A total of 57 Western Subbasin streams were designated as salmonid refugia areas and were rated into one of the four refugia categories. Refugia categories were defined as:
High Quality – relatively undisturbed habitat, with the range and variability of conditions necessary to support species diversity and natural salmonid production;
High Potential – diminished but good quality habitat with salmonids present, currently managed to protect natural resources with the possibility to become high quality refugia;
Medium Potential – degraded or fragmented instream and riparian habitat, with salmonids present but reduced densities and age class representation. Habitat may improve with modified management practices and restoration efforts;
Low Quality – highly impaired riparian and instream habitat with few salmonids (species, life stages, and year classes). Current management practices and conditions have significantly altered the natural ecosystem and major changes are required to improve habitat.
The most complete data available in the Western Subbasin were for tributaries surveyed by CDFW. However, many of these tributaries were still lacking data for some factors considered. Five streams were rated as high quality refugia, 38 as high potential refugia, 12 as medium potential refugia, and 2 as low quality refugia habitat.
Three of the largest streams in the subbasin were divided into two sections because of significant differences in conditions and salmonid use between lower and upper areas:
Hollow Tree Creek - the area below the old hatchery (downstream from the confluence of South Fork Creek) was rated medium potential, and the area above the hatchery was rated high quality, with some of the best salmonid habitat in the entire SF Eel River Basin;
Connick Creek – the lower section (1 mile up from confluence of the SF Eel River) is medium potential, and the upper section is low quality;
Redwood Creek (Redway) – the lower section (below Sommerville Creek) is medium potential, and the upper section (also known as Pollock Creek) is high potential refugia habitat.
Five streams were rated as high quality refugia habitat: Indian, Moody, Anderson, Low Gap, and Upper Hollow Tree creeks. Moody and Anderson creeks are located in the upper Indian Creek watershed. This basin is owned primarily by Hawthorne Timber Company, and habitat is relatively good, with excellent canopy condition, good instream temperatures, good spawning gravels, and few diversions. The Upper Hollow Tree Creek drainage and most of the land surrounding Low Gap Creek is owned by MRC, and contains excellent spawning habitat, with cool stream temperatures, good canopy coverage, and adequate flow even during the late summer months.
The majority of Western Subbasin streams were rated as high potential habitat. The climate in this subbasin is relatively cool throughout out year due to the influence of the coastal marine layer, and the topography includes many steep walled canyons and relatively narrow valleys compared to Eastern Subbasin topography. These conditions, along with the resulting cool instream temperatures in most tributaries provide good overall conditions, but road related sediment input and timber harvesting activities have resulted in diminished high quality habitat. Current forest practice rules and practices, combined with restoration (especially road decommissioning) projects may lead to some of these streams becoming high quality refugia areas in the future.
Only two creeks in the entire subbasin were rated low quality: Little Charlie Creek and Connick Creek. These creeks are heavily diverted, with corresponding high impacts to salmonid habitat and populations from low flow and poor water quality.