The San Pedro Riparian National Conservation Area was designated on November 18, 1988, by Congress to “conserve, protect, and enhance the riparian area and the aquatic, wildlife, archaeological, paleontological, scientific, cultural, educational, and recreational resources of the conservation area.” Congress also expressly reserved a quantity of water sufficient to fulfill the purposes of the San Pedro Riparian NCA. The NCA lands (about 56,0000 acres) are located in southeastern Arizona, stretching south of Benson to the U.S.-Mexico border and containing 40 miles of the upper San Pedro River. The NCA is highly significant not only for the San Pedro river but the important riparian and grassland habitats. These lands are home to more than 80 species of mammals, two native species of fish, more than 40 species of amphibians and reptiles, and 100 species of resident birds.
Federal officials assert that since BLM holds a federal reserved water right, sufficient to fulfill the purposes, BLM enjoys greater protection from groundwater pumping than holders of state law water rights. That means that the Arizona Department of Water Resources must consider these rights when considering requests like new development to pump water. ADWR must consider all information necessary to determine that an adequate supply of water is legally available for an applicant but also whether additional pumping will impact the federal reserve water right for SPRNCA.
In the recent Court ruling, the Court did not find it necessary to consider the impacts to the NCA from the proposed housing development but ADWR must consider the reserved water rights.
Photo courtesy U.S. Bureau of Land Management.