Land Matters

Another New Orleans-style disaster is in the making in this country. Would you be surprised to learn it’s in the middle of California?

Houses built below sea level in California.

Well, it is. The Delta that forms where the Sacramento and San Joaquin rivers converge about 80 miles from the Pacific coast is a vast estuary where about 50 islands of low-lying but highly productive farmland are protected by 1,100 miles of levees. Recently, developers have moved to subdivide the islands and build thousands of suburban homes on what used to be farms. But look carefully at the photo above: Do you notice the river is higher than the houses? That’s because most of the new subdivisions are being built below sea level. Sound familiar?

Not surprisingly, the Gulf Coast disasters have awakened California to the danger those new home owners face. Governor Arnold Schwarzenegger wants the state to spend hundreds of millions of dollars to make the levees bigger and beefier. But will Schwarzenegger-style levees really protect the houses in the photo above? Consider this: The Delta lies on an earthquake fault and, when the next Big One rocks California, the peat soils of which the islands are composed could liquefy, causing even the most beefed-up levees to collapse.

Even without an earthquake, the new ’burbs are at risk. The levees are designed to protect against a 100-year flood, but what about a 200-year flood? A 500-year flood? To explore such questions, the Department of Landscape Architecture and Environmental Planning at UC Berkeley hosted a two-day conference in March, ReEnvisioning the Delta, that pulled in experts on everything from levees to public policy. There, Matt Kondolf, the department’s fluvial geomorphologist who helped organize the conference, calculated that, over the course of a 30-year mortgage, a home owner will have a 26 percent chance of being inundated by one of those monster floods.

Why is anyone building in these flood-prone areas, anyway? One reason is California’s lack of affordable housing. Another is the enormous profits to be made by home builders. Finally, there’s collusion at the political level: According to Kondolf, Schwarzenegger pocketed $2.5 million from just one Delta builder.

To me as an outside observer, building thousands of houses below sea level is tantamount to insanity. The only idea more loopy is to beef up the levees to encourage such building. But how to create a powerful constituency for other options for the Delta—such as calling a moratorium on home building and leaving all that rich farmland in production? Or what about the idea, proposed by Kondolf and others at the Berkeley conference, of declaring the Delta a regional “Central Park” for what will be, by 2050, a continuous ring of cities stretching from San Francisco to Sacramento to Stockton and back around?

Landscape architects don’t normally get involved in flood control, but a winning entry in Berkeley’s annual Tommy Church Memorial Design Competition, which I helped jury, suggests a way in which landscape architects might help build a constituency for options. Graduate students Elke Grommes, Mei Minohara, and Zachary Rutz created an eloquent graphic and written storyboard that evoked the quiet beauty of the Delta and showed why a regional authority should be created with the clout to protect it.

H. G. Wells once wrote that human history is a race between education and catastrophe. In the Delta, as in so many unique landscapes, the need for landscape architects who can step forward to articulate a vision for the future is needed more than ever.

J. William “Bill” Thompson, FASLA
Editor/bthompson@asla.org