Current Water Supply Levels

    Drought Condition Update

    The Sonoma County Water Agency's service area is currently facing drought conditions after experiencing two consecutive dry years and the driest year on record in 2013. 

    Learn more about the drought

     

    How is the drought impacting the Water Agency's reservoirs?

       

    Lake Sonoma

     
    Current Level
    149,501 AF
    61.0%
    As of 2014-09-20
      Flood Control Pool: 136,000 Acre-Feet
    Releases controlled by
    U.S. Army Corps of Engineers
     
     
    Water Supply Pool: 245,000 Acre-Feet
    Releases controlled by
    Sonoma County Water Agency
     

       

    Lake Mendocino

     
    Current Level
    30,178 AF
    27.1%
    As of 2014-09-20
      Flood Control Pool: 6,300 Acre-Feet
    Releases controlled by
    U.S. Army Corps of Engineers
     
     
    Water Supply Pool: 111,000 Acre-Feet
    Releases controlled by
    Sonoma County Water Agency
     

    Not to scale, 1 Acre-Foot (AF) = 325,851 gallons

    The Sonoma County Water Agency manages the water supply storage within Lake Mendocino and Lake Sonoma. Lake Mendocino relies on year-to-year rainfall to fill and water diverted from the Potter Valley Project, which has been reduced by more than half.  Lake Mendocino is a key drinking water source for the cities of Ukiah, Healdsburg, Cloverdale and Hopland, and also provides water to the Water Agency’s Russian River water supply system.  Water releases from Lake Mendocino support flows in the Russian River for the threatened Chinook salmon and steelhead trout during the fall and winter seasons. Lake Sonoma is about four times larger than Lake Mendocino and can provide multiple years of water supply under the current drought.  Lake Sonoma provides a majority of the Water Agency's service area with drinking water.

    Water Storage Graph

     

    *Note each day after March 1, the Water Supply Pool in Lake Mendocino is allowed to encroach into the Flood Control Pool, thus resulting in changing Water Supply and Flood Control pool numbers.

     

    About Lake Sonoma and Lake Mendocino

    The Sonoma County Water Agency (Water Agency) is the local cost-sharing partner for Lake Mendocino and Lake Sonoma, and determines the amount of water to be released when the lake levels are in the water supply pools. The US Army Corps of Engineers determines the amount of water to be released when the lake levels are above the water supply pools and in the flood control pools.

    The Russian River is a managed river system with reservoir releases controlling river flows, especially throughout most of the summer and fall.  When tributary stream flows are low, the Water Agency releases water stored in the reservoirs to supplement the natural flows in the Russian River to provide adequate flows for water supply, recreation and aquatic habitat.  A release from a reservoir can be categorized as being of ‘pass-through water’ or ‘stored water’. The term ‘project water’ is often used instead of stored water and is used to describe water that is present because of the dam and reservoir project.  Pass-through water is water flowing into the reservoir that is not stored in, but passes through, the reservoir.  Project water releases to supplement the natural flows in the Russian River and Dry Creek are necessary to meet mandatory minimum streamflow requirements that exist for both of these watercourses.

    *cfs—cubic feet per second

     

    *cfs—cubic feet per second

    *cfs—cubic feet per second

    Water Agency Drinking Water Production, Demand, Storage, and Weather Data

    Disclaimer:  The above data is based on provisional data that is subject to revision.


    Weather Forecast - When Will it Rain?

    View the National Weather Service's long-term weather forecast for Ukiah and Lake Mendocino.