Lake Sonoma Water Level
Lake Sonoma is at 443.70 ft today (Oct 31), 7.40 ft below its 451.1 ft full pool, down 0.63 ft this week.
California · Dry Creek
Get a text when Lake Sonoma crosses a level you pick →
Sponsor Lake Sonoma
Put your marina, real-estate, or local business in front of everyone checking this lake's level. One exclusive sponsor per lake.
Renews automatically each month or year until you cancel. Cancel anytime online. Terms · Manage or cancel · Questions?
Water level history
About Lake Sonoma
Lake Sonoma is a reservoir on the Dry Creek in California, operated by U.S. Army Corps of Engineers. Its full summer pool sits at 451.1 ft above sea level. Live water levels come from the U.S. Army Corps of Engineers (CWMS) and update hourly.
Understanding Lake Sonoma's water level
Lake Sonoma is the largest reservoir in the Russian River water system and the main savings account behind the tap water of more than 600,000 people in Sonoma and northern Marin counties. Warm Springs Dam, a rolled earth embankment 319 feet high and about 3,000 feet long, closes off Dry Creek roughly fourteen miles northwest of Healdsburg. Its total capacity is 381,000 acre-feet. The bottom 245,000 acre-feet, the conservation pool between about 292 and 451 feet, belongs to water supply, and Sonoma Water draws on that storage. Water released down Dry Creek reaches the Russian River and is pulled back out of the riverbed gravels by collector wells near Wohler Bridge and Mirabel Park, then pumped through an aqueduct system with more than 88 miles of pipe. In a typical year the region takes around 50,000 acre-feet out of the lake, closer to 70,000 in a dry one.
Above the water supply pool sits 136,000 acre-feet of space the Army Corps of Engineers San Francisco District keeps empty year round for floods. The spillway crest is at 495 feet. When storms push the lake into that upper zone, the Corps meters water out with two targets in mind: no more than 7,000 cubic feet per second in Dry Creek below the dam, and no more than 35,000 cfs on the Russian River at Guerneville. In March 2023 storms lifted it to 466.72 feet and 288,766 acre-feet, into the flood pool for the first time since 2019, and the Corps ramped releases up toward 4,000 cfs to make room. Since the 2023 water year the Corps has also let Sonoma Water hold extra water under Forecast Informed Reservoir Operations, a minor deviation that raises the storage target to 264,000 acre-feet when forecasts show no big storm coming.
The dam took a long time to build. The Corps signed the contract in 1964 and started work in 1967, a federal lawsuit on environmental grounds stopped construction in 1974, and work resumed in 1978. Sonoma County voters approved a bond in 1974 to cover the local 35 percent share, then rejected a 1979 measure to pull out by close to three to one. Sonoma Water says the lake began storing water in 1984. Just below the dam, the Warm Springs Hatchery, also called the Don Clausen Fish Hatchery, is run by the California Department of Fish and Wildlife and raises coho salmon and steelhead for the Russian River basin, trapping 3,000 to 5,000 returning steelhead a year. The three dry years ending in 2022 drained the lake to the lowest level in its history, about 102,500 acre-feet in November 2022, or roughly 42 percent of the water supply pool.
Lake Sonoma — frequently asked
What is Lake Sonoma's full pool elevation?
The top of the water supply, or conservation, pool is about 451 feet, which lakelvl.com lists as 451.1 feet. At that level the lake holds 245,000 acre-feet. Anything above it is flood storage: another 136,000 acre-feet that the Army Corps keeps available all year, up to the spillway crest at 495 feet. Total capacity is 381,000 acre-feet, so a reading in the 460s means the lake is holding floodwater that will be released.
What was Lake Sonoma's lowest level?
The record low came in late 2022, after three straight dry years. In early November 2022 the lake held about 102,500 acre-feet, less than 42 percent of its 245,000 acre-foot water supply pool, down from 152,474 acre-feet that January. It had nearly reached that point in October 2021, at 105,509 acre-feet, before an atmospheric river refilled some of it. Sonoma Water said at the time there was no imminent risk of the lake going dry.
Why is Lake Sonoma sometimes above full pool?
When winter storms push the lake past about 451 feet, the extra water sits in the flood control pool and the Corps releases it on its own schedule. Releases are held to what Dry Creek can carry, 7,000 cubic feet per second, and timed so the Russian River at Guerneville stays under 35,000 cfs. In March 2023 the lake reached 466.72 feet and the Corps made its first high flow release in nearly four years, ramping toward 4,000 cfs.
How long did Lake Sonoma take to refill after the drought?
One wet winter. After bottoming out in late 2022, the water supply pool was full again by the end of February 2023, at 244,833 acre-feet, the first time since 2019. The Press Democrat reported that a full pool can cover domestic needs and required stream flows for three to five years. By mid March 2023 the lake had risen well into the flood pool.
What is FIRO at Lake Sonoma?
Forecast Informed Reservoir Operations lets the Corps keep more water in the lake when weather forecasts show no large storm coming, instead of releasing it on a fixed calendar. It was proven first at Lake Mendocino, where the Corps began interim operations in water year 2019. At Lake Sonoma a minor deviation raises the water supply storage target from 245,000 to 264,000 acre-feet, which saved more than 19,000 acre-feet in water year 2023.
What emergency actions did the 2021 drought trigger?
Governor Newsom declared a drought emergency in Sonoma and Mendocino counties on April 21, 2021, and Sonoma County supervisors followed on April 27. In May, county officials approved a 20 percent cut in pumping from the Russian River, and the 2022 state order also required a 20 percent diversion reduction. Healdsburg adopted mandatory 40 percent conservation in June 2021, and Santa Rosa a mandatory 20 percent cut.
Where is the fish hatchery at Lake Sonoma?
The Warm Springs Hatchery, also known as the Don Clausen Fish Hatchery, sits just below Warm Springs Dam at 3246 Skaggs Springs Road near Geyserville. The California Department of Fish and Wildlife raises coho salmon and steelhead there for the Russian River drainage and traps 3,000 to 5,000 steelhead each year. The Army Corps runs the visitor center, which is open 10 a.m. to 4 p.m. daily.
Other lakes near Lake Sonoma
- Stampede ReservoirCA
- Lake ShastaCA
- Success LakeCA
- Prosser Creek ReservoirCA
- Lake TahoeCA/NV
- Pine Flat LakeCA
See current levels for all 29 California lakes and reservoirs →
Add this gauge to your website
Run a marina, boat rental, guide service, or real-estate site on Lake Sonoma? Put this free live-level widget on your page — just copy and paste the code: