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Home My WebLink About20120419 Ver 1_More Info Received_20120618�IZA4 m�, STATE OF NORTH CAROLINA DEPARTNIENT OF TRANSPORTATION BEVERLY EAVES PERDUE GOVERNOR Mr David Wainwright NC Division of Water Quality 1650 Mail Service Center Raleigh NC 27699 1650 ATTN Ms Amy Euliss NCDOT Coordinator Dear Madam June 13 2012 NI8�� EUGENE A R SECRETARY 2- U'-4Z U Subject REQUEST FOR THE LIFTING OF "ON HOLD STATUS" for the Section 401 Water Quality Certification for the proposed replacement of Bridge No 118 over Lanes Creek on SR 1937 (Old Pageland Marshville Road) in Union County Federal Aid Project No BRZ 1937(2) Division 10 TIP No B 4652 WBS 33818 11 Reference NCDOT Permit Application for a 404 Permit and 401 Water Quality Certification dated April 13 2012 NCDWQ on hold letter notification dated May 30 2012 This letter is in response to the NC Division of Water Quality s (DWQ) Incomplete Application Notification for Transportation Improvement Project B 4652 In this letter the DWQ indicated 'A site visit indicates that the streambank for the proposed slope reinforcement appears to be fairly stable (including trees) It is unclear why this activity is necessary as the new bridge will be longer and provide additional floodplain availably for the stream Additional floodplarn availability will allow for energy dissipation on the floodplarn rather than the streambanks Provide information to support the request for the proposed 74 linear feet of stream impact Additionally if the need for the impact can be supported DWQ does not typically authorize stabilization using gabions and would prefer a more natural method of streambank stabilization Please provide an alternative form of stream bank stabilization ' NCDOT Response Though the current bank identified above is currently stable, it is evident that channel flow has over time impacted the upstream right bank causing the channel to migrate behind the MAILING ADDRESS TELEPHONE 919 707 6000 LOCATION NC DEPARTMENT OF TRANSPORTATION FAX 919 250 4224 CENTURY CENTER BUILDING A PROJECT DEVELOPMENT AND ENVIRONMENTAL ANALYSIS 1000 BIRCH RIDGE DRIVE 1548 MAIL SERVICE CENTER WEBSITE WWW NCDOT ORG /DOH /PRECONSTRUCT /PE/ RALEIGH NC 27610 RALEIGH NC 27699 1548 existing bridge s end bent This is shown in the enclosed Figure 1 which is the plan view from the Bridge Survey Report In the bridge profile view also depicted in Figure 1 shows that despite having a longer proposed structure it does not provide any additional significant flow area in the floodplain than the existing bridge The excavation (hatching) shown on the left (right upstream bank yellow arrow) has been done to provide minimal area for future structure inspections and not increased floodplain flow The design year and 100 year flood events do not even reach this excavated area The attached plan sheet with contours (Figure 3) may help display a clearer picture of the situation Photos are also included (Figure 2) which indicate damage from erosion of this bank trees leaning in towards the channel and that this bridge has experienced flooding events exceeding the 100 year event (see the debris caught in the existing bridge s superstructure) NCDOT Hydraulics Unit designed a longer bridge per the Department s minimum bridge criteria which specifics that we set back the proposed bridge 10 feet or more from the top of bank (TB in the plan view below) We believe that the gabion mattress bank reinforcement is warranted to impede channel migration which could occur during excessive flooding events This mattress is designed to be placed on top of the existing bank and stay in place (not launch stabilization material into the channel) If left unprotected the channel migration could over the life of the new structure cause the right abutment to fail In the Department s Hydraulic model the average Design (25 year) channel velocities are near 7 feet per second As flow impacts this bank flow vortices and increased velocities occur which cannot be numerically determined without a much more complex hydraulic model Therefore the best structure in this situation to handle the velocities is the use of a gabion mattress NCDOT feels the above explanation satisfies the deficiency noted on your letter dated May 2 2012 and the Department hereby requests the lifting of the On Hold Status and subsequent processing of the application thereof A copy of this request and its distribution list will be posted on the NCDOT Website at http / /www ncdot org /doh /preconstruct /pe /neu /permit html If you have any questions or need additional information please contact Michael Turchy at maturchv @ncdot gov or (919) 7076157 Sincerely Gregory J Thorpe Ph D Branch Manager Project Development and Environmental Analysis Unit cc NCDOT Permit Application Standard Distribution List Figure 1 URIMMISUIUM i one j■■■o • • • sill • � a�ltttttl ■ttttltl��l..