Welcome to theClear Lake Water Resources Hub

Live water quality data from the Oaks and Lower arms dataloggers and current maps of fish die off locations.

A health hazard assessment conducted by the California Department of Food and Agriculture examining Native American exposure to the herbicide fluridone through consumption of tules (aquatic vegetation) at Clear Lake, California. The study was prompted by tribal concerns about fluridone applications under the CDFA Hydrilla Eradication Program. Environmental sampling of lakeshore vegetation, water, and sediment was conducted at four locations before and after seasonal herbicide applications in 2005. Subchronic and chronic exposure scenarios were evaluated using ingestion rates developed in collaboration with tribal members. Hazard quotients calculated for worst-case exposure scenarios indicated little to no risk of adverse health effects from fluridone ingestion at current application levels.

A water resource climate adaptation plan prepared by FlowWest for the Big Valley Band of Pomo Indians, focused on the recovery of the Clear Lake hitch (Lavinia exilicauda chi) in Adobe Creek, a tributary to Clear Lake, California. The plan documents the cultural and biological significance of the hitch to Pomo people, who have inhabited the Clear Lake area for over 11,800 years, and outlines the historical and ongoing threats to the species including dam construction, channel modification, gravel mining, reduced instream flows, and climate change impacts such as increased drought and temperature variability. The hitch is listed as threatened under the California Endangered Species Act (2014) and is assessed at high risk of extinction in the wild.

A habitat suitability assessment prepared for the Big Valley Band of Pomo Indians examining streamflow and habitat requirements for the Clear Lake hitch (Lavinia exilicauda chi) in Adobe Creek, a tributary to Clear Lake, California. The study combines new topographic and hydrodynamic modeling data with Traditional Ecological Knowledge (TEK) from tribal members to identify minimum flows needed for chi migration and spawning. It documents the critically declining chi population — with only six individuals observed in 2022 USGS gill net surveys — and aims to support water resource management in the Big Valley Subbasin to protect the species, which is listed as threatened under the California Endangered Species Act (CESA).

A report documenting multiple fish rescue operations conducted in May and June 2014 by the California Department of Fish and Wildlife (CDFW), in collaboration with volunteers from local tribes including Robinson Rancheria and Big Valley Rancheria, on Adobe and Cooper Creeks in Lake County, California. The rescues aimed to capture and relocate Clear Lake hitch (Lavinia exilicauda chi), a species threatened under the California Endangered Species Act (CESA), from isolated and rapidly drying pools. The report details the species collected, rescue methods, relocation sites, and observed mortalities.