Ending Water Year Reservoir Levels

Lower reservoir levels reflect the effects of current drought conditions.

October 3, 2002

Jordanelle Reservoir stores water supply for the Wasatch Front. This Central Utah Project reservoir is designed to provide water supplies during multi-year droughts and meet population growth along the Wasatch Front.

As the 2001-2002 Water Year ends, a survey of the state’s water reservoirs shows a decline in stored water over last year.  According to data compiled by Randy Julander, U.S. Natural Resource Conservation Office snow survey supervisor, reservoir storage statewide is down to 43 percent of capacity.  Last year the state average was 60 percent. The reduction is a result of last winter's poor snowpack and a continuation of four consecutive years of less than normal precipitation, resulting in varying degrees of drought conditions throughout the state.

Statewide Storage    Volumes      Area Percentage Provo River 62% Duchesne 70% SE Utah 30% Sevier Basin 12% S Utah 27% Weber 41% Bear River 24% State Average 43%

The decline in reservoir levels varies throughout the state. In the southwestern part of the state, lack of precipitation has depleted the storage in Quail Creek Reservoir, located north of St. George from about 65 percent last year to 36 percent this year. The reservoir when filled contains 40,000 acre-feet of drinking water supply for fast growing Washington County. Approximately 15,000 acre-feet of water remain in the reservoir for use next year. Gunlock Reservoir located west of St. George is down to 25 percent of its capacity. Water from this reservoir is not used for municipal purposes.

One hundred miles further north, the Minersville Reservoir is down to 6 percent of its capacity.  Located 16 miles west of Beaver, the reservoir level reflects the drought conditions in south-central Utah. Overall reservoir storage in this region of the state is extremely low.  Sevier Bridge is 15 percent, Otter Creek 11 percent and Piute 4 percent full.

In the central-northern part of the state water storage is better than in the southern part of the state. Strawberry Reservoir, located approximately 50 miles east of Salt Lake City on SH 40, currently holds 73 percent of its water volume, down from 86 percent last water year. This reservoir, part of the Central Utah Project, stores water from the vast collection system situated along the Uinta Mountain range that diverts a portion of the state’s Colorado River allocation.

Jordanelle Reservoir located northwest of Heber City, is another feature of the Central Utah Project.  At the end of the water year this reservoir contained approximately 240,000 acre-feet of water, which is 76 percent of its capacity. A major source of drinking water for the Wasatch Front, this project ensures an adequate water supply for the large population residing in Utah and Salt Lake counties.

Top: Quail Creek Dam located north of St. George, Utah. Low water level and a cofferdam allow maintenance of the dam. Bottom: Minersville Reservoir located 16-miles west of Beaver, Utah is down to 6 percent of its capacity.

Downstream from Jordanelle is Deer Creek Reservoir located in Provo Canyon between Heber City and Provo/Orem. This reservoir is a major drinking water supply for Salt Lake City. Waters stored in Deer Creek Reservoir are authorized under water rights owned by the Provo River Water Users Association for two transmountain and Provo River diversions. The watersheds that feed snowmelt into the Weber, Duchesne and Provo rivers have been especially impacted by the drought conditions. Lower inflows into the reservoir and high demand due to abnormally hot and dry weather during the summer months have reduced the volume of water in storage in Deer Creek to below 40 percent. Of the 60,000 acre-feet of water in storage, Provo River Project water is about 29,000 acre-feet. This water is owned by individual shareholders in the form of holdover water that can be used next year.  This is the second lowest amount recorded since the project was completed in 1941.  Water allocation during 2001-02 was only 55 percent.

It is estimated that the Metropolitan Water District of Salt Lake & Sandy will be able to holdover about 10,000 acre-feet of water for next year. According to general manager G. Keith Denos, rains in September reduced water demand and helped stop the water levels from dropping even further in Deer Creek. “We were projecting that the total volume in the reservoir would reach even lower values, but the downward trend stopped and then flatted out during September,” says Denos.

The water level in Little Dell Reservoir located 5-miles east of Salt Lake City has actually increased 49 percent from 9,224 acre-feet last year to 13,698 this year. Salt Lake City Department of Public Utilities credits water management and conservation for this increase. “In the event there is another year of drought and the need to protect Salt Lake City’s water customers from serious shortages, we have saved as much water as possible in Little Dell,” says public utilities deputy director Jeffery Niermeyer.  

Weber Basin reservoir storage is 41 percent of capacity. Reservoir storage varies from a low of 22 percent in Pineview to a high of 75 percent in Smith & Moorehouse Reservoir. Pineview was purposely lowered by the Bureau of Reclamation this year to make repairs to the dam

In the far northern part of the state is Bear River Reservoir. Water volumes have decreased from 40 percent to 25 percent this past year. The overall average storage in the Bear River Basin is about 23 percent.

Water management and demand conservation helped increase the volume of water in Little Dell Reservoir located east of Salt Lake City.

Lake Powell stores water from the Upper Colorado River Basin located in Utah, Wyoming and Colorado. The current storage is approximately 14.9 million acre-feet (61 percent of volume) with a level 73 feet from full pool.  The dramatic decline in water volume is attributed to three years of less than normal snowmelt flows.  This year the unregulated flow into the reservoir amounted to only 24 percent of normal. This demonstrates the magnitude of the drought affecting upper Colorado River Basin states. Drought conditions in Colorado have been described as a 100 year event.

State water managers are hoping for a return of more normal precipitation and snowpack this coming winter. Regardless of favorable weather prognostications and hopeful wishes, water levels in Utah’s reservoirs are lower than normal as a new water year begins.