Key issues, institutions, and strategies for managing transboundary water resources in the Arizona-Mexico border region

The region transected by the international border separating Mexico and the United States is one of the world’s most distinctive transboundary zones. Running more than 3,100 kilometers from the Pacific to the Atlantic Oceans, it is the world’s tenth longest frontier (see Fig. 1 [map]). But more significantly, the U.S.-Mexico border separates two countries with widely disparate wealth. The ratio of gross domestic product (GDP) per capita of nearly five to one, though it has been diminishing over the past decade, remains among the world’s 20 or so highest, ranking alongside Germany-Poland, Chile-Bolivia, and Russia-North Korea. Of relevance for our present program, Israel’s borders with its neighbors exhibit similar, though even wider gulfs in wealth. Israel’s ratios with Jordan, Syria, Egypt, and Palestine are 8.1, 10.5, 13.8, and 20.1 - this last, the world’s highest.