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Published byDina Butler Modified over 9 years ago
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Horse Creek Damolition Presenters: Matt Stoecker, Stoecker Ecological and Thomas B. Dunklin Productions
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Horse Creek Santa Barbara
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Sisquoc River Steelhead Barrier Assessment and Recovery 2003 Funded by the Coastal Conservancy Identified migration barriers Historic steelhead documentation/current observations Habitat assessment Prioritize barriers for fish passage projects Funded by the Coastal Conservancy Identified migration barriers Historic steelhead documentation/current observations Habitat assessment Prioritize barriers for fish passage projects
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Key Findings Santa Maria R. was 2nd largest steelhead run in SB Co. Twitchell Dam (1950’s) blocked 264 miles, Cuyama R. Majority spawners used Sisquoc R. (Shapovalov, 1945) Over 203 miles historically accessible in Sisquoc River. Abundant high quality spawning and rearing habitat. Historic documentation and current wild O. mykiss population. 31 anthropogenic barriers identified, plus natural barriers. Horse Creek Dam blocks the most habitat at 19 miles Most limiting factor to Sisquoc steelhead is reduced surface flow for migration on the Santa Maria River caused by inadequate releases from Twitchell Dam and excessive groundwater withdrawal
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Historic Steelhead Documentation Sisquoc River 1916 (above) “ The stream is so full of mountain trout. I am confident that we saw in some places more than 500 at one sight….and had no difficulty capturing all we wanted with our hands.” Stephen Bowers 1879
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Current Steelhead Documentation
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Sisquoc R. Habitat
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Sisquoc R. Steelhead Survey 2005 Adult Steelhead over- summering 6 feet down in a cave under this bedrock ledge. Funded by DFG
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Looking up Horse Creek Canyon Dam Sisquoc River
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Horse Ck. Dam Built 11/3/1969 after Wellman Fire Sacrete bags on concrete footing, with re-bar Dam crest 62 feet Dam height 10 feet (5’ Dam, 5’ perched) Filled with sediment Stream gage, never used Built 11/3/1969 after Wellman Fire Sacrete bags on concrete footing, with re-bar Dam crest 62 feet Dam height 10 feet (5’ Dam, 5’ perched) Filled with sediment Stream gage, never used
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Horse Creek Habitat and Barriers 21.8 mi2, 1000-5000’ elev Dam 850 feet upstream from Sisquoc River 19 miles of habitat (poor to good) upstream of dam to natural barriers. Both perennial and intermittent reaches. No trout observed, Arroyo Chub present. 21.8 mi2, 1000-5000’ elev Dam 850 feet upstream from Sisquoc River 19 miles of habitat (poor to good) upstream of dam to natural barriers. Both perennial and intermittent reaches. No trout observed, Arroyo Chub present.
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Horse Ck. Upstream of the Dam
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Also Upstream in Horse Creek
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Channel Assessment Study 2005 Funded by American Rivers/NOAA Fisheries Michael Love and Assoc. and Stoecker Ecological Longitudinal Profile 2,200’ 7 channel cross sections 2 downstream, 1 at dam, 4 upstream Wolman pebble count of stored sediment 250’ u/s Funded by American Rivers/NOAA Fisheries Michael Love and Assoc. and Stoecker Ecological Longitudinal Profile 2,200’ 7 channel cross sections 2 downstream, 1 at dam, 4 upstream Wolman pebble count of stored sediment 250’ u/s
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Plan Map Longitudinal Profile Survey
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Sediment Deposit Upstream of Dam Horse Creek
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Cross Section at Dam
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Downstream Reference Channel
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Anticipated Removal Outcome Channel incision 2,321’ upstream 15,400 cubic yards of sediment u/s mobilized (Annual Sisquoc R. 255,000-367,000 yd3) 4-6% increase in one year, but will take more Sediment released relatively course (gravel and cobble) Wolman pebble count. Minimal to no negative impacts downstream Unobstructed wildlife/fish passage and improved habitat and surface flow upstream Channel incision 2,321’ upstream 15,400 cubic yards of sediment u/s mobilized (Annual Sisquoc R. 255,000-367,000 yd3) 4-6% increase in one year, but will take more Sediment released relatively course (gravel and cobble) Wolman pebble count. Minimal to no negative impacts downstream Unobstructed wildlife/fish passage and improved habitat and surface flow upstream
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The Preferred Alternative Removal Obsolete Not consistent with Wilderness and Wild Scenic management Most effective fish and wildlife passage Restore surface flows and channel complexity Inexpensive vs. fishway Removal Obsolete Not consistent with Wilderness and Wild Scenic management Most effective fish and wildlife passage Restore surface flows and channel complexity Inexpensive vs. fishway Explosives Staged release of sediment not necessary No danger to people Difficult access Inexpensive vs. heavy equipment Reduced impact to bank and channel DFG and CCC technical support and explosives (ammonium nitrate) available for project Interest in gaining experience/knowledge with this technique
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Detonation Cords Going Off
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Coastal Conservancy, Los Padres Nat. Forest, American Rivers, NOAA Fisheries, Dept. Fish and Game, California Conservation Corps, Community Environmental Council, Sisquoc Ranch, Thomas B. Dunklin Productions/Joan Dunning, Stoecker Ecological, Forest Watch
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Un-Dam it and they will come! Matt Stoecker Matt@StoeckerEcological.com Matt@StoeckerEcological.com Photo/Assistance thanks: Bob, Doug, Jim Stoecker Thomas Dunklin Michel Love Shaw Allen Kevin Cooper Tony Llanos Donna Toth Matt Stoecker Matt@StoeckerEcological.com Matt@StoeckerEcological.com Photo/Assistance thanks: Bob, Doug, Jim Stoecker Thomas Dunklin Michel Love Shaw Allen Kevin Cooper Tony Llanos Donna Toth
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