Eastern Subbasin Overview

The Eastern Subbasin is the largest of the three and includes all of the SF Eel River drainage east of the mainstem and to the south of the Northern Subbasin. This includes all of the eastern drainages from River-Mile (RM) 23 to the headwaters at RM 105. The Eastern Subbasin has a catchment area of 320 square miles.  This subbasin contains 435 miles of stream, 296 of which are perennial and 139 are intermittent.

Eastern subbasin streams are characterized by warmer temperatures, reduced riparian vegetation, and higher stream gradients compared to other subbasins; this subbasin is not located in the coastal fog belt, and vegetation in much of the basin consists of grassland/prairie, with patches of mixed conifer and hardwood forest in the western areas.  Major tributaries in this subbasin include the East Branch SF Eel River, Rattlesnake Creek, and Tenmile Creek near Laytonville.  Land use is primarily grazing, timber, and residential development.  Primary issues in Eastern Subbasin streams are: reduced flow due to diversion (especially during late summer and early fall months) and warm water temperatures, which have favored the establishment of invasive species such as Sacramento Pikeminnow.  Warmer temperatures and reduced flow also provide ideal conditions for blue green algae blooms, which have become a hazard for dogs and humans.

Salmonid populations in Eastern subbasin streams are reduced in both distribution and abundance compared to other SF Eel River streams, and there are few streams with high suitability for salmonids in this Subbasin.
Attributes of the SF Eel River Eastern Subbasin
Area (square miles) 320
Privately Owned (square miles) 266
Publicly Owned (square miles) 53
Predominant Land Use Timber harvest and rural residential
Predominant Vegetation Mixed conifer and hardwood forest
Mainstem Miles 82.1 (RM 22.9-105)
Tributary Miles 360
Total Stream Miles 442
Low Elevation (feet) 65
High Elevation (feet) 4491
Dean Creek, under Hwy 101 bridge, at low flow (courtesy of CDFW)

East Branch SF Eel River, at low flow with warm water and algae. (courtesy of CDFW)

Rattlesnake Creek, Eastern Subbasin (courtesy of CDFW)