This graphic from the California Water Atlas (1979) represents the water flows of major rivers in California. The yellow figures represent the actual flow measured in a single year, with the peak typically occurring in spring. The corresponding blue figures represent the estimated flow of that river in the absence of dams or other human modifications. California Governor’s Office of Planning and Research, courtesy David Rumsey Map Center.

California’s Liquid Assets: Tracing the Water that Powers the World’s Sixth-Largest Economy

The history and economy of California are inextricably tied to water. Fortunes hinge on where it falls, where it’s diverted to, and who decides how it’s used.

The following is an excerpt from All Over The Map: A Cartographic Odyssey by Betsy Mason and Greg Miller, published in October 02018 by National Geographic.

“This book sets out to tell the biggest story in the richest, most populous state in the Union.” So begins the foreword to a surprisingly ambitious government publication, the California Water Atlas, published in 1979 by the state Governor’s Office of Planning and Research.

The atlas attempted to distill one of the most complex and contentious issues in the state — water use — into a series of maps and data visualizations that any citizen could understand. The goal of its idealistic creators was to use cutting-edge cartography to better inform the public about the water policy issues confronting the state.

A massive blue cylinder represents Lake Tahoe on this graphic of California’s lakes and reservoirs. The lake, one of the deepest in the world, holds 40 trillion gallons (151 trillion L) of water, dwarfing the state’s other lakes and reservoirs. California Governor’s Office of Planning and Research, courtesy David Rumsey Map Center.

The history and economy of California are inextricably tied to water. Fortunes hinge on where it falls, where it’s diverted to, and who decides how it’s used. So do many of the state’s scenic natural features, from the glacial lakes of the Sierra Nevada to the once thriving wetlands of the great Central Valley.

The idea for the atlas arose from the office of the state’s young governor, Jerry Brown. Brown’s liberal leanings and tendency to embrace the unconventional had earned him the moniker “Governor Moonbeam” from his more conservative critics. One of Brown’s advisors was counterculture hero Stewart Brand, the creator and editor of the Whole Earth Catalog, a progressive magazine and guide to political action. Brand was instrumental in getting the water atlas project off the ground.

The goal was to educate people about where the state’s water came from and how it was being used, Brand says. He insists there was no political agenda. “There were no ‘shoulds,’” he says — no prescriptions about what ought to be done. “The book could be used by someone on any side of the issue to get the facts.”

The entire project — from wrangling the data from various state and local agencies to creating the maps and graphics — was done in just 15 months. It was an amazing feat, especially in the days before computers.

This map of California’s waterways as they existed before significant human intervention was based on historical maps made between 1843 and 1878, when most parts of the state were relatively untouched by settlers. California Governor’s Office of Planning and Research, courtesy David Rumsey Map Center.

The atlas begins with the basics of where water falls as rain and snow and includes several maps like the “Virgin Waterscape” map (see above) that depict the state’s lakes, rivers, and wetlands before humans altered them. It goes on to sketch the history of how inhabitants of the state began to alter that picture in the 19th century as they diverted river water, first for mining and later to meet the needs of a burgeoning agricultural economy and fast-growing cities like San Francisco and Los Angeles.

Several chapters explore the economics of water, including which industries are the heaviest users (petroleum and coal mining, by a wide margin) and the relationship between cost and consumption in urban areas. The graphics, with their groovy 1970s color schemes, may look crude compared to modern data visualizations, but the creative displays of maps and data were groundbreaking in those precomputer days.

These pages from the atlas show five agricultural areas in the state, each represented by two long maps. The top map in each pair shows the type of crops grown there, the bottom one how much irrigation water was applied. California Governor’s Office of Planning and Research, courtesy David Rumsey Map Center.

The digital age had not quite dawned, but it was getting close. William Bowen, a young geography professor at California State University, Northridge, headed the small team of cartographers. Bowen says one breakthrough came when he happened on a new model calculator from Texas Instruments that could do cube roots. That made it possible to quickly calculate the right dimensions for the many three-dimensional graphics — though someone still had to use a ruler to measure them out and mark them on the page.

The atlas was well received when it came out, winning plaudits from cartographers and water wonks alike. The book originally sold for $20, and the first print run quickly sold out. It was almost too nice for its own good, says Brand. “We wound up with a book that immediately found its way into the rare book rooms of libraries,” he says, instead of becoming the continually updated, easily accessible document he had hoped for. If you’re lucky enough to find a copy for sale today, it will probably cost a few hundred dollars. As far as Brand is concerned, that’s a pity. “We inadvertently created a collector’s item instead of a political tool,” he says.

The above is an excerpt from All Over The Map: A Cartographic Odyssey by Betsy Mason and Greg Miller, published in October 2018 by National Geographic.

Learn More:

  • In 02013, there was an effort to make an interactive digital water atlas inspired by the original. The project has since fizzled out. The original vision for the California Water Atlas still hasn’t been realized, even though the need for it would seem to be as great as ever. Read Greg Miller’s WIRED profile of the proposed atlas here.
  • Explore the full atlas online at the David Rumsey Map Center.


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