Chewuch Diversion Dam Renovation

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Chewuch Diversion Dam Renovation

• Managing an Innovative Design and Multiple
  Partners

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Project Information

• Project Sponsor Chewuch Basin Council (Chris
  Johnson Project Manager).
• Partners Reclamation, WDFW, BPA, USFWS, Chewuch
  Canal Company, Methow Salmon Recovery Foundation,
  USFS .

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Project Location
Chewuch Dam
Chewuch Dam
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Other Information

• Existing dam was a low flow passage impediment
  to Upper Columbia steelhead, Upper Columbia
  spring Chinook, and bull trout. (All ESA listed
  species)
• Spring Chinook were spawning in 700 inlet canal

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Project Finances

• Project Cost - 513,770
• Funding Sources
• SRFB Grants 204,670
• FRIMA grant - 74,400
• BPA - 149,400
• Douglas PUD 43,300
• Private Sources-42,000

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Project Benefits

• Only two passage impediments on Chewuch River
  Chewuch and Fulton Dams.
• This project opened approximately 50 R.M. to
  unimpeded low flow passage.
• Eliminated dewatered Chinook redds in inlet
  canal.

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Project History

• Reconstructed in the 50s Chewuch Dam was
  undermined and failing.
• Fish ladder was stranded at low flows.
• Identified as a partial passage barrier (USFS,
  WDWF)
• Consistent with Limiting Factors Report and draft
  UCSRP

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Project History

• 2003 - Chewuch Canal Company contacts
  Reclamation for design work
• 2004 - Chewuch Basin Council begins funding and
  project management assistance for CCC

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Project Design

• Reclamation designers developed 7 alternatives
  (including rock v-weirs) Engineers from WDFW,
  NOAA Fisheries, and USFWS were consulted during
  Reclamations 1/4ly coordination process.
• Permitting through coordinated Reclamation process

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Project Implementation

• Bid Process Open competitive bid
• Contractor Boulder Creek Excavating
• Materials Rock from USFS lands
• Construction Oversight Reclamation under BPA
  contract.

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Project Implementation

• Construction from Oct.1, 2005 to January 15,
  2006. (Punch List in 2006)

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Finished Product

• 5 roughened channel 96 long
• New dam crest 12 higher to eliminate flashboards
  except during extreme low flows.
• Operable headgate to prevent unregulated flows
  down inlet canal
• Adult fish exclusion to prevent spawning in inlet
  canal
• Over 200 spring Chinook redds above the structure
  in 2006
• Didson camera monitoring by USGS showed adult
  fish passing structure

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A Reality Test - High flows 2006

• Over 6000 c.f.s. a 13 year event.

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After the Flood.
April 2006
July 2006
Hand Maintenance
August 2006
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Current Condition
March 2007 Flows at 700 cfs /-
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Ongoing Monitoring/ Adaptive Management

• Measurements of roughened channel profiles
• Upstream redd counts
• Didson camera
• Adaptive management

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Management Lessons Learned

• Understand your liability
• Identify contingency funding sources before you
  start
• Permit review and consultation need to be started
  during the design process

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Construction Lessons Learned

• When you play with sticks and stones in the river
  never assume one and done
• Leave spare parts
• If possible, leave your permits and funding open
  for at least one high water event.
• Be forthright up front with owners about their
  long and short term maintenance responsibilities.

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Questions?
By the way, if you were wondering what happened
to the other barrier.
Fulton was completed this winter as a full span
roughened channel opening unimpeded passage to
the entire Chewuch River.