U.S. GEOLOGICAL SURVEY MIDDLE RIO GRANDE BASIN STUDY--PROCEEDINGS
OF THE THIRD ANNUAL WORKSHOP, ALBUQUERQUE, NEW MEXICO, FEBRUARY
                         24-25, 1999

                  Edited by James R. Bartolino

                           Abstract

Approximately 40 percent (about 600,000 people) of the total
population of New Mexico lives within the Middle Rio Grande Basin, 
which includes the City of Albuquerque. Ongoing analyses of the 
central portion of the Middle Rio Grande Basin by the U.S. Geological
Survey (USGS) in cooperation with the City of Albuquerque and 
other agencies have shown that ground water in the basin is not as 
readily accessible as earlier studies indicated. A more complete 
characterization of the ground-water resources of the entire Middle
Rio Grande Basin is hampered by a scarcity of data in the 
northern and southern areas of the basin.

The USGS Middle Rio Grande Basin study is a 5-year effort by the 
USGS and other agencies to improve the understanding of the 
hydrology, geology, and land-surface characteristics of the Middle
Rio Grande Basin. The primary objective of this study is to 
improve the understanding of the water resources of the basin. Of 
particular interest is to determine the extent of hydrologic
connection between the Rio Grande and the Santa Fe Group aquifer. 
Additionally, ground-water quality affects the availability of 
water supplies in the basin. Improving the existing USGS-constructed
ground-water flow model of the Middle Rio Grande Basin will 
integrate all the various tasks that improve our knowledge of the 
various components of the Middle Rio Grande water budget. Part 
of this improvement will be accompanied by extended knowledge of 
the aquifer system beyond the Albuquerque area into the northern 
and southern reaches of the basin. Other improvements will be 
based on understanding gained through process-oriented research 
and improved geologic characterization of the deposits. The USGS 
and cooperating agencies will study the hydrology, geology, and 
land-surface characteristics of the basin to provide the scientific
information needed for water-resources management and for managers 
to plan for water supplies needed for a growing population.

To facilitate exchange of information among the scientists working
on the Middle Rio Grande Basin study, yearly technical meetings
have been held for each of the first 3 years of the anticipated 
5-year study. These meetings provide an opportunity to present 
research results and plan new field efforts. This report documents 
the results of research presented at the third annual technical 
workshop held in Albuquerque, New Mexico, February 24-25, 1999.

The report is organized into this introduction and five chapters 
that focus on Middle Rio Grande Basin study investigations in 
progress in the Middle Rio Grande Basin. The first chapter 
describes geographic data and analysis efforts in the basin. The 
second chapter details work being done on the hydrogeologic and 
geologic framework of the basin. The third chapter describes 
studies on ground-water recharge in the basin. The fourth chapter 
provides details on the research on the ground-water flow system 
in the basin, including modeling efforts. The fifth chapter is 
devoted to an overview of New Mexico District Cooperative Program 
studies in the basin.

The information in this report presents preliminary results of an 
evolving study. As the study progresses and individual projects 
publish their results in more detail, the USGS hopes to expand the 
scientific basis needed for management decisions regarding the 
Middle Rio Grande Basin.
 
Abstract for Open-File Report 99-203