Contract Description:
Introduction
The Woodlee Restoration Project is located on the Upper Grande Ronde River, tributaries to the Snake River. The project is located on 1.25 miles of the upper Grande Ronde River (RM 198-199). The project is located within Upper Grande Ronde River (1706010401); Meadowbrook Creek (170601040103) watersheds. The Upper Grande Ronde River is spawning and rearing habitat for Snake River Basin summer steelhead, Snake RiverBasin spring chinook salmon, bull trout and redband trout. Historic beaver trapping, mining, roading and the Woodlee Campground created a confined channel, with limited floodplain interaction and diminished deciduous vegetation.
The Woodlee reach of the upper Grande Ronde River and its meadow habitats are not in proper functioning ecological condition (hydrologic, geomorphic, vegetative composition), due to historic management that included beaver trapping, mining, roading and the Woodlee Campground.
The project would prioritize LWD placement to add roughness, increase floodplain interaction and habitat complexity, promote out of channel flooding and activate 1.25 miles of side channels. It is expected that the project will promote longer periods of hydrologic production, decreased stream temperatures, increased low velocity habitat, increased fish cover and increased riparian deciduous vegetation. The project would place wood within 1.25 miles of the upper Grande Ronde River and 1.25 miles of side channels, plant 4,000 deciduous seedlings and 10,000 cuttings. Project partners include: Grande Ronde Model Watershed, Bonneville Power Administration, and the US Forest Service.
Issues
Floodplain form and function: The Woodlee reach has limited water capture and retention capacities due to past anthropogenic influences. These deficiencies have lowered ground tables. This has resulted in lower riparian vegetation survival and vigor, a decreased ability to store water and buffer water temperature, less connection to the floodplain to moderate in-channel velocity, and lower quality salmon habitat. Lack of floodplain form and function has resulted in:
* Decrease in water storage and meadow/wetland habitats resulting in drier site and mesic-site species encroachment. Drier sites are less conducive to riparian deciduous woody vegetation species (Populous and Salix) that are important food and habitat for beaver populations.
* Potential increase of in-stream water temperatures from decrease in groundwater recharge, which can be problematic for salmonids.
* Increase of in-channel velocity where the channel has downcut, and doesn't spread water out onto the floodplain during high flows. The process of downcutting causes vertical erosion, which increases fine sediment levels and decreases habitat complexity.
* Decrease in the amount of zero velocity habitat, which provide juvenile salmonids protection, temperature buffering, food sources and feeding areas, and resting areas.
Side channel habitat and activation: There are 1.25 miles of old channel scrolls within the floodplain that are rarely activated, due to many of the issues identified above.
* Channel incision and lack of woody debris have isolated 1.25 miles of side channel scrolls from the existing channel. These channels only flow during high flow events.
Fish habitat complexity: The Woodlee Reach's fish habitat complexity (cover, pool quality/quantity, and zero velocity habitat) is limited.
• Channel incision and lack of instream woody material has affected the quantity and quality of spawning, rearing, and overwintering habitat in the Woodlee Reach.
Objectives
Specific Actions
Restore Hydrologic Function - Increase hydration of a laterally confined channel to improve groundwater retention through channel spanning log jam construction.
Activate 1.25 Miles of Side Channel Scrolls - Encourage and create perennial side channels through channel spanning log jam construction.
Improve Fish Habitat - Restore habitat complexity. Existing LWD structures will be modified and additional whole trees will be placed. These structures will encourage scour pool habitat, and fish cover.
Benefits
Approximately, 1.25 miles of side channels will be activated through constructing woody debris jams in strategic locations to raise water levels that would engage existing side channel scrolls.
* Floodplain engagement will increase through constructing woody debris jams in strategic locations to raise water levels.
* Deciduous riparian vegetation would increase through planting and increased survival/natural recruitment through raised water tables.
* Habitat complexity and pool quality will improve through woody debris jam construction.