The main pond at Agua Caliente Park is looking less like a mud flat and more like an inviting oasis once again.
An estimated 40 percent of the 3.5-acre pond northeast of Tucson had dried up last month as drought plagued the area - but much of the once-dry surface is now covered with at least a few inches of water.
Credit recent relatively cool weather, monsoon rainfall and continued pumping of well water into the pond, said Kerry Baldwin, Natural Resources Division manager for Pima County.
The county manages the park, which is highly valued as a recreation site and wildlife habitat.
"We got a little bit of kick from a number of factors" that have reversed the drying trend - at least for now, Baldwin said. "We're pumping about 55,000 gallons a day of well water into the pond. Temperatures are down (reducing evaporation), and the rainfall we've been getting can't hurt a bit."
Still, Baldwin noted, water levels have risen just a few inches - enough to obscure some of the mud flats but not enough to refill the pond completely.
A key cause of the recent dry-up: "We're getting no flow from the spring" that once kept the pond full, Baldwin said.
"The spring has been off and on for the last three years," he said. "More often there is no flow than water flowing, especially in the summer months."
To offset the shortage, the county has been pumping 55,000 gallons of well water daily into the pond. That's the maximum that can be drawn from the well in accordance with a permit from the Arizona Department of Water Resources.
Baldwin said county officials are looking into long-term solutions "to get us back to a sustainable water system." Among plans under consideration are renovating the pond, reducing its size and sealing the bottom to limit water loss.
"We want to maintain the pond for its biological and ecological value - and also because it's an icon for that park," Baldwin said. "People want to see open surface water - not a big mud flat."
On StarNet: The main pond rebounds, azstarnet.com/video
about the park
• Roy P. Drachman-Agua Caliente Regional Park is at 12325 E. Roger Road.
• Its name means "hot water" in Spanish - a reference to the hot springs that once flowed abundantly in the area.
Contact reporter Doug Kreutz at email@example.com or at 573-4192. On Twitter: @DouglasKreutz