Out with the Riprap: Colorado Gulch restoration will go a long way for Big Wood River floodplain habitat

To return the river to a more natural state, fallen trees will be used as woody debris in the river to improve trout habitat.
Published: Aug. 30, 2022 at 10:34 AM MDT
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HAILEY, Idaho (KMVT/KSVT) — In an effort in effort to reverse the bad practices that have been done in the past to the Big Wood River, floodplain and stream restoration work is being done at Colorado Gulch Preserve

“The Big Wood River has really suffered death of thousand cuts,” said Ryan Santo, Wood River Land and Trust.

He said the Wood River Land Trust has been working with Blaine County for the last four years to enhance floodplain habitat, and reconnect historic side channels that are approximately 1,200 feet of length, by removing rock rubble known as riprap along the banks.

“So right now, there are hundreds of cubic yards that were put in here that degrade habitat. it is a poor-quality fish habitat,” Santo said.

The approximately 1,300 cubic yards of riprap, and artificial fill, was originally put in to protect the Colorado Gulch Road and Bridge.

“Riprap does a lot of things. Less cover and less complex habitat for fish, and it also increases velocities,” said Santo.

Additionally, he said in 2017 the river won the battle with the riprap, when flooding compromised the Colorado Gulch Bridge.

“If you try to channelize or block the river from where it wants to go, it going to get there. So that was kind of a wakeup call for the need for that project,” Santo said.

To return the river to a more natural state, fallen trees will be used as woody debris in the river to improve trout habitat.

“Habitats associated with cover, largely debris, has eight to ten times more density of trout compared to habitat with riprap,” Santo said.

Part of the project will also entail relocating the old road along the river that was washed out in the flood of 2017.

“We are going to decommission this part and move it deeper in the floodplain so it will be easier to maintain,” said Santo

The $100,000 project, which is being largely funded by grants through FEMA; Blaine County Land, Water, and Wildlife Program; and the Trout and Salmon Foundation, The project is expected to be finished this week.

“So it’s a great refuge for people to come and recreate, access to fishing, access to trails, access to wildlife,” Santo said.