlands within Project Limits? Yes
Project Description
Project Length(lin.miles or feet): 1.22 Surrounding Land Use: Business/Commercial
Proposed Project Existing Site
Project Built-Upon Area(ac.) 11.8 ac. 11.4 ac.
Typical Cross Section Description: The proposed project will consist of 1 @12',1 @14'EBL and 2@12'WBL with a 12' US 19/US 74/US 64/US 129(-L-)is a 2@12'travel lanes in both directions with a
center turn lane for a portion of the project. The other portion consists of 1 @12',1 @14' center turn lane of 12',with curb&gutter and some sidewalk.There is approximately
travel lanes(EBL)and a 12'left turn lane. The WBL will consist of 1@12',1@14'with a 600'of shoulder section at the beginning of the project.Hiwassee Street/US 19 Bus.(-
variable width(16'to 20')monolithic island. -Y3-(new location)consists of 2@12'lanes Y5-)is 2@12.5'travel lanes in both directions,with sidewalk on the east side. Old
with a 12'right turn lane at intersection of-L-. -Y3A consists of 2@6'lanes with curb& Ranger Rd(SR1398)(-Y1-)is 2@10'travel lanes with curb&gutter.
gutter on one side. -Y4A-(new location)consists of 2@12'lanes with curb&gutter on
both sides.
Annual Avg Daily Traffic(veh/hr/day): Design/Future: 24,000 Year:2040 Existing: 19,900 Year: 2020
General Project Narrative: Due to the large amount of existing development and the steep topography along the project corridor space is very limited to provide storm water treatment.Most of the existing
(Description of Minimization of Water roadway is curb and gutter with storm drainage networks that drain to a Unnamed Tributary(UT)to the Hiwassee River that runs parallel to the north side of the project. The UT
Quality Impacts) to the Hiwassee River is piped underneath businesses in various sized pipes for most of the project length.There have been numerous sink holes and failures where the UT to
the Hiwassee River has been piped.Therefore to relieve some of the Hydraulic pressure on these existing pipes,the majority of the roadway drainage is proposed to be
collected and piped along the project length and discharged into a energy dissipator basin located on the west side of Hiwassee Street just North of Ranger Road. Space for
treatment is also limited along the South side of the project due to steep topography directly adjacent to project as well as commercial development.Some treatment will be
provided on the west end of the project by discharging drainage into a riprap lined ditch and through a small wetland area.
Waterbody Information
Surface Water Body(1): Hiwassee River NCDWR Stream Index No.: 1-(50)
NCDWR Surface Water Classification for Water Body Primary Classification: Class C
Supplemental Classification:
Other Stream Classification:
Impairments:
Aquatic T&E Species? Comments:
NRTR Stream ID: Buffer Rules in Effect: N/A
Project Includes Bridge Spanning Water Body? INo Deck Drains Discharge Over Buffer? I N/A Dissipator Pads Provided in Buffer? I N/A
Deck Drains Discharge Over Water Body? I N/A (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)

Highway North Carolina Department of Transportation `
Sturn-water
Highway Stormwater Program s✓�
STORMWATER MANAGEMENT PLAN
(Version 2.07;Released October 2016) FOR NCDOT PROJECTS
WBS Element: TIP No.: R-5735 County(ies): Cherokee Page 2 of 2
Preformed Scour Holes and Energy Dissipators
Station&Coordinates Drainage Pipe/Structure BMP
Sheet (Road and Non Road Surface Energy Dissipator Area Conveyance Dimensions Q10 V10 Associated w/
No. Projects) Water Body Type Riprap Type (ac) Structure (in) (cfs) (fps) Buffer Rules?
9 39+50-Y1A-LT (1)Hiwassee Riprap Energy Class II 67.7 Pipe 66"RCP-IV 167.0 5.9 N/A
River Dissipator Basin
9 39+50-Y1A-LT (1)Hiwassee Riprap Energy Class II 477.0 Pipe 84"RCP-IV 323.0 19.9 N/A
River Dissipator Basin
Additional Comments
Refer to the NCDOT Best Management Practices Toolbox(2014),NCDOT Standards,the Federal Highway Administration(FHWA)Hydraulic Engineering Circular No.14(HEC-14),Third Edition,Hydraulic Design of Energy
Dissipators for Culverts and Channels(July 2006),as applicable,for design guidance and criteria.