Water supplies and population growth are on a collision course

By B. Meredith Burke

October 31, 2001

Earlier this month Gov. Gray Davis signed into law a bill that marks a milestone in California planning. The new law prohibits local officials from approving tracts of 500 homes or more unless there is proof of adequate water over at least the next 20 years, including long periods of drought.

Until now, cities and counties could approve residential and commercial construction without asking water agencies if they could meet new usage demands.

Sen. Sheila Kuehl, D-Santa Monica and sponsor of the SB 221, noted, "For the first time California law associates water-use planning with land-use planning." But is a 20-year planning horizon sufficient?

For decades California's demographic trends and water availability have moved at cross-purposes. Our state population has soared from 10 million in 1950 to 20 million in 1970 to at least 34 million today. Unless we purposely shift demographic course we will reach 50 million sometime in the mid-2020s.

The most recent California Department of Water Resources water plan, released in 1998, has a year 2020 planning horizon. Given existing facilities and programs, by then eight of the state's 10 hydrologic regions would be in water deficit in an average rainfall year, and all of them in a drought year such as experienced in 1991-92, a once-in-20-year drought.

Using likely management options (rationing, water conservation and recycling, improvement of the State Water Project supply reliability, etc.) reduces to one the number of regions in shortage in a normal year. However, in a drought year six of the regions including the Central Coast (stretching from San Luis Obispo to Santa Barbara) and all three in the Central Valley would experience shortage.

These projections may well be overly optimistic. An appeals court has found that the State Water Project can deliver only about half of the original entitlements to state contractors. The water plan assumes that all the urban best management practices identified in 1991 will be fully implemented by 2020. This would result in a demand reduction of about 1.5 million-acre-feet (maf) over the year 2020 demand forecast without such implementation.

Under the best case scenario, urban water demand is projected to grow from 8.7 maf in an average rainfall year in 1995 to 12 maf in 2020. For a drought year these figures become 9 maf and 12.4 maf. These projections reflect a population gain of nearly 50 percent -- from 32 million to 47.5 million between 1995 and 2020, a gain of one and one-half times the state's 1950 population.

Last spring a conference on "The Collapse of Complex Societies" was held in San Francisco. "Complex societies have been collapsing for 12,000 years -- or as long as they have existed," said Joseph Tainter, an expert on prehistoric American Indians at the Rocky Mountain Research Station in Albuquerque, N.M.

Presenters singled out two causes among the many that contributed to the downfalls of antiquity: too many people and too little fresh water. Given these preconditions, a prolonged drought or a change in climate would push these societies over the edge.

Tainter explicitly drew parallels between California's electricity crisis and perpetual quest for enough water, and societal-wrecking forces of yore.

To stave off the collapse of our complex society we should request planning exercises that invoke one-in-100-year and one-in-500-year droughts, the probable effects of global warming in California's latitudes, and a time horizon of 90 years (two population doubling times at the present rate).

Michael Dettinger, a climatologist at Scripps Institute of Oceanography, says that the historical record is vastly inadequate. Over the last 1,000 years, there have been two droughts of the severity of the one in the early '90s, that lasted 100 years. This signals a looming disaster.

Even if California accommodates 50 million people, Garrett Hardin, renowned UC Santa Barbara ecologist and professor emeritus, would say, "and then what?" Are we prepared to accommodate another 50 million state residents by 2070? And 100 million more by circa 2110?

State administrators should be demanding that Washington evaluate the role it plays in delivering us to an ever-more-precarious water supply situation and to ever-more-serious water battles between urban and agricultural users. California's survival hangs on halting population growth, which realistically means halting national population growth.

In 1972 the Commission on Population Growth and the American Future futilely urged Congress to adopt a national population stabilization policy. Eighty million people later, immigration -- both entrants and of increasing importance, births to immigrants -- has supplanted births to the native-born as the primary source of population growth.

Rethinking population policy necessitates rethinking immigration policy. The environment and water resources are indifferent to the source of population growth: they react only to sheer numbers.

Testing nature's limits only guarantees that in the not-too-distant-future collapse can and will happen here.

http://www.signonsandiego.com/news/uniontrib/wed/opinion/news_1e31burke.html

-- Martin Thompson (mthom1927@aol.com), November 01, 2001

Answers

And whatever we do, lets not consider the mass invasion from the south as a source of population pressure. Duh, I wonder why we're running out of water.

-- Guy Daley (guydaley1@netzero.net), November 02, 2001.

Certainly population pressures from the south are a large part of the picture. However, immigrees aren't the entirety of the problem. We native born types are also responsible for burying our heads in the sand, and not being forward looking enough to forecast what happens in a finite system when we try to have infinite growth.

Where do I apply for a 499 house subdivision, by the way?

JOJ

-- joj (jump@off.c), November 06, 2001.