A watershed at a watershed: the potential for environmentally sensitive area protection in the upper San Pedro Drainage Basin (Mexico and USA)

The watershed is advocated as an appropriate unit for ecological planning. Watersheds, or river drainage basins, can be understood through an ecological chorography. The upper San Pedro River basin of southern Arizona (USA) and northern Sonora (Mexico) is used as an example. This watershed is currently facing significant growth pressures. Rapid urbanization, cattle ranching, and irrigated agricultural pumping in the drainage basin are having negative environmental consequences, including water quality and supply problems, increased soil erosion, threats to wildlife habitats, and degradation of scenic resources. Copper mining, just outside the watershed, potentially impacts groundwater and the San Pedro riparian system. The protection of environmentally sensitive areas would help to maintain the biological integrity of the region. This paper focuses on the design of a framework for the identification of environmentally sensitive areas in the watershed and an analysis of existing government plans to protect such areas. The proposed framework can coordinate local, state, and federal efforts to achieve their protection objectives.