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 ecologic al choregraphy. The upper San Pedro River basin of southern Arizona (USA) a nd northern Sonora (Mexico) is used as an example. This watershed is curren tly facing significant growth pressures. Rapid urbanization, cattle ranchin g, and irrigated agricultural pumping in the drainage basin are having nega tive environmental consequences, including water quality and supply problem s, increased soil erosion, threats to wildlife habitats, and degradation of scenic resources. Copper mining, just outside the watershed, potentially i mpacts groundwater and the San Pedro riparian system. The protection of env ironmentally sensitive areas would help to maintain the biological integrit y of the region. This paper focuses on the design of a framework for the id entification of environmentally sensitive areas in the watershed and an ana lysis of existing government plans to protect such areas. The proposed fram ework can coordinate local, state, and federal efforts to achieve their pro tection objectives. (C) 2000 Elsevier Science B.V. All rights reserved.