Upper Mokelumne River Watershed

The Upper Mokelumne River watershed is located along the west slope of the Sierra Nevada mountain range in Central California. The topography of the watershed is hilly to mountainous, with watershed elevations ranging from 600 feet to 10,400 feet at the Sierra Nevada crest. The entire 550 square mile watershed is located within Alpine, Amador and Calaveras Counties. Like many Sierra Nevada west slope watersheds which lie in proximity to urbanizing central valley communities, the Upper Mokelumne River watershed is experiencing significant growth. The areas of highest concentrations of development lie in the western most portions of the watershed. Many of these communities originated during the gold rush era, and the infrastructure developed over the past many decades has become stressed by the ever increasing population.

UMRWA’s fundamental goals are to enhance water supply and protect water quality and the environment.  One of the primary challenges faced by UMRWA in fulfilling these goals is the Authority’s lack of jurisdiction over water and natural resource management matters. Much of the land within the watershed is managed by federal agencies and by owners of large private land holdings, with city and county governments controlling local land use decisions. Consequently UMRWA’s focus is to seek out opportunities for special watershed projects and studies that other agencies are not well positioned to undertake.

Upper Mokelumne River watershed projects and programs carried out by UMRWA include the Upper Mokelumne River Watershed Assessment and Planning Project, the associated development of the Water Assessment and Risk Management Framework (WARMF) model, and the development of a watershed Septic System Management Plan. These are presented on this website with the associated documents available by clicking on the following links: