SALT LAKE CITY — With the new water year off to an official start Saturday, most of Utah's reservoirs remain chock full — a condition that has water managers mostly pleased but a bit worried.
Reservoirs such as Strawberry, Deer Creek and Pineview in Weber County are at 90 percent of capacity or better, and in cases like Starvation, which is 80 percent full, or Wanship, hovering at 49 percent of capacity, those levels have been drawn down deliberately.
"At Wanship, we have been dropping reservoir storage to some levels that are as low as we have historically ever been," said Weber Basin Water Conservancy District's Chris Hogge.
At a water supply briefing he gave to board members Friday, Hogge said the district's reservoirs have a combined 441,750 acre feet of water — up 82,790 acre feet of water from what the district had last year at this time.
"The high holdover in these reservoirs presents another issue of how we manage these levels," Hogge said.
If the district releases too much water to make room for additional storage, that decision will bite them next summer if it is a winter of little precipitation.
In contrast, if the snow starts piling up in the mountains deep and early on, the district has to be prepared to drop reservoir levels beginning as soon as late December or January.
Right now, according to the district's general manager Tage Flint, there are no plans to make any drastic changes through the fall months.
Farther south, the Central Utah Water Conservancy District deliberately dropped Starvation to 80 percent so it can be brought back up to 85 percent over the next several weeks.
Starvation will take on extra water, rather than allowing it to pass through, to allow downstream property owners to complete flood repairs along the Strawberry River.
Tom Bruton, the Uintah operations and maintenance manager for the district, said that generally, reservoir levels will be dropped to make way for an average snowpack.
"This last year was really interesting," Bruton said. "It was a set of scenarios we had not seen before. In a way it was challenging, the word would be 'almost fun.'"
Bruton recalled being out in the middle of the night with a bunch of other folks to check the level of the Duchesne River.
"We had a flashlight and were looking at that river. I just wish we had hot dogs and a bonfire. That would have made it."
From an operational standpoint, Bruton said the beyond ample snowpack did little to change how the district made its decisions — even if it did keep people up all night.
"We have a little bit more room to be more aggressive or less aggressive depending on the forecast."
That room comes with the extra size and thus extra storage capacity of big water bodies like Strawberry, Starvation and Jordanelle.
Bruton said the reservoirs were constructed with flood control and multiyear carry-over capacity for water storage — in contrast to Weber Basin's system, which was not designed with as much flood control stop gaps in mind.
Jordanelle was built with the ability to have three-year supply of water carry over, while Strawberry was built in anticipation of a 10-year "considerably dry" period, according to Bruton.
That type of capacity gives the district the flexibility to drop levels to a range where it can comfortably make room for more water or slow down its releases in light of a dry year, he said.
"We have these sweet spots where we can hold our reservoirs so we have the most flexibility operationally. It allows us to be prepared for a very wet year or very dry year."
Flint, who concedes he has less wiggle room than his colleague to the south, admits the hard part is not having that crystal ball to tell him what the months will bring or a magic wand to produce his ideal winter.
"We are almost always good with normal, but we never get it," he said. "Average would be good."
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