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Rock Arch Rapids Fish Passage Cape Fear River Lock and Dam No.1 Bladen County, NC

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. Reason for Fish Passage. Mitigation for blasting to deepen Wilmington Harbor

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Rock Arch Rapids Fish Passage Cape Fear River Lock and Dam No.1 Bladen County, NC

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  1. Rock Arch Rapids Fish PassageCape Fear River Lock and Dam No.1Bladen County, NC US Army Corps of Engineers Wilmington District NC WATER RESOURCES CONGRESS Annual Meeting October 31, 2013

  2. 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

  3. Shortnose Sturgeon Acipenser brevirostrum Striped Bass Morone saxatilis North Carolina Anadromous Fish(Fish that spend most of their lives in saltwater but run up rivers to spawn)

  4. All Three Cape Fear River Locks and Dams Are Located in Bladen County, NC

  5. 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

  6. 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 • Short or long bypass channel – sturgeon not likely to find entrance • Fish lifts and ladders – high construction and maintenance cost and would clog with debris

  7. Rock Arch Rapids Conceptual Longitudinal Profile 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 Boulder vanes are located about every 8’’ change in elevation and are about 20 feet apart. 5-12” Rock fill FLOW 25:1 SLOPE DAM Adapted from Luther Aadland, MNDNR

  8. Rock Arch Rapids near CompletionCape Fear River, NC, Lock and Dam #1Average spring flow ~ 6,000 cfs ~2,000 cfs October 12, 2012

  9. Pre-ConstructionFish Passage Monitoring • Only available fish passage is via locking • Fixed and mobile sonic tag monitoring stations • Tagged 50 striped bass and American shad each of 4 years • 50 to 65% of the American shad and 50 to 77% of the striped bass passed Lock and Dam #1 • 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

  10. Post-Construction Fish Passage Monitoring • Passage via rock rapids, fish locking discontinued at L&D#1 • Interagency team developed 2-year post-construction monitoring plan. Monitoring collaborative effort lead by NCSU in the Spring of 2013 & 2014. • 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 • Similar to pre-construction monitoring using sonic tags to detect passage

  11. Monitoring Results & Future Actions • % tagged fish that passed Lock and Dam #1 in 2013 • 80% of Flathead Catfish Passed • 50% of American Shad Passed • However appeared to be more shad at L&D#2 • 21% of Striped Bass Passed • Results have been coordinated with all resource agencies • 2013 may not have been a representative year • Assess 2014 monitoring results before drawing conclusions on passage success

  12. Monitoring Results & Future Actions • Alternatives if 80% passage goal is not met in 2014 • Modify the rapids • Create several wider pathways for fish passage • Augment passage by reinitiating locking • If modifications necessary, continue monitoring to determine success • Optimistic that the rapids will meet success criteria

  13. Questions?

  14. Extra Slides if Needed

  15. Rock Arch Rapids near CompletionCape Fear River, NC, Lock and Dam #1Average spring flow ~ 6,000 cfs ~2,000 cfs October 12, 2012

  16. Construction and Cost • Construction Window • No spring in-water construction to avoid anadromous fish migration • Rock Rapids • Began June 2011 • Completed November 2012 • $13 million –filling 45’ deep scour hole, rapids and stabilizing lock wall

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