In-Stream Projects

In-stream projects are part of our larger Snake River Stewardship Program (SRSP) designed to improve water quality in the Snake River. Specifically, these projects narrow and deepen sections of the Snake River channel far upstream of the Hells Canyon Complex (HCC) by expanding seasonal floodplains adjacent to river islands. This increases water velocity and reduces heating by decreasing the surface area of the river during low summer flows.

We plant these expanded floodplains with native trees and shrubs such as willows, rabbitbrush, currants, native grasses and sedges to prevent erosion, provide shade and improve wetland habitat.

Our second project was completed in the fall of 2021, and we anticipate many more over the coming decades.

An illustration of how this type of island project narrows the river channel is shown below.

Images showing a before/after layout of the river around the islands, in which after the river is narrower and the floodplain expanded.

Download the image

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