Bellevue Reach River Restoration
WORKING TOGETHER FOR A HEALTHIER BIG WOOD RIVER IN BELLEVUE​
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This is a great example of taking a reach-wide look at river restoration by using a collaborative approach working with a diverse group of stakeholders. For years stakeholders would harden the banks of the river with riprap to protect homes and other critical infrastructure degrading fish habitat and natural river processes. This has created a “ping-pong” effect pushing flood flows to each side of the river. In 2019 the WRLT brought stakeholders together to find flood mitigation efforts that would protect infrastructure but would also enhance fish habitat and natural river processes. We would like to thank our partners below!
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City of Bellevue
Trout Unlimited
Private Homeowners
Friends of the Howard Preserve
District 45 Board of Controls
Flood Control District #9
BELLEVUE REACH SUB PROJECTS
1. BANK STABILIZATION AND ENHANCEMENT - FEB 2020
2. LOWER HOWARD PRESERVE - MARCH 2021
3. BELLEVUE SIDE CHANNEL ENHANCEMENT - MARCH/APRIL 2021
4. D45 HEAD DAM - SUMMER/FALL 2023
5. MID-BANK STABILIZATION AND ENHANCEMENT PLANNING
6. UPPER SIDE CHANNEL ENHANCEMENT & LEVEE SETBACK - NOT FEASIBLE
Coming Soon
We would like to express our deepest condolences to the family of Archie Bouttier. Archie was a major stakeholder and supporter for this project. His empirical knowledge of the Big Wood River helped shape the design of this project and we could not have done this without the efforts from Archie. He will be missed.
ABOUT THE RESTORATION
This project is part of a mile-long design from Broadford Bridge down to Riverside Estates on the Big Wood River. A large stakeholder group consisting of City of Bellevue, Flood Control District #9, Diversion 45 Canal District, Friends of the Howard Preserve, several private landowners, Trout Unlimited and Wood River Land Trust, all contributed funds to this design.
The purpose of the design was to find flood mitigation solutions for private property and enhance floodplain and natural fluvial processes.
An additional 1,700’ of side channel habitat gets added to Big Wood River! Outstanding news for spawning trout!
PROJECT GOALS & BENEFITS
We are breaking ground on another river restoration project this month! We will be reactivating and enhancing two historic side channels of the Big Wood River. This project is taking place on private property in Bellevue, just below the south end of the Howard Preserve. There will not be any preserve or trail closures during the restoration process.
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Excavating and improving the side channels will encourage flood conveyance at lower flows, providing flood mitigation, reconnecting floodplain, enhancing natural fluvial processes, and providing habitat for trout and other wildlife species. Side channels offer vital complex spawning and rearing habitat for salmonid species and allow fish to escape high velocity flows. The upstream floodplain side channel inlet will incorporate a large woody debris jam, providing additional habitat cover and promoting channel stability. This project is the next step in a larger design to restore a mile-long stretch of the Bellevue reach of the Big Wood River. In 2020 the Land Trust completed a bank stabilization project above Howard Preserve, and in 2021 another side channel restoration project was completed at Lower Howard Preserve. The next step in the design will take place later this year on the District 45 diversion canal dam.
PROBLEMS & LIMITING FACTORS
In this stretch of the Big Wood, residences and property owners have been trying to mitigate flooding impacts for decades with small-scale individual projects. Private landowners have incurred heavy costs caused by flood flows mostly due to land lost from erosion. One landowner next to the project area spent $119,562 due to damages of property from 2017 flood flows. Funds from this resident were spent on emergency bank protection and property reclamation work. Another neighboring landowner lost approximately 2 acres of developable land and spent $22,425 on emergency rip-rap to protect property in 2017. Immediately upstream of the Riverside Estates neighborhood is a tight meander geometry of the river that posed a threat to the Diversion 45 canal in 2017 and required emergency rip-rap for protection.
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The Big Wood River Atlas identified the reach adjacent to the City of Bellevue as having the second largest FEMA floodplain width, yet being 44% covered in bank hardening treatments. It is apparent this stretch is prone to flooding, but is unable to experience lateral expansion. The active channel has shifted many times here, preventing stable riparian succession. The 2017 flood resulted in a heavy amount of sediment aggradation within project reach, limiting flood conveyance capacity and viable high flow refuge for trout.
DIVISION 45 HEAD DAM PROJECT
Trout Unlimited has partnered with WRLT to modify the Diversion 45 canal head dam. Currently, the head dam is a fish passage barrier at lower flows and the artificial rise in the river holds back sediment which is making the river laterally unstable, increasing erosion and increasing incision downstream, which is further disconnecting the river from its floodplain. The head dam will be modified to allow fish passage at all flows and create an equilibrium of sediment transport capacity to enhance habitat.
Coming Soon
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