Trinity River Watershed Management Area

Hydrologic Units: Trinity River

Description: The Trinity River is the largest tributary to the Klamath River; the basin drains a mountainous terrain of about 2,900 square miles.The U.S. Forest Service and the Bureau of Land Management manage approximately 80 percent of the Trinity WMA.About half of the remaining 20 percent is managed as industrial timberland or for cattle grazing.

The watershed is mostly rural with the population centered in the towns of Trinity Center, Weaverville, Lewiston, Hayfork, and Hyampom.In the early 1950s, two major water-development features were constructed above river-mile 112.Lewiston Dam and its reservoir and Trinity Dam and its reservoir (Trinity Lake) are collectively known as the Trinity River Diversion (TRD).The TRD diverts a majority of the upper-basin’s water at the town of Lewiston for power generation and to support the US Bureau of Reclamation’s Central Valley Project.

Salmonids: Chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch) and steelhead trout (Oncorhynchus mykiss)