Originally Published: June 9, 2013 6 a.m.
A new Sierra Club report is a "call to action" to save the Upper Verde River from further streamflow reductions as a result of groundwater use.
The club's own Water Sentinels volunteers have found that the Upper Verde's baseflow, dependent upon groundwater, has declined at Perkinsville an average of 1 cubic feet per second per year during the last five years that hundreds of volunteers have been measuring its flow.
One cfs might not sound like a lot. But the average flow of the river is only about 20-25 cfs at Paulden and it drops as low as 9 cfs at Perkinsville during the summer, the report states. The Upper Verde runs about 25 miles before major streams flow into the river near Clarkdale.
"The principal threat to the Upper Verde River isn't water pollution, it's the threat posed by continuing decreases in the baseflow of the river," said Steve Pawlowski, Arizona Water Sentinels Program Coordinator for the Sierra Club. "If the trend that our Water Sentinels found continues, the Upper Verde River above Perkinsville could start drying up during the summer in as little as 10 years...that loss of a flowing Upper Verde River would be tragic."
The Sentinels have been measuring flow, collecting water samples, monitoring water quality and performing clean-up and restoration activities on the river each month for six years, led by Tom Slaback of Prescott.
"I originally volunteered to get involved in monitoring the Verde River, first water quality and then for many years water flow, because of Prescott's and Prescott Valley's plan to pump water from the Big Chino aquifer, jeopardizing the future output at the Verde Springs," Slaback said. "I felt we needed to establish a baseline which in the future would allow us to note any changes in the river flow or water quality due to groundwater pumping. If 8,000 acre-feet of groundwater is removed by pumping, the river will go dry in certain locations. We cannot allow this to happen."
The Verde River contains the longest stretch of continuous riparian habitat in the state, the Sierra Club report states. About 10 percent of Arizona's remaining Fremont cottonwood/Gooding willow habitat, the rarest forest type in North America, is found along the Verde.
The Verde Watershed supports 270 bird species and 176 reptile and mammal species, the report adds, with 80 percent of the vertebrates dependent upon the river or its riparian habitat.
The Sierra Club "Going with the Flow" report cites rising temperatures, an increasingly drier watershed, dwindling winter snowpacks and climate change as other threats to the Upper Verde.
The report quotes Jonathan Overpeck, director of the University of Arizona Institute of the Environment.
"The Southwest is going to dry out on average," Overpeck said. "We're going to have more drought, more frequent drought, and longer drought...and when it rains, it's going to rain more intensely on average, meaning more floods."
Climate change will produce winners and losers, Overpeck said, and "in the Southwest, we're going to be losers. There's no doubt."
The report also summarizes other reports about the river and climate change in the Southwest, and offers recommendations to help save the Upper Verde.
"The Water Sentinels are hopeful that the Upper Verde River will not 'go with the flow' and that it instead will flow for many generations to come," the report concludes. "We can preserve the Upper Verde River, but only if we start taking action now to save it."