Pima Association of Governments has worked with County staff for over two years on a series of riparian and water resource studies related to the SDCP and Comprehensive Land Use Plan. The three studies found within this document represent the final versions of (1) Water Quality in Pima County; (2) Water Quality of Priority Streams in Pima County; and (3) Water Quality Requirements of Native Aquatic Species in Pima County.

Provides a snapshot of past and current conditions, and represents the very best of collaborative efforts between the expert community and County staff. This study was made possible by a gift from Dr. Wendell Minckley of a database that provided information about all known surveys of native fish within Pima County, including the species, river basin, drainage, date, number of specimens collected, collector, museum catalogue number, citations, locality, and any comments made.

Arizona's fish story begins in 1904 with the publication of Morton Chambrlain's "Survey of Arizona Fishes", the first detailed study by an aquatic biologist of the area. He was able to count sixteen native species in Arizona. Today more than half are either extinct or listed as threatened or endangered, and most of the rest are considered to be imperiled. In Pima County, we count more extirpated native fish than remaining residents. The story, absent a fairly dramatic change in circumstances, will end with the extirpation or extinction of all native fish in the region. This report provides an opportunity to change the circumstances of aquatic and riparian systems in eastern Pima County.