The Altar Valley Conservation Alliance is a collaborative conservation organization founded in 1995, and incorporated as a 501(c)3 not-for-profit organization. Just southwest of Tucson, Arizona, the Altar Valley comprises approximately 610,000 acres of Sonoran desert grassland, some of the most biologically rich and ecologically threatened biotic communities in the world. Private ranches work side by side with federal, state and local agencies to manage the valley, which is the largest unfragmented watershed in Pima County, outside of the Tohono O’odham Nation to the west. This collection is an archive of reports and other documents specific to Alliance activities.
Hydrogeologic Assessment of Arivaca
Pima Association of Governments
This report prepared by the Pima Association of Governments Watershed Planning Committee for the Pima County Regional Flood Control District begins with a general description of the Arivaca area before delving into details of its surface hydrology, hydrogeology, recharge rates, riparian vegetation, wells and groundwater pumping, and groundwater flow patterns.