Heavy use and light winter deplete water
Ryan Summerlin October 2, 2012
When it rains, it pours. And when it doesn’t rain, the water supply dwindles.
The large reservoirs within the Weber Basin Water Conservancy District are already half gone due to lack of moisture and heavy water use this year.
The reservoirs are designed for a two-year water supply, and the average depletion at this time of year is about 65 percent.
"So there is quite a bit of a difference," District General Manager Tage Flint said. "We get nervous when we start operating on that second-year supply without the hope of a lot more coming in. So this winter will be very important."
To conserve the remaining water supply, the district has called for voluntary water restrictions across all five counties the district serves, including Summit, Morgan, Davis, Weber and part of Box Elder counties.
If this coming winter is dry, Flint said they will be concerned and will likely call for mandatory irrigation restrictions.
"We would definitely not fill our reservoirs all the way to the top next spring, and then we would start with a condition that’s even worse than this year," Flint said. "And we’d be looking at less reservoir storage at the end of next year. So it kind of compounds."
There are two factors that play into the low water supply this year.
The first is that even though the reservoirs were full at the beginning of the year, little precipitation throughout last winter led to very low runoff in the spring.
"In a normal year, that runoff would be used clear through June," Flint said. "But this year that runoff wasn’t there, so we started drawing from that storage much earlier to make up the difference."
Additionally, the summer has been hot and dry, causing water usage to rise as the plant materials demand a lot more water than usual.
"It’s kind of two strikes in one summer," Flint said.
Recently, district officials have been asking the public to pay attention to their automatic sprinkler clocks and turn them down considerably from where they were in July.
"What we see happening a lot, is the normal homeowner will start watering their lawns in the springtime and they will ramp the times upward as it gets hotter," Flint said. "But they aren’t nearly as diligent in ramping them back down as it gets cooler. And so those automatic clocks are still putting on a lot more water now then they need."
In September, lawns require about 50 percent of the water they need in July, and only once-a-week watering. The district is asking irrigation systems to be shut off entirely by October.
"The landscape does not need it, nor will it suffer long-term by not being watered beginning in October," Flint said. "We’re not asking anyone to sacrifice their landscape. We’re just asking them to be very diligent in cutting the water use down."
Flint also recommends more efficient sprinkler systems, using drip systems, paying attention to zones so plants with similar water needs are planted together and buying plants that require less water.
"In Utah, people traditionally have plants of European descent that need a ton of water," Flint said. "We have hundreds and hundreds of plants in our demonstration garden at our headquarters now that are lush and green and often prettier than the ones that are around, that are using much less water."
The voluntary water restrictions have proven effective, as the district has seen a 10 to 15 percent reduction in water use since the restrictions went into effect.
But in the long term, the district hopes to achieve a goal of a 25 percent per capita reduction by 2030.
"Because so much of our water is used outside among gardens, that’s where the savings can really take effect," Flint said. "We’re not promoting Tucson-type landscapes. We’re not promoting cactus and gravel. We still maintain there is an opportunity to maintain a green, lush landscape and use at least 25 percent less water."