Originally Published: September 5, 2018 8:25 p.m.
Despite the rain we’ve received this monsoon season, the larger water issues our region faces have not been magically resolved. In this column I discuss some issues the Citizens Water Advocacy Group (CWAG) views as most important to consider.
Groundwater is the primary source of domestic, municipal, and industrial water within the Prescott Active Management Area (PrAMA). We pump far more water than is replaced; the overdraft from 1995 through 2012 in the PrAMA was about 252,000 acre-feet (approximately 82 billion gallons). This groundwater mining is unsustainable. Some wells have already gone dry, and more will follow. Legislative action to require and maintain safe yield (the long-term balance between groundwater withdrawn from the aquifer and water replenishing the aquifer) is imperative.
Requiring rainwater harvesting and landscaping with only low-water use plants in new developments would substantially reduce the 30 percent of Prescott’s yearly water use that goes to yard irrigation. In addition, rain or snowmelt captured from roofs, parking areas, and roadways could help recharge the aquifer.
The Verde River flows virtually uninterrupted nearly 140 miles from its headwater springs near Paulden to Horseshoe Reservoir and is the master drainage of the immediate Prescott area, the Big Chino Valley, and the Verde Valley. Reports by the U.S. Geological Survey conclude that “groundwater outflow from the Big Chino Valley occurs only as base flow (the groundwater component of streamflow) in the Verde River” and estimate that Big Chino Valley groundwater provides at least 80 to 85 percent of the base flow at the Paulden streamgage. This base flow, currently declining, provides more than half the annual streamflow measured at the Paulden streamgage and maintains the perennial flow of the upper 25 river miles.
There is no legal cap on groundwater pumping in the Big Chino Valley. Ever-increasing pumping there eventually will dry wells in the Paulden area and destroy vital natural habitat by reducing the uppermost 25 river miles of the Verde to an intermittent stream. Can this vital stretch of the Verde River be saved? Not under current Arizona law.
However, creation of a regulatory water management district with authority to manage groundwater in the Big Chino Valley could protect domestic wells and perennial Verde River streamflow. Such a district must be authorized by the state Legislature, and its board locally elected. Thus, the Big Chino water district would provide local control and have authority to achieve the management requirement — protecting domestic wells and perennial flow of the upper Verde River.
Legislative action at any governmental level is unlikely to occur without the advocacy of informed, committed citizens.
Please submit your questions and comments to firstname.lastname@example.org.
A panel of CWAG experts will discuss the issues above and more on Saturday, Sept. 8, from 10 a.m. to noon at the Granite Peak Unitarian Universalist Congregation building, 882 Sunset Avenue, Prescott. Details at www.cwagaz.org.
Edward W. Wolfe, Ph.D., is chair of the Citizens Water Advocacy Group Education Committee, former chair of the Verde River Basin Partnership, and a retired USGS geologist.