WATER-RESOURCES VITAL-SIGN MONITORING IN THE NATIONAL PARK SERVICE CHIHUAHUAN DESERT INVENTORY AND MONITORING NETWORK OF NEW MEXICO AND TEXAS

The Chihuahuan Desert Inventory and Monitoring Network (CHDN) is responsible for the inventory and monitoring of natural resources within Amistad National Recreation Area, Big Bend National Park, Carlsbad Caverns National Park, Fort Davis National Historic Site, Guadalupe Mountains National Park, Rio Grande Wild and Scenic River, and White Sands National Monument. Monitored resources within CHDN include surface- and ground-water quantity and quality.

Proposed water-resources monitoring requires identification of parameters that serve as vital signs reflecting the conditions of water resources within CHDN. The goals of vital-sign monitoring include: 1) determining the status of and trends in water resources, 2) providing early warning of the development of atypical hydrologic conditions, 3) improving understanding of the dynamic nature and condition of hydrologic systems, 4) providing data to meet legal mandates, and 5) providing a means to measure progress toward performance goals. Important water-resources vital signs identified by CHDN include: 1) Surface-water quality as determined by temperature, pH, specific conductance, turbidity, abundance of bacteria, abundance and diversity of aquatic macroinvertebrates, and concentrations of dissolved inorganic constituents, dissolved oxygen, and nutrients; 2) rates and frequencies of surface-water discharge; 3) sediment load and chemical composition; 4) lake and reservoir levels; 5) ground-water quality as determined by temperature, pH, specific conductance, and concentrations of dissolved inorganic constituents; and 6) ground-water levels. The CHDN water-resources vital-sign monitoring program is being designed to complement and benefit from monitoring efforts by the U.S. Geological Survey, the New Mexico Office of the State Engineer, the Texas Commission on Environmental Quality, the Texas Water Development Board, and the International Boundary and Water Commission.