SAN FRANCISCO – The U.S. Army Corps of Engineers will close access to the South Boat Ramp at Lake Mendocino effective Tuesday, Aug. 18, 9 a.m., due to low water levels. The lake’s other access point, the North Boat Ramp, has previously closed due to the same reason, and Mussel Dogs are no longer conducting inspections there. The two ramp areas, though, will remain open for day use and small non-motorized boating access to the lake.
As of Aug. 15, the lake level is 726.3 feet, and there is an estimated 50,600 acre feet in the reservoir. Last year this time, the lake level was at 748.1 feet, with an estimated 86,600 acre feet in the reservoir. Water is currently being released at 165 cubic feet per second in order to maintain minimum in-stream flows for fish in the Russian River. At the current rate, the lake level is dropping about 1 foot every 5 days.
With last year being one of the wettest years over the past 25 years, this year is stacking up to be one of the driest, in fact, it’s the third driest year on record for the basin. The silver lining for Corps water managers has been Forecast Informed Reservoir Operations, or FIRO. Since 2014, Lake Mendocino has been the subject of a multi-agency FIRO research effort, with Sonoma Water, Scripps Institute of Oceanography, the Vicksburg, Miss.-based U.S. Army Engineer, Research and Development Center and several others leading the way. The aim is to develop new tools and methods to aid in water management decisions, and FIRO is being tested in real-time operations under varied conditions.
“This new approach to water management allowed for a longer boating season than would normally occur in such a dry year,” said Nick Malasavage, U.S. Army Corps of Engineers San Francisco District Operations and Readiness Division chief. “Without FIRO, we would have had to close both boat ramps prior to or on Independence Day weekend.”
The current water supply conditions for Lake Sonoma, available on Sonoma Water’s website, shows the following trends:

About FIRO
FIRO is a management strategy that uses data from watershed monitoring and modern weather and water forecasting to help water managers selectively retain or release water from reservoirs in a manner that reflects current and forecasted conditions. Since 2014, a large interagency group consisting of experts in civil engineering, hydrology, meteorology, biology, economics and climate from several federal, state and local agencies and universities has been investigating how weather forecast information can inform water management decisions such that a better balance between flood risk management, water supply and ecological concerns can be realized and safely put into practice.
COVID-19 Update for Lake Mendocino
Pomo A and Pomo B are open at this time. Visitors can access the popular Shakota Trailhead from both rec areas. The Overlook and Joe Riley are also open to walk-in and bike-in traffic only with access to several other trailheads. Oak Grove, Pomo C, Kyen Campground and Bushay Campground are closed at this time due to COVID-19 restrictions. Visitors are advised to use social distancing guidelines while visiting Lake Mendocino.
The U.S. Army Corps of Engineers owns and operates Lake Mendocino in Ukiah, Calif., and is one the nation’s leading federal providers of outdoor and water-based recreation.