Describes a number of streams within watershed planning units and prioritizing these streams according to their existing contribution to the overall conservation of biological diversity in Pima County. Over 50 percent of the priority streams within the County are found within the Altar Valley and the Cienega Rincon area.

Regional benefits of the Rosemont Project are discussed in greater detail in the Economic Impacts Report prepared by the Seidman Institute of the Arizona State University that is part of this document. It covers Pima and Santa Cruz Counties; the major benefits accruing to Pima County.