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1/27/2017
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Jeff MuirheadStantec Consulting, Ltd.
September 26, 2016
The “Threshold” of Habitat:Spawning Salmon in a Restored Threshold Stream
Outline
1 The What, Why, and How of Threshold Channels
2 Case Study: Oshawa Creek
3 Summary and Next Steps
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The What, Why, and How of Threshold Channels1
Credit River Tributary at Chinguacousy Road, ON
What is a Threshold Channel?
The What, Why, and How of Threshold Channels
“…a channel in which movement of the channel boundary is negligible during the design flow.”
-USDA (2007), Chapter 8, National Engineering Handbook
i.e., Watercourses which maintain their pattern and profile due to large, erosion resistant particles and established vegetation
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The What, Why, and How of Threshold Channels
Why do we use Threshold Channels?
1. Restrictions on the areas available for stream restoration
The What, Why, and How of Threshold Channels
Why do we use Threshold Channels?
1. Restrictions on the areas available for stream restoration
2. Limited sediment supply (i.e., “sediment starved” systems)
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The What, Why, and How of Threshold Channels
How do we design and build Threshold Channels?
INSTREAM STRUCTURES
The What, Why, and How of Threshold Channels
How do we design and build Threshold Channels?
Augmented Riffle
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The What, Why, and How of Threshold Channels
How do we design and build Threshold Channels?
Log and Boulder Constructed Riffle
The What, Why, and How of Threshold Channels
How do we design and build Threshold Channels?
Log Step Pool Structure
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The What, Why, and How of Threshold Channels
How do we design and build Threshold Channels?
Wood Debris Toe Protection, Live Stakes, and Vegetation Transplants
The What, Why, and How of Threshold Channels
But, do Threshold Channels “work” for those who use it
most?!
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Case Study – Oshawa Creek2
Case Study: Oshawa Creek
Oshawa Creek at Conlin Road
Lake Ontario
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Case Study: Oshawa Creek
• Channel realignment associated with proposed road widening
Oshawa Creek
Case Study: Oshawa CreekExisting Conditions – some issues…Existing Conditions – some issues…but not that bad!
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Case Study: Oshawa CreekStream Design
Wood Debris Toe Protection
Augmented Riffle
Log and Boulder Constructed Riffle
2004 – Existing Conditions2013 – Pre-Construction2014 – Construction I2014 – Construction II2015 – Post-Construction
Case Study: Oshawa CreekProject Sequence
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Case Study: Oshawa CreekRestored Stream
Fish!Year 2 – Wood Toe Wash-Out1. No Construction Administration
by Stream Personnel During Construction
2. No As-Built Survey Completed?
Case Study: Oshawa CreekBuild it (properly…) and they will come!
September, 2015
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Summary and Next Steps3
Summary and Next Steps
Threshold channels can work for fish passage
and spawning
Designs work when integrated teams of biologists, engineers, and geomorphologists work
together
Bio
Eng Geo
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Questions?
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