U.S. Geological Survey middle Rio Grande basin study; proceedings of the third annual workshop, Albuquerque, New Mexico, February 24-25, 1999

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.