Donner Lake is easily accessible to the metropolitan areas of Sacramento and San Francisco and is close to many recreational areas in the Sierra Nevada. The lake is used for recreation and is bordered by commercial establishments, summer vacation homes, and a large state campground. Domestic wastes around the lake have received only septic tank treatment. A sewerage system under construction and partly in use at the time of this study has been completed and now (January 1975) all domestic wastes are transported out of the basin.
In September of 1969 and 1970, a brief survey of the lake was conducted (Iwatsubo and others, 1972, p. 28). The results of that study indicated a well-established thermocline between 33 and 66 ft (10 and 20 m). A subsurface maximum in the dissolved-oxygen concentration occurred between 46 and 66 ft (14 and 20 m). In the shallow littoral zone, periphyton and patches of submerged rooted plants were visible.
In order to remain attractive for recreational use, Donner Lake will require sound management. A thorough understanding of the water quality in the lake and the quality of inflow and outflow is of paramount importance.