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HomeMy WebLinkAbout2022-03-23_BR-0076_Status_Mtg_03_Summary BR-0076: NCDOT/Agencies Status Meeting– 3/23/22 Meeting Summary Bridge No. 9 on NC 28 over Little Tennessee River Division 14 – Graham/Swain County Line, NC March 30, 2022 This summary covers the 3rd in a series of recurring meetings which took place 3/23/22 at 1:00 p.m. via Microsoft TEAMS. PARTICIPANTS: Josh Deyton NCDOT - Division 14- Project Development Team Lead Stacy Oberhausen NCDOT/TGS – Division 14 – Project Manager Brenna Copeland NCDOT – EAU- Bio Surveys Justin Johnson Brookfield Renewables –Public Safety Kevin Mitchell NC DEQ, Division of Water Resources – Environmental Specialist Robert Patterson NC DEQ, Transportation Permitting – Stormwater Engineer Holland Youngman USFWS – Wildlife Biologist David McHenry NCWRC – Western DOT Coordinator Randy Henegar TGS - GESC Hydraulic Review Jay Twisdale TGS – GESC Hydraulic Review Cathy Houser RK&K – Roadway / Project Manager – Design Phase Jon Whittington RK&K – Hydraulics and Erosion Control John Williams RK&K – Planning / Project Manager – Planning Phase NCDOT Hydraulics Guidelines – Deck Drains As of February 2022, NCDOT has updated its Hydraulic Guidelines and no longer require Deck Drains but still allows for the consideration of no deck drains if special circumstances warrant it. It uses a program developed by USGS and NCDOT nicknamed NC SELDM (North Carolina Stochastic Empirical Loading and Dilution Model) to assess potential impacts of highway runoff. The model was run for this particular site and resulted in low impact from runoff. Deck drains on this bridge would require an additional 2 feet of bridge width at a cost $220,000. NCDOT would like to host a discussion with NCDWR and any other interested agencies to determine if deck drains over the water are an appropriate measure at this site. The following expressed interest in the discussion: • Kevin Mitchell NCDWR • Robert Patterson NCDWR • Holland Youngman USFWS • Dustin Johnson Brookfield Renewables • Ashley Thomas Brookfield Renewables BR-0076: NCDOT/Agencies Status Meeting– 3/23/22 Meeting Summary Bridge No. 9 on NC 28 over Little Tennessee River Division 14 – Graham/Swain County Line, NC Causeways – Hydraulic Analysis and Desired Discussion The impact of proposed causeways on the flow regime is a concern that was identified early in the process, as a result, a hydraulic analysis of the causeways was completed. TVA’s flow data checked to 2004 and a majority of the flowrates do not exceed 10,000 cfs. There are four phases of causeway blockage, the most constricted is Phase III at 84% blockage. A meeting with TVA and other interested parties to discuss this flowrate will be held. The following agencies were identified to participate in the meeting with TVA: • Dustin Johnson Brookfield Renewables • Ashley Thomas Brookfield Renewables • John Norris Brookfield Water Resource Manager • Dave McHenry NCWRC • Nick Shaver NCWRC – Land and Water Access – Mountain Region Supervisor • Kevin Mitchell NCDWR We are considering adding pipes to the causeway to increase flow. The pipes are a concern from a recreational standpoint; however, through coordination with NCWRC’s Nick Shaver, the plan is to temporarily block navigation through this area during construction. The group was polled as to what topics they want addressed at the meeting and the following were identified: • Velocities through the constriction? (Dave McHenry) • Potential for degradation? (Kevin Mitchell) • Public Safety? (Dustin Johnson) • Is TVA ok with their Boat Ramp being closed? (Dave McHenry) • Timing of causeway placement? Next Steps A doodle poll will be sent out to identify dates for the two meetings referenced above. NCDOT will be prepared for the questions identified above.