Latah Soil and Water Conservation District

Completed Project - Corral Creek - Avulsion Round Meadow Reach Project Summary

Completed Project - Corral Creek - Avulsion Round Meadow Reach Project Summary

Project Title

Corral Creek Wetland and Riparian Restoration: Avulsion / Round Meadow Restoration Project

 

Project Type

Steelhead Habitat Restoration

 

Project Location

Corral Creek, a tributary of the Potlatch River, in Latah County, Idaho

 

Watershed Information and Limiting Factors

Corral Creek subwatershed is 14,300 acres, approximately 4 percent of the Potlatch River Watershed, and includes predominantly forested and canyon stream types. Corral Creek supports spawning and rearing habitat for ESA-listed threatened steelhead trout (Oncorhynchus mykiss).  Limiting factors include: high water temperature, high flashy stream flows, low summer base flows, lack of complexity in stream composition, migration barriers, and sedimentation (Resource Planning Unlimited 2007).

 

Ownership

Private land

 

Project Supporters

Landowner (access and minimum 20 percent project match)

Bonneville Power Administration

Idaho Office of Species Conservation / Pacific Coast Salmon Recovery Fund

Idaho Department of Environmental Quality / EPA Clean Water Act Funding

 

Project Description

Problem:  Limiting factors affecting steelhead habitat: high water temperature, high flashy stream flows, low summer base flows, lack of complexity in stream composition, and sedimentation. Low flow conditions during rearing, in particular, limit productivity. Legacy effects of logging, with associated construction of railroad spur lines, and livestock grazing, had degraded water quality, impaired hydrology, and reduced pool habitat. After a passage barrier downstream was removed in 2007, spawning steelhead trout regained access to the upper Corral Creek watershed, including this reach (Bowersox pers comm). Improvement and expansion of spawning and rearing habitat for steelhead trout is a priority in the Potlatch River watershed (Ecovista 2003, Resource Planning Unlimited 2007). Low flow conditions during rearing, in particular, limit productivity. Between 2005 and 2008, Corral Creek in the Avulsion Reach experienced erosion events that allowed the flow to be diverted from the narrow, sinuous, well-vegetated historic channel in to the ditch of an old road bed associated with early 20th century logging. In Round Meadow, upstream of the Avulsion location, the flow had already been captured in borrow ditches associated with the temporary rail lines known as shay lines, which were used to transport logs. The straight, wide ditch sections enabled higher flow velocities, causing ongoing bank and bed erosion, adding sediment and degrading downstream water quality, and allowing the flow to exit the system more rapidly than historic conditions.

Solution:  Address limiting factors by returning flow to sinuous, well-vegetated channel to reduce erosion, improve stream composition and shading, and restore meadow hydrology to attenuate flashy peak flows, improve summer base flows, and reduce water temperature in pools through groundwater seepage. In 2008 we began construction of channel plugs to divert the flow back into the shallower, more sinuous historic channel to slow the flow through the meadow, increase hydration of the meadow, decrease erosion, and improve wetland habitat. By diverting flow back into the historic channel, instream pool frequency and pool habitat complexity for steelhead trout was immediately improved. In order to reduce erosion pressure on the main diversion channel plug, we diverted flow of a minor tributary northward by cutting in a new channel. The ditch at Avulsion Reach was converted to a series of wetland cells, to further enhance infiltration. Following completion of instream construction, all bare areas were seeded and mulched, or seeded, mulched and covered with erosion control material, to stabilize the soil and prevent erosion. The seed consisted of a mix of native grasses and forbs. The mulch is a weed-free pelletized straw product. Disturbed areas were also planted with a mix of native sedges, rushes, bulrushes, forbs, and woody species. From 2008 through 2013, over 12,500 containerized plants and whips have been planted to re-establish vegetation in disturbed areas and to enhance the riparian zone vegetation in undisturbed sections. Livestock fencing installed in 2009 excludes cattle from the restoration area to allow establishment of the native vegetation and recovery of the meadow vegetation. A livestock water pond was constructed in late 2011 to provide alternative water for the cattle and to draw them upslope and away from the meadow to reduce compaction. The off-channel water also reduces bank trampling and improves riparian vegetation along portions of the creek that remain unfenced.  Photo points were established to document changes in vegetation, and survival monitoring will identify replanting needs (Latah SWCD 2013).

 

Status:  Complete

Instream construction was completed in 2008.  Minor repair work and revegetation were completed in 2009 and 2012. The solar-powered watering system for the livestock pond was installed in June 2013. Other than minor additional revegetation, as needed, the project work is complete. Function of the structures will continue to be monitored for several years.

 

References

 

Ecovista. 2003. Clearwater Subbasin Assessment. Prepared for Nez Perce Tribe Watershed Division, in cooperation with the Clearwater Policy Advisory Committee. www.nwcouncil.org

 

Latah SWCD (Latah Soil and Water Conservation District). 2013. Monitoring Plan and Procedures, Draft.  Moscow, ID.

 

Resource Planning Unlimited. 2007.  Potlatch River Watershed Management Plan. Sponsored by Latah Soil and Water Conservation District. Moscow, ID.  www.latahsoil.org/id50.html

Summary prepared by Trish Heekin, Resource Conservation Planner, Latah Soil and Water Conservation District, 2014

Latah Soil and Water Conservation District
Gritman Medical Park (Federal Building)
220 East 5th Street, Suite 208
Moscow, Idaho 83843
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