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Sep 03

SOUTH PRAIRIE CREEK PRESERVE PROJECT UPDATES

Posted on September 3, 2020 at 11:55 AM by Allan Warren

SPCP photoCold, clear groundwater fills the newly excavated side channel at the South Prairie Creek Preserve restoration site. The influx of groundwater is critical for keeping water temperatures from reaching levels lethal to salmonids during the summer. In the background, logs are staged for the more than 100 structures that will be placed in the banks and on the floodplain to provide roughness and help protect against erosion.

The salmon habitat improvement project at the District’s South Prairie Creek Preserve reached several important milestones over the past few months. Demolition of the former dairy buildings concluded in late spring, at which point work transitioned to the north floodplain. First, several large patches of poison hemlock were removed and buried to prevent spread of this harmful plant. Then a half-mile long side channel was excavated. Using the depression left by a relic side channel as a guide, this excavation daylighted cold, clear groundwater that quickly filled the new stream. More than 100 large wood structures have been installed on the floodplain and in the streambanks, followed by the installation of three channel-spanning structures in the mainstem of South Prairie Creek.

The bulk of construction is scheduled to wrap up by the end of summer, after which the focus will shift to completing restoration of riparian and floodplain plant communities across more than 36 acres.