Geomedia offers each month's book reviews, list of new books, book ordering information and new maps. 

Check out this month's On the Web links, your connection to earth science friendly Web sites. The popular Geomedia feature now available by topic.

Book Review:
Water Follies: Groundwater Pumping and the Fate of America’s Fresh Waters

A new map for North America
U.S. Geological Survey maps

Water Follies: Groundwater Pumping and the Fate of America’s Fresh Waters
by Robert Glennon. Island Press. (2002). ISBN 1-55963-223-2. Hardcover, $25.

William M. Alley

Groundwater is a hidden resource, difficult to study and also difficult to explain to a lay audience. As a result, groundwater remains neglected in the popular literature. “No one has ever watched a sunset or gone fishing on a body of groundwater,” former Secretary of the Interior Bruce Babbitt reminds us on the back cover of the book. Moreover, although many people know the expression by Ben Franklin that, “When the well’s dry, we know the worth of water,” relatively few people know that groundwater pumping also affects streams, lakes, wetlands and springs; these issues receive very little press. Robert Glennon’s book, Water Follies, sets to turn this situation around.

The book begins with the search of the bottled water industry for new sources of water, a search that we learn is not without controversy. After dipping into a discussion of water law and the history and uses of groundwater, Glennon takes us on a travelogue of a dozen stories that serve as case studies of the relationship between groundwater pumping and surface-water resources. We read about retirement homes built on depleted lakes in Florida, concerns about the drying up of sacred springs in Arizona, the effects of urban sprawl on river flow in Massachusetts, groundwater as the source of the famous River Walk in San Antonio and the challenges of providing water to tourists at the Grand Canyon. The stories provide a glimpse of modern-day water wars in places like the Upper San Pedro River basin in Arizona and the Apalachicola-Chattahoochee-Flint River basin in the southeastern United States.

Throughout the book, the author reminds us of the human capacity to ignore reality, in this case the reality that pumping groundwater has consequences. But he also acknowledges that the realities of groundwater can be difficult to see. For example, Glennon notes, it takes a rather sophisticated understanding to grasp how pumping municipal wells 10 miles from the San Pedro River is intercepting water that otherwise would reach the river.

Glennon dug deep into the background of many of his stories to bring us colorful personalities and quotes accompanied, at times, by wry commentary. Each chapter includes a map to orient the reader, and a substantial bibliography ends the book. A glossary helps the lay reader recall some of the key terms.

The book covers a lot of ground. At the same time, given the topic, and given that Glennon is a professor of law and public policy at the University of Arizona, I would like to have read more about the legal issues of conjunctive use of groundwater and surface water.

The book’s title reflects a tendency to dramatize the issues. For example, Glennon makes periodic references to “environmental catastrophes” and “disastrous effects,” and emphatically states “the country cannot sustain even the current levels of groundwater use, never mind the projected increase.” This statement is certainly true in some areas, but not in many others.

Lacking a specialization in hydrology, Glennon generally does a good job at presenting hydrologic concepts, with some exceptions in the detailed descriptions. For example, I found that the Humboldt River case study too readily dismissed geologic complexities and referred erroneously to a water table “some 1,500 feet below the river bottom.” Although such depths from the land surface to the water table might exist at the higher locations of the mine dewatering, the depth to the water table at the river would be much shallower.

In the final chapter, Glennon emphasizes that “a complete misunderstanding of hydrology has been memorialized in many states, where groundwater and surface water are legally two unrelated things.” He proposes eight avenues for reform of state laws and regulations. Included among these are simple conservation measures that are easy to administer and implement. Others are more draconian, such as imposing an extraction tax on water pumped from any well within a certain distance of a body of surface water. Some of his proposals, such as establishing minimum streamflows, are easier said than done, simply from a scientific point-of-view. Glennon also recommends collecting better information about the number of wells drilled in each state and how much water they pump, but does not address the importance of long-term monitoring of the resource. Nevertheless, it is to Glennon’s credit that he proposes solutions instead of just describing the problems.

Overall, this book makes for interesting reading, fills a gap in the environmental literature, and surely will draw attention to the long-term effects of groundwater pumping on our streams, lakes and wetlands. Despite the author’s advocacy stance in many of the stories, the book serves to raise consciousness about a long-term environmental issue associated with the wise use of one of our most precious natural resources.

Alley is chief of the Office of Ground Water for the U.S. Geological Survey, where he has long emphasized the importance of understanding the interactions of groundwater and surface water.

