Upper Tee Meadow Restoration Project

The Upper Tee Meadow Restoration and Passage Barrier Removal Project is located in Latah County, Idaho on the East Fork of Corral Creek in the Potlatch Watershed. The project has sucessfully connected 16.4 acres of floodplain to a restored sinuous historic channel of Upper Corral Creek and opened up 2.44 stream miles above a culvert on Vassar road which was previously a passage barrier to endangered steelhead. The improved meadow hydrology is improving infiltration and storage of water in the meadow and resulting in an increase in late-season cool base flow releases into the channel and extending the wetted days in this intermitant reach and downstream. Installation of native riparian woody plants will create shade, stabilize banks, provide overhanging root masses, improve future LWD recruitment, and improve the local food web.

The severely incised channel/ditch that conveyed flow was plugged intermittently with a series of six ditch plugs to create wetland cells to retain spring flood flows throughout the growing season and provide hyporheic flow across the meadow. A new channel was cut using historic channel scars as guidelines and pools, habitat structures, and log jams were placed to improve channel diversity and habitat. A section of railroad berm was regraded to improve floodplain connectivity with the existing high value vegetation from the top of the berm scraped off and set back down in place after removing the excess soil from beneath. All disturbed ground was stabilized with the installation of microtopography, slash, logs, native seed, and mulch before the first autumn snowfall. Containerized plants, poles, and plugs of trees, shrubs, forbs, grasses, and grass-like plants were used to fill in bare ground, stabilize vulnerable areas, and stock the riparian corridor along the new channel and wetland cells. At the lower end of the project site the existing undersized passage barrier culvert was replaced by an arched culvert lined with cobble. A barbed wire livestock exclusion fence was installed.

Throughout the extremely dry summer and fall of 2021 (classified as exceptional drought in Latah County from July through December 2021 by the USDM) the area around the wetland cells remained green and the soils saturated. A small amount of water remained in most of the cells throughout the year.

Adaptive management in 2020 and 2021 (post-construction) led to the installation of more (than proposed) in-stream log jams to reduce down cutting and encourage sedimentation in vulnerable areas in the newly constructed channel. Construction implementation was under budget so a budget reduction of $90,000 was requested and approved in 2021.

This project will restore hydration of the meadow complex, increase the amount of groundwater stored, improve hyporheic water exchange, extend base flows, and enhance meadow/riparian vegetation all of which will improve downstream steelhead habitat. Potlatch River is a major spawning area for the ESA-listed Clearwater River lower mainstem steelhead population of the Clearwater Major Population Group in the Snake River steelhead Distinct Population Unit. The Corral Creek watershed is a subwatershed of the Potlatch River and is ESA-designated critical habitat. The process-based restoration proposed represent priority actions in a priority watershed (Potlatch River) as directed by the NMFS 2017 ESA Recovery Plan for Snake River Idaho Spring/Summer Chinook Salmon (Oncorhynchus tshawytscha) and Steelhead (Oncorhynchus mykiss) Populations.