The Upper San Pedro partnership

Endangered Species Bulletin, Jan-Feb, 2004 by Doug Duncan, Lynn Slagle

People have lived in the desert Southwest for thousands of years. To survive in this arid land, early settlers had to develop special skills and adapt to a desert-based way of life. Today, communities throughout the region face a similar challenge: learning how to grow sustainably while conserving water and functioning ecosystems.

This part of the country has an old saying: "Whiskey's for drinkin' and water's for fighting." There are no easy answers for managing water resources in the arid Southwest, but cooperative approaches have made fighting unnecessary. In southeastern Arizona, 21 government agencies and private organizations have banded together as a group to ensure that the region will continue to have an adequate ground water supply for area residents and the natural resources of the San Pedro River. They call this group the Upper San Pedro Partnership.

The purpose of the Partnership is to cooperate in identifying, prioritizing, and implementing policies and projects to assist in meeting water needs in the Sierra Vista Subwatershed of the Upper San Pedro River Basin.

The Challenge

The San Pedro is considered one of the most significant perennial undammed desert rivers in the United States. It provides important habitat for almost 400 species of migratory birds, 80 species of mammals, and 40 species of reptiles and amphibians. Many of these animals rely on the riparian vegetation of the Bureau of Land Management's San Pedro Riparian National Conservation Area (SPRNCA), which Congress designated in 1988. This area includes marshland, cottonwood-willow forest, mesquite forest, and various shrub lands. The water stored in the aquifer supports this vegetation and the perennial flow of surface water.

The Upper San Pedro River Basin and the San Pedro River are home to several listed species and provide suitable or potential habitat for several more. The river provides most of the occupied habitat for the endangered Huachuca water-umbel (Lilaeopsis schaffneriana var. recurva). This small, cryptic, semi-aquatic plant has 33 miles (53 km) of designated critical habitat along the San Pedro River. The San Pedro River also contains critical habitat for two threatened fish species, the spikedace (Meda fulgida) and loach minnow (Tiaroga cobitis), and potential habitat for a host of other native fishes.

The Upper San Pedro Basin uplands provide significant habitat for the threatened Mexican spotted owl (Strix occidentalis lucida) and the nectar-feeding lesser long-nosed bat (Leptonycteris curosoae yerbabuenae). This endangered bat occurs seasonally in protected roosts on Fort Huachuca and the Coronado National Memorial. The watershed also provides potentially suitable but currently unoccupied habitat for species such as the black-tailed prairie dog (Cynomys ludovicianus) and the endangered northern aplomado falcon (Falco femoralis septentrionalis).

Average yearly rainfall in the subwatershed ranges from 14 inches (36 centimeters) in the valley to 36 inches (91 cm) in the Huachuca Mountains. Most of the precipitation fails as heavy, almost daily rainstorms between July and September. The period between the summer and winter rains is very dry.

About 70,500 people share the Sierra Vista Subwatershed with the San Pedro Riparian NCA. Residents of the city of Sierra Vista, Fort Huachuca, and the surrounding area depend on the same groundwater resources that support the river's riparian vegetation. The combined demand for water is currently greater than the area's natural recharge. Inter-agency consultations between the Department of the Army (for Fort Huachuca) and the Fish and Wildlife Service have estimated an annual water deficit of 5,000 ac-ft (6,167,500 [m.sup.3]). As a result of each year's deficit, the decrease in total water storage since about 1940 is about 100,000 to 200,000 ac-ft (123,350,000-246,700,000 [m.sup.3]. This change is reflected in the continuing decline of the water table in some areas.

Without an adequate long-term water supply, neither the people of the area nor the river will thrive. The Partnership and its members are dedicated to meeting the long-term groundwater needs of both residents and the San Pedro River. Responsible use of groundwater involves managing it in a way that can be maintained for an indefinite period of time without causing unacceptable environmental, economic, or social consequences.

Balancing the needs of the San Pedro River with the needs of current and future residents must also take into account the framework of state and federal legal issues and statutes that pertain to groundwater withdrawals from the upper San Pedro River basin. These include:

* Gila River Adjudication and Sub-flow Technical Report: Arizona Department of Water Resources;

* Arizona Groundwater Management Act;

* Arizona Corporation Commission Certificate of Convenience and Necessity issued to private water utilities;

* SPRNCA enabling legislation;

* National Defense Authorization Act of 2004-Section 321;

* Sikes Act;

* Federal Land Policy and Management Act;