US Army Corps of Engineers BUILDING STRONG Rock Arch Rapids Fish Passage Cape Fear River Lock and Dam No.1 Bladen County, NC US Army Corps of Engineers Wilmington District NC WATER RESOURCES CONGRESS Annual Meeting October 31, 2013 BUILDING STRONG Reason for Fish Passage Mitigation for blasting to deepen Wilmington Harbor Major species of concern for blasting impacts: Endangered Shortnose & Atlantic Sturgeon Fish passage increases likelihood of sturgeon reaching their traditional spawning sites upstream of Fayetteville and thus increasing population 2 BUILDING STRONG North Carolina Anadromous Fish (Fish that spend most of their lives in saltwater but run up rivers to spawn) Shortnose Sturgeon Acipenser brevirostrum Striped Bass Morone saxatilis 3 BUILDING STRONG All Three Cape Fear River Locks and Dams Are Located in Bladen County, NC 4 BUILDING STRONG Fish Passage Coordination Numerous on and offsite meetings and conference calls Consensus reached on rock arch rapids alternative Dr. Luther Aadland (MNDNR) involved in design and construction of more than 40 rapids including Lock and Dam # 1 5 BUILDING STRONG Fish Passage Alternatives Removal of lock and dam precludes navigation and public water supply Modify existing locking procedures already optimized Rock arch rapids across the dam selected alternative Other alternatives o Short or long bypass channel sturgeon not likely to find entrance o Fish lifts and ladders high construction and maintenance cost and would clog with debris 6 BUILDING STRONG DAM 2 to 3 diameter wearing/armor stone: Stones sized according to maximum shear stress in rapids 4 to 6 diameter boulder weirs/vanes: Boulders sized to resist movement due to debris 25:1 SLOPE Conceptual Longitudinal Profile Rock Arch Rapids FLOW Boulder vanes are located about every 8 change in elevation and are about 20 feet apart. Adapted from Luther Aadland, MNDNR 5-12 Rock fill 7 BUILDING STRONG Rock Arch Rapids near Completion Cape Fear River, NC, Lock and Dam #1 Average spring flow ~ 6,000 cfs 8 ~2,000 cfs October 12, 2012 BUILDING STRONG Pre-Construction Fish Passage Monitoring Only available fish passage is via locking o Fixed and mobile sonic tag monitoring stations o Tagged 50 striped bass and American shad each of 4 years o 50 to 65% of the American shad and 50 to 77% of the striped bass passed Lock and Dam #1 o Only 35% of the American shad and 25% of the striped bass passed all three locks and dams to reach their traditional spawning grounds above Fayetteville Too few sturgeon available 9 BUILDING STRONG Post-Construction Fish Passage Monitoring Passage via rock rapids, fish locking discontinued at L&D#1 o Interagency team developed 2-year post-construction monitoring plan. Monitoring collaborative effort lead by NCSU in the Spring of 2013 & NCDWR, NCWRC, NCDMF, NMFS, USFWS, Corps Goal: Minimum 80 percent passage of American shad, striped bass and flathead catfish pass Lock and Dam #1. Passage success = # fish that pass the dam/ # of fish that approach the dam, e.g. 40/50x100%=80% passage Too few sturgeon to assess passage - flathead catfish used instead o Similar to pre-construction monitoring using sonic tags to detect passage 10 BUILDING STRONG Monitoring Results & Future Actions % tagged fish that passed Lock and Dam #1 in 2013 o 80% of Flathead Catfish Passed o 50% of American Shad Passed However appeared to be more shad at L&D#2 o 21% of Striped Bass Passed o Results have been coordinated with all resource agencies 2013 may not have been a representative year o Assess 2014 monitoring results before drawing conclusions on passage success 11 BUILDING STRONG Monitoring Results & Future Actions Alternatives if 80% passage goal is not met in 2014 o Modify the rapids Create several wider pathways for fish passage o Augment passage by reinitiating locking If modifications necessary, continue monitoring to determine success Optimistic that the rapids will meet success criteria 12 BUILDING STRONG Questions? 13 BUILDING STRONG Extra Slides if Needed 14 BUILDING STRONG Rock Arch Rapids near Completion Cape Fear River, NC, Lock and Dam #1 Average spring flow ~ 6,000 cfs 15 ~2,000 cfs October 12, 2012 BUILDING STRONG Construction and Cost Construction Window o No spring in-water construction to avoid anadromous fish migration Rock Rapids o Began June 2011 o Completed November 2012 $13 million filling 45 deep scour hole, rapids and stabilizing lock wall 16