Arizona Rivers Flowing After Storms
TUCSON, Ariz. For the first time in seven years, virtually every river in Arizona is doing what rivers usually do in most other places: flow with water.
Winter storms last week and this week have pumped runoff from rain or snow into stream- and riverbeds across the state. And with more Pacific storms headed into Arizona by Friday and early next week, the flows should keep coming for a while.
That's a rarity in Arizona, where most riverbeds normally are dry.
Water has disappeared in recent decades due to a combination of factors. Principal among them: increased groundwater pumping because of population growth, and drought.
Dams that capture runoff for flood control or irrigation projects have tamed even the state's mightiest river, the Colorado. And in some places, rivers like the San Pedro and the Little Colorado are barely more than a few car-lengths wide.
Reservoirs store runoff from wet years so water can be delivered during dry periods.
Despite the recent heavy precipitation, the state remains in a decade-long drought that has severely lowered the levels of giant reservoirs at Lake Mead, Lake Powell and Roosevelt Lake.
Still, runoff from the recent storms have swollen the Horseshoe Dam and Bartlett Lake reservoirs on the Verde River.
Current storage for the Salt River's system rose from 40 percent to 44 percent, and projections were that it might get as high as 50 percent, said Gregg Garfin, a program manager for climate assessment with the University of Arizona's Institute for the Study of Planet Earth.
The Theodore Roosevelt Dam, with nearly 1.1 million acre-feet of storage capacity, was 35 percent full Tuesday.
"This is the first time that it's rained significantly in 10 years on our watershed," said Jeff Lane, a spokesman for the Salt River Project, the utility that manages the reservoirs.
The storms have been so heavy and so quick, SRP has released water from the dams to ensure room for flood control in the system.
Water releases over the Granite Reef Diversion Dam were flowing in the normally dry Salt River bed through metropolitan Phoenix.
The unusual sight drew spectators to Tempe Town Lake, which is built in the Salt River channel with inflatable dams.
Carol McLuty, a 34-year-old loan officer from Phoenix, visited the lake with her daughters Wednesday to see the overflow.
"It's never been flowing like that before. ... I've been here a few times. It was actually kind of a joke that this would work. We came to see what it would look like" with the water overflowing, she said.
Szabi Szelinger, a lab assistant who was visiting the lake for the first time Wednesday, came because of the open dam.
"I wanted to see the park itself and the water going downstream because I heard they opened the dam," said Szelinger.
The flow is so quick, Town Lake was emptying and refilling itself every three hours, said Chris Baxter, the lake's marketing coordinator.
So far, the storms have produced high flows of 16,500 cubic feet per second on the Gila River near Solomon in eastern Arizona, but far less vigorous flows in southern Arizona have been recorded, averaging less than 1,000 cubic feet per second on the Santa Cruz River, said Chris Smith, a hydrologist with the U.S. Geological Survey in Tucson.
In addition, the San Pedro River was averaging less than 100 cubic feet per second as of Tuesday, he said.
"The way it normally works with these (storm) events, they saturate the soils, so if you get precipitation every couple of days, you get flow into the rivers," said Erik Pytlak, a National Weather Service meteorologist in Tucson.
Snowfall in the mountains around Flagstaff from this week's first storm might slow the runoff into the Verde River, Smith said. He warned, however, that if a storm expected Friday is warm and brings rain, runoff would increase.
"What will really benefit us is if we have a good snowpack, especially in the Salt River basin," with less runoff and more spring snowmelt to help fill Roosevelt Lake, Garfin said.
Another storm or two also probably would prolong flows in central Arizona rivers for at least a few more weeks, Smith said.
"Just because of the storms being back-to-back like this, the watersheds are saturated, and whatever falls on them is going to run off," he said.
Source: Associated Press