Introduction
In most areas in the Middle Rio Grande Valley, water leaks from the Rio Grande and is used by riparian vegetation, is intercepted by riverside drains, or moves to the Santa Fe Group aquifer system. Cochiti Dam, which is used for flood control and diversion of water, and three diversion structures (Angostura, Isleta, and San Acacia) have modified the river system in this valley. Riverside drains also have modified the river system and were constructed in the 1930’s to intercept water leaking from the river and to dewater land adjacent to the river so it could be used for agriculture. Water at the four diversions flows from the diversion points to fields through an interconnected canal and drain system. The major water use is irrigation for crops and riparian vegetation. Unused water is returned to riverside drains and then to the river for reuse or transport downstream. Some water applied to fields percolates to the Santa Fe Group aquifer system or returns to the drain system via alluvial and basin-fill deposits. Diverted water also leaks through canals to the aquifer system. The proposed study will begin a systematic data-collection program in the Middle Rio Grande Valley; the data will include surface-water and ground-water levels. These data may be used for future surface-water and (or) ground-water studies.

Problem
The river leakage that occurs from the Rio Grande has been determined in previous studies by estimating hydraulic head at points along the river and riverside drains within the Middle Rio Grande Valley. Resulting hydraulic gradients between the river and riverside drains and “best fit” horizontal hydraulic conductivity values were then used to estimate river leakage. Continuous, multi-year hydraulic-head data of the river, riverside drains, and in the shallow aquifer system, used for calculating river leakage on both sides of the river, are not currently available. Horizontal and vertical gradients and the direction of ground-water flow between the river and riverside drains, and between the riverside drains and adjacent fields cannot currently be accurately determined.

Objectives
Objectives of this study are to:
1. Establish a continuous, multi-year surface-water data-collection network along the Rio Grande and riverside drains in the Middle Valley.
2. Establish a continuous, multi-year ground-water-level data-collection network adjacent to the Rio Grande and riverside drains in the Middle Valley.
3. Provide these data to the public on the U.S. Geological Survey New Mexico District Public Webpage.

Scope
In 2003, a cross section was established at the Rio Bravo Bridge. Surface-water and ground-water-level data from this site are currently available and can be accessed by clicking on Surface-water levels -Hourly values and Ground-water levels -Hourly values.
In 2004 and 2005, seven additional cross sections will be established in the Albuquerque area. Cross-section locations include the Alameda, Paseo del Norte, Montano, I-40, Central, Barelas, and I-25 Bridges. From 2005 to 2007, additional cross sections will be established from Cochiti Dam to Bernalillo, I-25 to Bernardo, and Bernardo to San Acacia. The cross sections will use monitoring wells (piezometers) for ground-water-level data collection and streamflow-gaging stations for surface-water-data collection.

Approach
Monitoring wells will be located on both sides of the river at each cross-section. Gaging stations will be located on the east and west riverside drains and the river. The monitoring wells will be classified based on depth: deep wells, screened about 50 feet below the water table; intermediate wells, screened about 15 feet below the water table; and shallow wells, screened at the water table. The screened intervals will be 5-feet long. The wells will be placed in three configurations: a triple completion, which will consist of a deep, intermediate, and shallow well; a double completion, which will consist of an intermediate and shallow well; and a single completion, which will consist of a shallow well. A triple completion will be placed about 1,500 feet away from the river; a double completion will be placed on one side of the drain and a single completion on the other side of the drain; a triple completion will be placed in the bosque; and, a double completion will be placed adjacent to the river. This pattern will be repeated on the opposite side of the river.

Benefits
The data-collection program will benefit the Middle Rio Grande Valley and New Mexico by documenting present and future Rio Grande and riverside drain stage and shallow aquifer water levels. A database containing Rio Grande and riverside drain stage and shallow aquifer water levels recorded over a number of years may benefit present and future quantitative surface-water and (or) ground-water studies. Ground-water levels within the bosque may be used by biologists and others involved with restoration activities.