Habitat Project Accomplishments
In this region, salmon and steelhead inhabit nearly 2,300 river miles throughout 17 subbasins and the estuary. It is estimated that habitat has declined anywhere from 30-90 percent.
While restoration of all lost habitat is neither practical nor necessary, success in recovering salmon will require both restoring degraded habitat as well as protecting functioning habitat.
Projects have been completed in just under half of the high-priority stream reaches (Tier 1 and Tier 2) in the region. Given funding constraints and the large area of the region, it is essential to identify where to continue to invest in habitat conservation and restoration to most effectively recover salmon and steelhead.
Estimated loss of habitat in the lower Columbia River tributaries and estuary
Following are the most common impacts to habitat conditions:
- Dams that require regulated streamflow or that block access to habitat
- Blocked passage due to failing culverts, tide gates, and other barriers
- Seasonal variations in high and low flows affecting water quality and temperature
- Loss of channel stability and migration corridors
- Limited off-channel spawning and rearing areas
- Loss of habitat complexity that is needed to meet the needs of fish during all their life stages and provide protection from predators
- Loss of nutrients that support juvenile survival
This information forms the basis for identifying priority protection and restoration needs. Referred to as Tier 1 and 2 reaches, these 575 highest priority reaches encompass 675 river miles and are the primary focus of restoration and protection work. To date, lower Columbia sponsors have implemented more than 800 projects using a variety of funding sources.