�_ —'� +!� •� • , 101 A70.0-; WMEM • • s ■ ■� ■tom � . N L" ID SKEWW 1, on aml HIM m I • L� 11 m iil� �iiiiiiii�•' �/ /`mil -• f.�.�'_• •��iiiii{ �iiiaii ��1.�73 - - :I :11:11 '�• � � , • � • �� • 11 {/1 24 Wo {L1{ . •.�lr•��na'.uiu •iuw rl.� ;��!�gdl�q.��aA _� s- s M• '1��P_!►:�•r'L� •i r ••••• =�__ a_� 1Nliti'i _ •.•.v•• � �!��?� ?�._l�i.l� iil� �iiiiiiii�•' �/ /`mil -• f.�.�'_• •��iiiii{ �iiiaii ��1.�73 - - Figure 2 Photos: Right Upstream Abutment (same side as the bank in question). Upstream facing k Ige (bank in question on right). Subsidence noted with bent trees. \ 1 9 ,N Condition Photos from Bridge Maintenance Inspection Report: Bridge K. R9011E ccunly. UNION Caw 04110;2006 Condnion Photos s� A H GH V4AicH S!G4S Oh ?I-4E CAPS i a` NCDENR North Carolina Department of Environment and Natural Resources Division of Water Quality Beverly Eaves Perdue Charles Wakild, P. E. Dee Freeman Governor Director , Secretary, May 30, 2012 CERTIFIED MAIL 7009 2250 0004 3265 6735 RETURN RECEIPT REQUESTED Dr. Gregory J. Thorpe, Manager NCDOT Project Development and Environmental Analysis Unit 1548 Mail Service Center Raleigh, NC 27699 SUBJECT: Proposed Bridge Replacement (Bridge 118) over Lanes Creek on SR 1937 (Old Pageland Marshville Road), Federal Aid Project No. BRZ- 1937(2), Union County, TIP B -4652, DWQ No. 2012 -0420 Dear Dr. Thorpe: The Division of Water Quality (DWQ) has reviewed your submittal for a 401 Water Quality Certification for the aforementioned project. A review of your request revealed it is lacking the necessary information required for making an informed permit decision. The permit application was deficient in the following areas: 1. The Pre - Construction Notification (PCN) indicates that there will be 74 linear feet of stream impact due to "excavation at the edge of Lanes Creek to install slope reinforcement ". The plans depict the use of "gabion mattresses" to provide the proposed slope reinforcement. A site visit indicates that the streambank proposed for excavation and reinforcement appears to be fairly - stable (including trees). It is unclear why this activity is necessary as the new bridge will be longer and provide additional floodplain availability for the stream. Additional floodplain availability will allow for energy dissipation on the floodplain rather than the streambanks. Provide information to support the request for the proposed 74 linear feet of stream impact: Additionally, if the need for the impact can be supported, DWQ does not typically authorize stabilization using gabions and would prefer a more natural method of streambank stabilization. Please provide an alternative form of streambank stabilization. i Therefore, pursuant to 15A NCAC 2H .0507(a)(5), we will have to place the permit modification request on hold until we are supplied with the necessary information. You have 21 days to respond in writing with the requested information or notification to this office that the information is forthcoming. Mooresville Regional Office Location: 610 East Center Ave., Suite 301 Mooresville, NC 28115 Phone: (704) 663 -16991 Fax: (704) 663 -60401 Customer Service: 1- 877 -623 -6748 Internet hgp:llportal.ncdenr.orglwebhva An Equal Opportunity 1 Affirmative Action Employer One NorthCarolina ;Vatnallry Dr. Gregory J. Thorpe Page Two If, at the end of the 21 days, this office has not received this information in writing, we will assume you are withdrawing your application and it will be returned. Furthermore, until the information is received by the NC Division of Water Quality, we request, by copy of this letter, that the US Army Corps of Engineers place the permit modification request on hold. If you have any questions or require additional information, please contact Polly Lespinasse at (704) 663 -1699. Sincerely, K-n 3l�- for Charles Wakild, P. E. Director cc: Sarah Hair, US Army Corps of Engineers, Asheville Field Office Michael Turchy, NCDOT PDEA Sonia Carrillo, NCDWQ Transportation Permitting Unit File Copy Co R. N w N A N N V N co N 10 0 W N -- — -- - - -- — -- --� Tr , A a z. r• to tt+ r �- loll, z oc 17 m 1 O�''e NC ems■ \: ��.a, t TL;L i v jI 1 I A a A A a O O 0 O O 1 1 a .1 O O 0 ip L m y�1 p C / 1j•�`, Fes. � OrQ A i , . f"h �i ifs mm T \— N