Blind Slough Restoration Project

Project Goal:

Restore tidal connection between the Columbia River Estuary and Blind Slough through the breaching of dikes, replacement and/or installation of culverts, installation of water control devices, and channel enhancement. Pre and post project monitoring of Blind Slough will determine project effectiveness in water quality improvement of Blind Slough's channel network as well as increased fish access to spawning and off-channel rearing habitat for salmonid species.

Project Abstract:

The Columbia River Estuary Study Taskforce (CREST), Clatsop Diking Improvement Company No. 7, with help from Portland District Army Corps of Engineers have prioritized the following array of restoration activities with the goal of enhancing historic hydrologic (figure 1) and bio-physical connection to the Columbia River Estuary. Restoration of these sites enhances water quality and reconnects seven (7) miles of habitat for aquatic species including migrating salmonids. Army Corps of Engineers provided necessary planning engineering and design that set the stage for on the ground construction work.

Figure 1: Historic Tidal Slough Structure of Blind Slough (~1870s, Coastal Survey Image)

Restoration Activities:

- Install 81 x 59 inch arch culvert and new water control structure at Aldrich Point. (#1)

- Install 5-60” culverts through railroad embankment. (#2) (Completed 2004)

- Excavate historic channel through Long Island Dairy property reconnecting Blind Slough to arm of Saspal Slough. (#3) (Scheduled for 2005)

- Install 48 inch culvert to restore connection to Saspal Slough. (#4)

- Install 2-5’ culverts to enhance channel connection at Leino Lane road crossing. (#5) (Scheduled for 2005)

- Breach dike crossing by installing 3-60” culverts with fish-friendly tidegates design (see photo). (#6) (Completed 2004)

- Install 48 inch culvert at Anderson road crossing. (#7)

In the past year (2004) CREST applied for funds with Bonneville Power Administration (BPA) and the Lower Columbia River Estuary Partnership (LCREP) to complete construction work at two (2) sites.(sites #2 and #6 below). Sites #3, #4, and #5 are slated for ’05 construction. CREST has conducted over 2 years of baseline monitoring to assess pre-construction water quality and fish population conditions. Monitoring will continue to assess changes to these parameters during critical migratory months and summer months. Funds contribute to a larger effectiveness monitoring program for the Columbia River Estuary.