Utah's Water Reservoir Levels Continue to Decline

Fifth year of drought reduces state's stored water supply to 36 pecent of capacity.

October 15, 2003

LeRoy W. Hooton, Jr.

Figure 1. Utah's water reservoir storage has steadily declined since 1999.

According to Randy Julander, U.S. Natural Conservation Office snow supervisor, as the new water year began on October 1, 2003, reservoir levels in Utah continued to decline this past year. The 5-year trend downward foreshadows concern over another year of drought. Statewide water storage has dropped to 36 percent from last year's 44 percent, making this the fifth consecutive year of decline (See Figure 1).

The state's reservoirs have lost nearly 3.5 million acre-feet of water over the past 5-years. The Sevier Basin is the most critical with only 2 percent of its storage remaining, followed by the Bear River with 11 percent. The Uintah Basin has the highest storage volume with 66 percent. "Utah watersheds are low and conservation will be key to next year's water supply again," said Julander. "On the bright side, this is exactly what reservoirs are for and water managers have done an outstanding job of management over the past few years."

The Sevier watershed has the lowest water supply in the state of Utah.

Sevier Basin reservoirs are nearly drained. Gunnison Reservoir for the second year is empty; Piute Reservoir is nearly empty with only 800 acre-feet of stored water remaining in the 71,800 acre-foot capacity lake; and Sevier Bridge contains only 500 acre-feet in a 236,000 acre-foot capacity reservoir. Julander notes, "The Sevier watershed is now in a state where they will be limited to actual streamflow plus whatever they can store between now and snowmelt runoff, which will be very little."

Water storage in Bear Lake is only about 11 percent of normal. Full, this large northern lake situated on the Idaho border holds 1.4 million acre-feet of water. On October 1, the volume was reduced to 152,000 acre-feet. Utah Water Users Association Executive Director Carly B. Burton said that the lake is at its lowest level since 1936. "[The] accumulated runoff for the past 4 years is only one-fourth the annual average," said Burton at a recent Association board meeting. Adding, "[The] flow below Cutler Power Plant is the lowest on record for the past 114 years."

Pineview Reservoir is 23.9 percent of capacity.

Pineview Reservoir, located east of Ogden is about 22 percent full with 23,900 acre-feet of water in storage. Water in Pineview has been regulated to accommodate dam repairs by the Bureau of Reclamation. Echo Reservoir located in Weber Canyon is only 13 percent full with 9,700 acre-feet of water in storage. Overall, the Weber drainage is 27 percent of capacity in its reservoirs.

Even the larger watershed drainages are losing water storage volumes. Flaming Gorge is only 30 percent full. Likewise Lake Powell is down to 50 percent capacity, affecting the local recreation economy and stirring evironmentalist's desire to drain the reservoir. There is growing concern all along the Colorado River system about the effects of the current drought.

Fortunately water storage in the larger populated areas of Utah and Salt Lake Counties located in the Provo drainage is 58 percent. Jordanelle Reservoir bolsters the Provo drainage with 251,000 acre-feet of water remaining in storage (78 percent). This Central Utah Project feature has maintained this volume of water during the drought period. Carry-over water in Deer Creek Reservoir allocated to the Metropolitan Water District of Salt Lake & Sandy amounts to about 25,000 acre-feet. On October 1, Little Dell located east of Salt Lake City held 14,350 acre-feet of water. These two stored water supplies enhance Salt Lake City's water supply for next year in the event the drought continues.

Echo Reservoir in Weber Canyon is only 13 percent full.

However, there is growing concern over the water storage in Utah Lake, the hub of water rights in the Provo-Utah Lake-Jordan River drainage.The lake was 6.6 feet below the old compromise level on October 1, with a storage volume of 331,000 acre-feet of water (38 percent). This is about the same level as in 1991, when a year later in mid-July 1992, water could no longer be pumped from the lake when the level dropped to 8 feet below compromise. Under the Utah Lake Management Plan, water can be called on in upstream storage facilities to satisfy Utah Lake rights next year if the volume of the lake remains low.

In southern Utah, fast growing Washington County actually improved it's water year-end storage over last year. Nevertheless, the southwest drainage storage is down to 38 percent. Water conservation and summer monsoon storms helped with added precipitation to the region.