DESCRIPTION
Kittitas County Conservation District used this funding for a riparian restoration demonstration project on a site along lower Wilson Creek, near Ellensburg. The project area had sparse Pacific willow, cottonwood, and shrub species but was dominated by reed canary grass. This project worked to establish shrub and tree species to provide shading, leaf litter and woody debris to the stream in aid of salmonid recovery. The SRFB, BPA, Yakama Nation, Kittitas County Conservation District (KCCD), and WDFW have invested heavily in fish screening and passage on the lower eight miles of Wilson Creek; however, a more functional riparian zone would help optimize the benefit of the re-connected upstream passage.
At stream mile 6 on Wilson Creek, the existing cover of reed canary grass was subjected to treatment and then re-vegetated. The project was designed to be educational for landowners and natural resource managers.
Lessons learned included the following:
· Herbicides containing Imazapyr are a very potent tool to treat riparian areas overgrown with reed canary grass. In the arid climate of the project area, herbicides containing Imazapyr persist longer than stated on the label. It would be better to wait 1 to 3 years prior to planting trees and shrubs into the treated area.
· Herbicides containing Glyphosate do not have a long term effect on their treatment areas. Trees and shrubs can be planted soon after treatment. These areas, however, require follow-up maintenance to control the noxious weed invasion.
· Neither herbicide is effective in controlling reed canary grass in the perennially wet areas immediately next to the stream, especially if those areas are artificially flooded late in the growing season due to irrigation tailwater. In these areas it is more effective to cover the reed canary grass with a fabric mulch and to plant cuttings of riparian trees and shrubs directly through the fabric mulch.