Back to top
A new map for North America

Since 1945, the United States, Canada and Mexico have been collecting magnetic data. Using airborne or offshore instruments, they have assembled data sets of magnetic anomalies, which reflect variations in the distribution and type of magnetic minerals in Earth’s crust. Because they detect magnetism in the bedrock, magnetic anomaly data provide a means of “seeing through” nonmagnetic rocks and cover — such as vegetation, soil, desert sands, glacial till, man-made features and water. The underlying variations in magnetism can reveal lithographic variations and structural features such as faults, folds and dikes. For example, abrupt changes of magnetism across a linear path can indicate the presence of a fault.

The United States and Canada have used their data to produce magnetic anomaly maps; but overall, the mapping efforts of the three countries have been disparate and some areas have remained unmapped. Recognizing a growing need to consolidate and digitize these data, these three countries have updated their data sets and combined them to produce the magnetic anomaly database and map of North America. These products are the results of cooperation among the Geological Survey of Canada, the U. S. Geological Survey and Consejo de Recursos Minerales of Mexico.

The new map supercedes the Magnetic Anomaly Map of North America that the Geological Society of America’s Decade of North American Geology (DNAG) program produced in 1987. The U.S. portion of the DNAG map was based on a 1982 magnetic anomaly map. The Canadian component was based on a 2-kilometer grid covering 70 percent of Canada. The map did not include data for Mexico. As a result of past compilation problems for the United States and recent major improvements in data coverage, compilation of a new digital database covering North America was encouraged by the scientific community.

The new map differs from the DNAG map in the extent of coverage and in the treatment of data. New surveys were added for the 2002 map. Coverage for Mexico is nearly complete, and many of the gaps for the United States and Canada are filled. For the new map, data from analog maps were digitized, and data from both analog and digital surveys were then digitally merged. The result is a map that features almost complete coverage at much finer resolution than the 1987 DNAG map.

The database and map are powerful tools for evaluating the structure, geologic processes and tectonic evolution of the continent and may also help to resolve societal and scientific issues that span national boundaries. The magnetic anomaly map provides a view of continental-scale trends not available in individual data sets, helps link widely separated areas of outcrop and unifies disparate geologic studies. Understanding the regional geology of the continent can provide information useful for a wide variety of applications, such as making mineral and energy resource assessments, investigating landslide hazards and earthquakes, and conducting hydrologic and environmental studies.

NORTH AMERICA. Magnetic anomaly map of North America by the North American Magnetic Anomaly Group. Sponsored by the Geological Survey of Canada, U.S. Geological Survey and Consejo de Recursos Minerales de Mexico. 2002. Scale 1:10,000,000. One color sheet 57 X 40 inches with 31-page text. Available free online, or for $7 from USGS Information Services.

Back to top

U.S. Geological Survey

Other new maps from the U.S. Geological Survey are:

I-2760. COLORADO. Evolution of the landscape along the Clear Creek Corridor, Colorado — Urbanization, aggregate mining, and reclamation by Belinda Arbogast, D.H. Knepper, R.A. Melick and John Hickman. 2002. Two color sheets 56 X 40 inches with 41-page text. Available for $14 from USGS Information Services.

I-2592. WASHINGTON. Geologic map of the Sauk River 30 X 60 minute quadrangle, Washington by R.W. Tabor, D.B. Booth, J.A. Vance and A.B. Ford. 2002. Scale 1:100,000. Sheet 1 color 53 X 42 inches; sheet 2 color 36 X 25 inches; includes 67-page text. Available for $14 from USGS Information Services.

I-2772. VENEZUELA. Debris-flow and flooding deposits in coastal Venezuela associated with the storm of December 14-16, 1999 by G.F. Wieczorek, M.C. Larsen, L.S. Eaton, B.A. Morgan and J.L. Blair. Prepared in cooperation with the U.S. Agency for International Development. 2002. Scale 1:25,000. Two color sheets 50 X 40 inches. Available for $14 from USGS Information Services.

To order USGS maps, contact USGS Information Services, P.O. Box 25286, Denver, CO, 80225. Phone: 888/ASK-USGS (888/275-8747).

Back to top

Randall Orndorff compiles the Maps section and is the associate program coordinator for the USGS National Cooperative Geologic Mapping Program. E-mail him at

The author thanks Viki Bankey of USGS for contributing to discussion of the magnetic anomaly map of North America.


Geotimes Home | AGI Home | Information Services | Geoscience Education | Public Policy | Programs | Publications | Careers

© 2018 American Geological Institute. All rights reserved. Any copying, redistribution or retransmission of any of the contents of this service without the express written consent of the American Geological Institute is expressly prohibited. For all electronic copyright requests, visit: