Foss Reservoir Water Level
Foss Reservoir is at 1,637.84 ft today (Oct 19), 4.16 ft below its 1,642 ft full pool, up 0.22 ft this week.
Oklahoma · Washita River
Sponsor Foss Reservoir
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 Foss Reservoir
Foss Reservoir is a reservoir on the Washita River in Oklahoma, operated by U.S. Bureau of Reclamation. Its full summer pool sits at 1642 ft above sea level. Live water levels come from the U.S. Army Corps of Engineers (CWMS) and update hourly.
Understanding Foss Reservoir's water level
Foss Reservoir is a Bureau of Reclamation lake on the main stem of the Washita River, about fifteen miles west of Clinton. The dam was built from 1958 to 1961 as part of Reclamation's Washita Basin Project: a zoned earthfill embankment 142 feet high and 18,120 feet long, holding back runoff from roughly 1,496 square miles of drainage. Its jobs are flood control, municipal water, recreation and wildlife. The Tulsa District of the Corps of Engineers reports the level against a top of conservation pool of 1,642 feet, with an inactive pool at 1,597.2, the flood pool topping out at 1,662.2 and the dam crest at 1,697. Reclamation's allocation table uses the same figures. At normal pool the lake covers about 8,800 acres with 63 miles of shoreline, a mean depth near 23 feet and a maximum of 89. When water rises into the flood pool the Corps directs releases, and the federal operating rule caps them so the Washita stays below flood stage at Clinton and downstream at Carnegie.
The lake is the drinking water source for Clinton, Cordell, Hobart and Bessie, which draw from it through 50.8 miles of aqueduct and laterals and three pumping plants. That water is unusually hard. The Wildlife Department measured salinity of 1.06 to 1.24 parts per thousand and conductivity near 2,000 to 2,300 microsiemens, and the treatment contractor described the source as high salinity, high calcium sulfate brackish surface water. The Foss Reservoir Master Conservancy District has run a desalination plant at the dam since the early 1970s. In 2002 it ordered a $5.6 million electrodialysis reversal system that raised output from 3 to 4.5 million gallons a day for roughly 15,000 people. Because nothing is released for hydropower, the level mostly tracks rain on the upper Washita against evaporation and those municipal withdrawals. State biologists describe a typical year's swing as about two feet.
Low water at Foss is slow to recover. When the Corps' hourly record at the dam begins in September 2014, Foss was already near 1,623 feet, and it bottomed out around 1,621.9 in mid April 2015, some twenty feet low. In late May it rose about ten feet in two weeks, but it did not touch 1,642 again until May 2017. The high mark in that record came in 2019: 1,647.0 feet on 8 June 2019, five feet into flood storage, and the lake stayed above conservation pool from late May into early July. The 2022 to 2023 dry spell was milder, with a low of 1,636.05 in April 2023. In the fishery, walleye fry are stocked each year, hybrid striped bass since 1986 have produced fish over fifteen pounds, and native white bass are what biologists call the backbone of the lake. Striped bass stocked in the 1970s never became a lasting fishery.
Foss Reservoir — frequently asked
What is Foss Reservoir's full pool elevation?
The top of conservation pool is 1,642 feet, the figure the Corps of Engineers Tulsa District uses when it reports Foss as above or below normal, and the one in Reclamation's allocation table. The flood control pool extends to 1,662.2 feet, the maximum allowable water surface is 1,691 feet and the top of the dam is 1,697. Water below 1,597.2 feet is dead storage the outlets cannot reach.
What is the lowest Foss Reservoir has been?
In the Corps' continuous record at the dam, which starts in September 2014, the low is about 1,621.9 feet in mid April 2015, roughly twenty feet below conservation pool. It climbed about ten feet within two weeks in late May 2015, but it took until May 2017 to get back to 1,642.
What is the highest Foss Reservoir has been?
The highest reading in the Corps' record since 2014 is 1,647.0 feet on 8 June 2019, about five feet above conservation pool and into flood storage. Foss rose above 1,642 in late May that year and stayed above it into early July. It was well short of the top of the flood pool at 1,662.2 feet.
Why is Foss Reservoir low?
Foss has no hydropower releases, so the level falls when evaporation and withdrawals for Clinton, Cordell, Hobart and Bessie outpace runoff from the upper Washita. In a normal year the swing is only about two feet, so a drop of several feet is out of the ordinary. The Corps reported 1,637.87 feet on 28 September 2026, about four feet low and the lowest reading since spring 2023.
Which towns get their water from Foss Reservoir?
Clinton, Cordell, Hobart and Bessie, through the Foss Reservoir Master Conservancy District. Raw water is treated at a central plant at the reservoir and sent out through 50.8 miles of aqueduct and laterals with three pumping plants. Because the lake is brackish and rich in calcium sulfate, the plant uses electrodialysis reversal to desalt it, producing up to 4.5 million gallons a day after its 2002 upgrade.
Why is Foss Reservoir water so salty?
State fisheries surveys measured salinity of 1.06 to 1.24 parts per thousand and conductivity of about 1,960 to 2,320 microsiemens per centimeter. The dissolved load is largely calcium sulfate. Biologists flag that salt content as making Foss a candidate for golden algae, and zebra mussel larvae have also been found in the lake.
What fish are in Foss Reservoir?
The Oklahoma Department of Wildlife Conservation lists walleye, white bass, hybrid striped bass, crappie and channel catfish as the main sport fish. Walleye fry are stocked annually, after a stretch of saugeye stockings from 1989 to 2004. Hybrids, stocked since 1986, have produced fish over fifteen pounds. Smallmouth bass moved from Lake Lawtonka in 2002 have reproduced. Brush piles and the dam riprap supply most of the cover.
Flow released below Foss Reservoir
This gauge reads the water leaving the dam, which is the number to check for fishing, paddling and downstream conditions. Live flow is tracked on riverlvl.com.
Other lakes near Foss Reservoir
- Grand Lake O' the CherokeesOK
- Fort Gibson LakeOK
- Hugo LakeOK
- Fort Cobb ReservoirOK
- Kaw LakeOK
- Lake EufaulaOK
See current levels for all 17 Oklahoma lakes and reservoirs →
Add this gauge to your website
Run a marina, boat rental, guide service, or real-estate site on Foss Reservoir? Put this free live-level widget on your page — just copy and paste the code: