California's Flood-Control Challenge

For reinforcement of vulnerable levees, the governor has won approval for billions in public financing. Will it be enough to avert an infrastructure breakdown?

by Michael Arndt

Since the I-35W bridge collapsed into the Mississippi River on Aug. 1, killing at least five people, politicians at every level of government have refocused attention on how to adequately maintain the infrastructure that supports the nation's $13 trillion economy. While inspectors fanned out to reexamine 750 bridges of similar design, the Senate passed a long-stalled bill the next evening creating a commission to assess the condition of the nation's infrastructure to judge which portions needed the promptest repairs.

But elected officials, like their constituents, have short attention spans. People generally rail against paying higher taxes, too, especially on outlays that are no longer headline news, or have no immediate or direct impact on their own well-being.

In California, however, the long-term commonweal seems to be winning out as authorities race to avert an infrastructure breakdown that might be more calamitous than hurricane-ruined New Orleans: overflowing rivers that could, at virtually any moment, imperil as many as 500,000 people, the nation's richest cropland, and the water source of the majority of the state.

Fragile Infrastructure

Using New Orleans as a goad, Governor Arnold Schwarzenegger has rallied the public, persuading voters that they need to spend billions now on flood control, or they will pay much more later. Reinforcing piles of dirt and rock along riverbanks—infrastructure about as basic as it can get—has become a unifying cause.

"This is not one of those worry-today, forget-tomorrow issues," says Martin McCann Jr., president of a Menlo Park (Calif.) civil-engineering consulting firm, and technical manager of a state-funded project assessing how vulnerable a critical 1,600-square-mile triangular piece of the state is to flooding. Still, he adds, "It may be too little, too late."

Lawrence Roth, deputy executive director of the American Society of Civil Engineers, calls the situation scary. "It's got to be one of the more fragile infrastructure systems in the country right now," he says.

Fertile, Troubled Land

Though levees are almost singularly associated with the Mississippi River, California has more than 2,600 miles of berms embanking rivers and sloughs that fan out from the San Pablo Bay northeast of San Francisco up to Sacramento and Stockton. Before the California Gold Rush, much of this so-called delta was marshland. But as settlers discovered how rich this peaty soil was, they walled off more and more acreage to protect it from spring floods and turned it into farmland, and then communities.

Today this reclaimed land, bigger than the state of Rhode Island, is the most productive farmland in the world, filling grocery aisles with more than $32 billion of vegetables, milk, and meat a year. It is also home to some 2 million people, more than the population of greater New Orleans before Hurricane Katrina hit in 2005. And its mountain-fed rivers provide drinking water for an estimated 23 million people, or 2 of every 3 in California, thanks to aqueducts that stretch from the delta to the outskirts of metro Los Angeles 350 miles away.

Problem is, much of this landscape is in danger. Many of its levees are simply mounds of river muck, piled originally by shovel and wheelbarrow in the 1800s and never designed for long-term protection of homes and other structures. Moreover, the drained land has subsided, leaving huge tracts 15 or 20 feet below sea level.

When the Levee Breaks

Over the last century, California's levees have failed on average once every 7.5 months. Sometimes the breaks are foreseeable, coming, for instance, after a record spring rainfall. Other times, they just seem to happen. In 2004, there was a "sunny day" breach, when a levee gave way without warning on a delta island called Jones Tract; water from the surrounding estuaries quickly inundated 12,000 acres.

These islands—dozens of earth-walled plats separated by narrow channels—remain mostly farmland today.