Blind Slough Restoration Project

Project Sponsors: Clatsop Diking Improvement Company # 7

U.S. Army Corps of Engineers

Columbia River Estuary Study Task Force

Nicolai-Wickiup Watershed Council

Blind Slough Project Location (RM 27)

Blind Slough Proximity and Connectivity to Cathlamet Bay

Problem Statement: Loss of Habitat Connectivity

 

Brownsmead: 1875 Brownsmead 1977

Source: Changes in Columbia River Estuary Habitat Types (D. Thomas, 1983)

Problem Statement: Historic Habitat Type Loss

0

10,000

20,000

30,000

40,000

50,000

Deep Water Medium Depth Shallows/Flats Tidal Marshes Tidal Swamps DevelopedFloodplain

Uplands -Natural and

Filled

Habitat Type

Acr

es

1870

1980

Source: Changes in Columbia River Estuary Habitat Types (D.Thomas, 1983)

Restore tidal connection to 7 miles of slough habitat between Blind Slough and the Columbia River Estuary by breaching the Blind Slough dike, replacement and/or

installation of culverts, and channel enhancement.

Project Goal

Blind Slough Restoration Activities

• #1 Aldrich Point Culvert

• #2 RR Crossing Culvert

• #3 Historic Channel Enhancement

• #4 Saspal Slough Culvert

• #5 Leino Lane Culvert

• #6 Breach Blind Slough Dike

• #7 Anderson Road Culvert

#1

#2

#3#4#5

#6 #7

Blind Slough Dike

 

. Pre and post project monitoring of Blind Slough will determine project

effectiveness in water quality improvement as well as increased access to spawning and off-channel rearing habitat for salmonid species.

Hypothesis #1-Water Quality: Increasing the intensity and extent of tidal exchange will enhance and/or modify water quality in three parameters: Temperature, Dissolved Oxygen, Salinity.

Hypothesis #2-Fish Use: Increasing the level of connectivity between Blind Slough's channel network and the Columbia River Estuary raises the probability of anadromous fish use for rearing, foraging, and spawning

Effectiveness Monitoring

2000 National Marine Fisheries Service FCRPS Biological Opinion

• The Corps is to play a lead role in developing and funding restoration projects with BPA primarily providing cost-share funding.

• Examples of “acceptable estuary habitat improvement” work that relate directly to Blind Slough Restoration include:  

• Breaching levees• Improving wetlands and aquatic plant communities• Enhancing moist soil and wooded wetland via better management of river

flows• Reestablishing flow patterns that have been altered by causeways• Creating shallow channels in inter-tidal areas• Enhancing connections between lakes, sloughs, side channels, and the

main channel

• Emphasizes the need to compile information to assess effectiveness of management activities.