It’s been a dry year, but last year was worse.
So far this year the Moab-area has received three inches of precipitation, according to Weather Underground. Last year, during the same time period, less than one and half inches of precipitation fell.
The combination of the two dry years, very dry soils absorbing the precipitation and a slow snow melt has left Ken’s Lake at 30 percent of normal.
“Right now it is as full as it will get,” said Mark Sovine, director of Grand Water and Sewer Service Agency (GWSSA). “We’re at the point that we will start drawing down.”
The only potential increase of water for the lake would come from summer storms or monsoons.
“If we have a torrential rain storm, the conditions can change,” Sovine said.
The storm that dropped rain during the first week of May was a good example.
“People used less water and the lake rose,” he said.
Due to the low level in Ken’s Lake, 165 irrigation users in Spanish Valley have been allotted less water this year. The allotments were cut to 50 percent in April. By the GWSSA’s meeting on May 22, the allotments were dropped to 40 percent.
Due to the continued low water conditions, GWSSA began a discussion with the Bureau of Land Management (BLM) about diverting more water from Mill Creek to Ken’s Lake. At this time, GWSSA is only able to divert water from Mill Creek through the Sheley Tunnel when stream flow is above three cubic feet per second (cfs).
“We are aggressively pursuing that option,” Sovine said.
Bill Love, a Spanish Valley resident, has expressed concern regarding the diverting additional water from Mill Creek.
“GWSSA’s proposal to reduce the flow in the south fork of Mill Creek is not only a risk to the creek bed, but is a transfer of culinary water to irrigation water for about 100 Ken’s Lake users,” he said.
He cited a United State Geological Survey (USGS) study completed in 1990 that stated that the Glen Canyon aquifer, which is the source of culinary water for Moab, is recharged by 650-acre feet of water a year.
“This is enough water for 1000 homes in the city,” Love said.
As the water travels over 8.6 miles of sandstone stream bed in Mill Creek, water seeps down into the Glen Canyon aquifer, recharging it.
However, the USGS figure of 650-acre feet of water that was measured in the late 1980s for the 1990 report has been contested.
Sovine, along with Moab city engineer Rebecca Andrus and two USGS hydrologists, took their own measurement on Wednesday, May 29. According to their calculations, the recharge was 270-acre feet.
Andrus wasn’t sure why there was such a marked difference.
“Maybe when the ground is more saturated in the spring, it doesn’t recharge as much. Maybe when the aquifer has been drawn down all summer from pumping of the wells, it may recharge more. But these are all assumptions,” Andrus said. “We have two measurements in time. One in May and one in October and both are twenty years apart.”
Andrus said that taking several measurements around the year would help them have a better understanding of how the aquifer recharges, which in turn would help them in making decisions.
“It is my understanding that GWSSA is looking for alternatives and that they are putting ideas out there to be analyzed for benefits/consequences,” Andrus said. “It is really a data gathering stage, and the city supports efforts to better understand the aquifer. This is only one of a myriad of solutions that are being considered to try to shore up water supply.”
She said that if measurements show that the aquifer recharges more in the fall when it is low and the ground is dry than in the winter when the ground is wet and the aquifer is high, then it may be beneficial to increase the water diverted into Ken’s Lake in the wintertime to fill it earlier in the year.
“If during the winter the ground is saturated and it’s not drawing, then we may be able to keep more water in the stream in the summer when it does recharge,” Andrus said. “Maybe we can drop the waterflow to 1 or 2 cfs and test it in the winter.”
GWSSA also pumps water from the Valley Fill aquifer for irrigation customers.
Mark Sovine said that while the Valley Fill aquifer was drawn down last summer when irrigation water was limited, it did recharge.
“All of our monitoring is showing that the water tables are holding their own,” Sovine said. “It showed good recovery in the winter.”
Most of the irrigation customers in Spanish Valley who have their own wells would also be drawing from the Valley Fill aquifer; the exception would be those on the east bench near the golf course, which would be drawing from the Glen Canyon aquifer.
However, Sovine doesn’t want irrigation to be dependent upon using the wells as a long-term solution. “This is part of the whole request with the BLM. While we haven’t seen any draw down, we don’t know how long we can sustain that,” Sovine said.
The Glen Canyon aquifer, which supplies all the culinary water for Moab, has fluctuated over the years.
Before Ken’s Lake was built in the early 1980s, the city measured between 100 and 200 gallons per minute from Spring 3. After Ken’s Lake was put in place, it spiked to 500 and 600 gallons per minute in the mid to late 1980s.
“The concept is that Ken’s Lake is leaking and filling the aquifer, which is true to a degree, but also, because we’re using Ken’s Lake we’re not drawing off the aquifer,” Sovine said. “Regardless of what the reason is, it is making a difference.”
Over the 1990s it dropped to highs of 500 gallons per minute. Over the last decade the highs have averaged around 400 gallons per minute.
As more visitors come to the Moab, more water is being used.
“Water usage during the summer every year causes the city to turn on our pumps to provide 40 percent of the annual supply,” Andrus said.
Moab residents use 32 million gallons a year. Commercial use is at 55 million gallons a year. Moab hotels alone, for indoor use only, use 8.9 million gallons a year.
During the winter when water usage is low, the springs provide more water than is needed by city residents. The overflow is dumped by the city into Mill Creek to flow to the Colorado River.
“Living in a desert as we do, there are always concerns about water. Sadly, most people only worry about it during drought times when stark reality hits, and it is too late to do much about it,” Andrus said. “Since we do not know the sustainable yield of the aquifer, we should be constantly vigilant in protecting and preserving both the quantity and quality of the water in the Glen Canyon Aquifer, which has been designated as the sole source for the City of Moab.”
Living in a desert as we do, there are always concerns about water. Sadly, most people only worry about it during drought times when stark reality hits, and it is too late to do much about it.”