Builds upon the "Biological Stress Assessment" through the identification of threats and stressors to watercourses within Pima County. It provides background on technical and water policy matters, describes potential and existing impacts to watercourses within Pima County, suggests options for reducing stressors, and outlines a number of issues for discussion withing each watershed planning unit.

If one species had to be chosen to preserve and restore, perhaps it should be cottonwood. Cottonwood-willow forests, where they exist and are healthy, indicated the presence of a viable riparian area, which is in turn the key to conserving great proportions of our native species. A reflection of the dire status of our riparian systems is that the Sonoran cottonwood-willow and Sonoran mesquite-cottonwood forests.