Elwha River Engineered Logjam Monitoring Project

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Elwha River Engineered Logjam Monitoring Project

• Michael McHenry, Randall McCoy-Lower Elwha
  Klallam Tribe
• George Pess, Holly Coe, Martin Lierman-NOAA
  Fisheries
• Tim Abbe, Jennifer Goldsmith-Herrera
  Environmental
• Roger Peters-US Fish Wildlife Service

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Engineered Logjam (ELJ) Technology

• Based on the architecture of naturally occurring,
  stable log jams.
• Accommodate natural channel dynamics
  disturbance regimes.
• Meet traditional engineering standards while
  providing greater habitat value.
• Restore natural function and habitat complexity,
  recognize opportunities for entire system.
• Work within constraints of system (i.e., bridges,
  development).

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Meander Jam
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Bar Apex Jam
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EC

• RM 1.3-2.2
• Manage Flow Splits
• 21 ELJs (2000-2004)
• BAJ/Meander Types
• Distribute Flows
• Increase Habitat

HRC
SC-5
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Elwha ELJ Characteristics
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Study Design
Biological
Physical

• Stability
• Distribution of Flows
• Sediment
• Wood
• Habitat

• Primary productivity
• TOC/Chlorophyll a
• Secondary productivity
• Macroinvertebrates
• Juvenile fish
• Abundance
• Movement
• Adult Fish
• Redd mapping

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Peak Flows 1898-2004
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ELJ Performance

• 21 of 21 structures intact
• 20 of 21 have formed pools
• Net gain in LWD
• No significant decay
• Bank erosion reduced
• Various stages of revegetation

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Distribution of Flows

• Stage dependent
• Summer base flows lt25 cfs in east channel
• EC functioning as Ground Water SC
• Additional actions my be necessary to balance low
  flows

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Effects on Habitat Reach Scale
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Pool Development
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Pool Depth Frequency
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Temperature Effects
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1994
2006
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Reach Scale Sediment Storage
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Particle Size Distribution Change
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Visual Substrate Effects
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Spawning Habitat Created
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ALGAE ( OTHER ORGANIC MATTER)
NUTRIENTS
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Primary Productivity
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Primary Productivity
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Secondary Productivity
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Juvenile Fish

• Snorkel Observations
• Habitat Based
• ELJ v Non-ELJ
• Complex v Simple
• Analysis
• Proportion
• Density
• Biomass

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• Proportion
• Juvenile salmonid density was consistently
  greater in ELJ than non-ELJ bank units in 75
  species/size class categories.

Grey bar logjam units White bar non logjam
units
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• Density
• 50 of species/size class categories had
  consistently significant differences in densities
  due to habitat complexity.

white highly complex light grey moderately
complex dark grey low complexity
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• Biomass
• The greatest difference between ELJ and non-ELJ
  bank units occurred with biomass estimates.

Grey bar logjam units White bar non logjam
units
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• Season
• Biomass estimates exhibit a strong pattern of
  significant differences for juvenile, sub-adult,
  and resident salmonids during the summer.

white highly complex light grey moderately
complex dark grey low complexity
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Juvenile Fish Basic Conclusions

• The patterns suggest that the proportion of
  occurrence, median density and biomass of
  juvenile, sub-adult, and resident salmonids in
  bank units were positively influenced by ELJs.
• Statistical certainty was clouded by high
  variability in numbers, methods, and fish
  behavior.

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Wood Budget Redd Mapping
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Increasing Wood
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Local Sources Movement
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2001 LWD No Redd Data
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2001 LWD 2002 Redds
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2002 LWD 2002 Redds
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2002 LWD 2003 Redds
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2004 LWD 2003 Redds
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2004 LWD 2004 Redds
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2006 LWD 2006 Redds
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Conclusions

• All structures intact after 20 Bankfull Floods
• Positive changes in scour depth, sediment
  storage, substrate, temperature, bank erosion
  rates and flow patterns documented
• Primary production higher on ELJ surfaces
• Invertebrate production and diversity higher on
  ELJ surfaces
• Consistent differences observed for juvenile
  salmon (particularly proportion and biomass)
• Methods used in this study were not adequate to
  assess fish survival and productivity questions.

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Conclusions (cont.)

• ELJs can be an effective reach scale tool to
  manage sediment deposition and floodplain
  reconnection.
• ELJs can be an effective reach scale tool to
  manage chronic bank erosion.
• ELJs can be an effective reach scale tool tool
  to manage flow and therefore habitat area.
• Restoring large scale habitat forming processes
  (connectivity, floodplain forests, etc..) is key
  to the health of large rivers.

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Policy Gut Check

• effective river rehabilitation that produces
  lasting and fundamental changes in river
  integrity and biodiversity is going to be a long,
  hard and expensive operation. - Andrew Brooks
  (Geomorphology 79395-422)

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Thank You SRFB/IAC!

• Acknowledgements
• NOAA-Sarah Morley, Todd Bennett, Kris Kloehm,
  Peter Kiffney
• LEKT-Mel Elofson, Sonny Sampson, Ray Moses,
  Phillip Blackcrow, Jim Bolstrom, Roger Hopie,
  Keith Charles
• Sisson Family
• Four Seasons Engineering
• Wengler Surveying