Why are some Utah tanks nearly empty while others are over capacity?

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Salt Lake City – The Paiute Reservoir in southwestern Utah is now nearly empty, as the remaining water dries up in the July heat.

The tank’s demise can easily be blamed on the poor mass of snow over the past few years, which makes it impossible to recharge the tank in winter. After a few bad cycles, the Utah Department of Water Resources listed it as only 0.23% full as of Wednesday afternoon.

“Almost all of those reservoirs in the middle of the state are struggling, almost,” said Laura Haskell, drought coordinator for the Utah Department of Water Resources.

But it’s an entirely different story at Stateline Reservoir, more than 350 miles to the northeast. The reservoir in the Uinta Mountains is already venting above its listed capacity—one of two in the area still above 100% capacity even halfway through a meteorological summer.

The total capacity of the Utah reservoir system is 57% of its capacity, but why are some Utah reservoirs nearly empty while others are thriving?

There are several factors, Haskell says.

What helps and hurts Utah tanks

Utah’s reservoirs thrive on massif snow, which is the water in the snow that falls in Utah’s mountain ranges. It melts in the spring, flowing into rivers, streams and streams – much of it flowing into reservoirs built over the past century.

However, this was not always the case. Last year’s runoff was thwarted by the dry conditions of the 2020 shutdown mixed with a lower-than-average range between fall 2020 and spring 2021. Experts found that most of the runoff ended up refilling groundwater levels.

Although 2021 closed off strongly in terms of precipitation, the state’s below-average snow mass meant there wasn’t much water to flow into the reservoirs that had been depleted through drought conditions over the past two years. A massive two-decade drought has also depleted reservoir levels across the state.

But there are some differences that allow for wide ranges within Utah reservoir levels.

First, there is the size. Lake Powell, the second largest reservoir in the country, is a beast compared to most other reservoirs in the state. It’s about 48 times the size of a Piute tank. This means that Lake Powell takes much longer to empty than the Piute Reservoir, but it also takes longer to refill.

Then there is consumption. Haskell said many county areas in Utah have made a point before the irrigation season to cut back on water use this year. This allowed some reservoirs to build levels without losing water to farms or communities.

The Winter storms at the end of the season that hit northern Utah also had an effect. Depreciation cuts and last season’s storms likely listed the Stateline, Smith and Morehouse reservoirs above 100% capacity in July, and others in northeastern Utah well above the statewide average.

“I was thrown in that area,” Haskell said. “It really helped because it was snow (and) it was right at the time of the runoff. It was good timing.”

One notable example of this is the Rockport Reservoir in Summit County. tank Made headlines around the world last year When the water level fell to a point where parts of the ghost city that once existed on Earth appeared again. These low levels were the result of the tank’s inability to refill in 2021.

Rockport is now 90% full because it has had a lot more natural snowflow this spring, and it’s small enough that one year can make all the difference.

Unfortunately, spring snowstorms haven’t hit every part of the state, leaving southern and south-central Utah particularly dry. This is why most lower reservoir levels are found in these parts of the state, although lower reservoir levels can be found anywhere in the state.

According to Haskell, many reservoirs in southern and central Utah are typically bodies of water that can be refilled within one to two years. Because a lot of water was used last year, there was less than average snow mass, and some wetter spring weather escaped from the area, these reservoirs haven’t really been refilled this spring.

“They really dried out,” she said.

What does that mean for the residents who use those lockers? Haskell explains that most people have different sources of water to go to after the reservoir dries up, such as springs, streams, and aquifers. These are the kinds of sources that communities with lower reservoirs are likely to have to rely on before some reservoirs ever get water again.

Utah water supply forecast

Utah Governor Spencer Cox and Utah water experts feared that the statewide reservoir system would drop 40% last year. It’s been down below 50% for a while, but it’s never gone down. The governor said billions of gallons of water have been saved through conservation efforts to make a difference.

A year later, the state’s reservoirs are almost where they were this time last year, despite their worst starting point this year. Water levels are expected to continue declining over the next few months before stabilizing in the fall and winter.

Since there is no answer as to how long the drought will last in the state, Haskell said she hopes for similar reductions in water use over the next few months so that statewide levels do not drop too dramatically.

“We were hoping for a great winter this past year – a good mass of snow – and it was a bit disappointing,” she said. “Every drop we save now will help us in the future because we don’t know how long we’ll be in a drought.”

You can find tips on how to help reduce water consumption Online through Slow The Flow in Utah.

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