Water Report: Both Lake Sonoma and Lake Mendocino are still nearly filled to capacity
Lake Sonoma is currently at 95.2% of storage capacity and Lake Mendocino is at 83%, both excellent. Nonetheless, although they are nearly full, Sonoma Water still notes that it is important to save water. The fire season has come early to our area, among other water demands.
In this hot weather use of potable water increases; people irrigate more and need to stay hydrated. In recent years, low rainfall seriously lowered the level of water in reservoirs, both Lake Sonoma and Lake Mendocino, sources of water that are used by Sonoma Water, the supplier of water in the County of Sonoma that provides water to the Valley of Moon Water District and the City of Sonoma.
As noted on its website, Sonoma Water is the local cost-sharing partner for Lake Mendocino and Lake Sonoma, and determines the amount of water to be released from each reservoir when the lake levels are in the water supply pools. The U.S. 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.
Lake Mendocino relies on year-to-year rainfall to fill as well as water diverted from the Potter Valley Project. Lake Mendocino is a key drinking water source for the cities of Ukiah, Healdsburg, Cloverdale and Hopland, and also provides water to Sonoma Water’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. Lake Sonoma relies on rainfall to fill and supports a dynamic and fragile ecosystem in Dry Creek that includes the endangered coho salmon and threatened steelhead trout. Lake Sonoma provides a majority of Sonoma Water’s service area with its drinking water.
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, Sonoma Water 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.
To view current data provided by Sonoma Water, CLICK HERE.
