Laurie Wirt Presentation

Semiarid Big and Little Chino valleys are undergoing rapid growth, their populations solely dependent solely on ground water. Although the basins contain considerable amounts of ground water, from a historical perspective, groundwater overpumping in excess of safe yield inevitably leads to reduction or loss of perennial streams. The source of base flow to the Upper Verde River is the discharge from two basin-fill aquifers---the Big Chino basin-fill aquifer and the Little Chino basin-fill aquifer. Maintaining this discharge is critical toward maintaining base flow in the upper Verde River which is in turn critical for to maintain base flow for grandfathered downstream surface-water users in Verde Valley and Phoenix as well as for the maintenance of fish and game in some of the best remaining wildlife habitat in the State.
The goal of my talk today is to summarize some of the results of a recent USGS study1 on the geologic framework of the Verde River headwaters in the hope that a better understanding of the hydrologic system will help to clarify the science and lead to more informed decision making by stakeholders and the voting public regarding water resources. View Document.