Securing the California Delta's levees before a major earthquake [but let's not talk about that]

In the event of a major earthquake or flood and many levees failing simultaneously in California's Sacramento-San Joaquin River Delta, as many as 515,000 residents and 520,000 acres of land would be in immediate danger; the long term effects could be even more widespread, as nearly 28 million residents depend on the Delta for water and irrigation; California lawmakers have increasingly turned their attention to securing the Sacramento-San Joaquin River Delta's levees, but experts say that only little progress has been made

After witnessing the destructive potential of broken levees during Hurricane Katrina, California lawmakers have increasingly turned their attention to securing the Sacramento-San Joaquin River Delta’s levees so they can withstand a major earthquake. Observers say that little progress has been made.

The levees surrounding the Sacramento-San Joaquin River Delta hold back the largest estuary on the Pacific Coast of the United States, provide 76 percent of the fresh water supply used for drinking and irrigation in California, and keep major cities and infrastructure dry.

Miller McCune reports that in the event of a major earthquake or flood and many levees failing simultaneously, as many as 515,000 residents and 520,000 acres of land would be in immediate danger. The long term effects could be even more widespread – nearly twenty-eight million residents who depend on the Delta for water as well as irrigation for farm lands stretching as far south as San Diego would lose access to their major source of water for months or even years.

The U.S. Geological Survey (USGS) predicts a 63 percent chance that an earthquake of magnitude 6.7 or greater along the Hayward fault line will occur by 2038. The Hayward fault lies only forty miles west of the delta, while at least six other fault lines lie even closer.

Earthquakes are only part of a long list of dangers that threaten the levees. Rising sea levels, increased rainfall, and even beavers pose real dangers – it is believed that in 2004 a beaver caused a levee breach that took six months and more than $90 million dollars to clean up.

Geography, physics, and history have put a gargantuan strain on one of California’s most important pieces of infrastructure. Situated between the San Francisco Bay and the Sierra Nevada Mountains, the levees must protect against both the surging salt water of the bay and the fresh water rushing downstream from the mountains.

Engineer Jay Lund fears that the Delta could easily become a salty marsh. On Lundpredicted that if nothing is done, “the levees will fall down, the saltwater will come in, and you will not be able to pump water from the delta.”

Climate change is straining the levee on both sides with rising sea levels in the bay and a decrease in snowfall that has resulted in increased rain and engorged rivers. To make matters worse, much of the land protected by the levees actually rests as much as twenty feet below sea level.

As quoted by NPR, geologist Jeffrey Mount believes that “the delta of today is not sustainable even under today’s conditions, never mind climate change.”

For a levee that protects billions of dollars of investments and millions of lives, it is disturbingly poorly built. The levee system was not designed using modern engineering principles, instead it slowly evolved over time. Beginning in the 1850s the levees were first constructed by Chinese laborers using dirt to create space for farmland.

Over time the levee system grew in a piecemeal fashion to surround over 1,100 square miles and was forced to take on duties it was not originally designed for including providing freshwater for Californians as far away as Southern California and holding back water from the bay and rivers. The result is the current complex maze of levees that wind haphazardly across the Delta.

Many of the levees are built on a foundation of sand, a weak base in the event of an earthquake. To protect against seismic tremors and liquefaction, levees are being fortified with rock at their foundations. Unfortunately, this is a slow and incredibly expensive undertaking that would cost billions of dollars at a time when the California is facing a massive budget crisis.

Prospects for major improvements are bleak as CALFED, the federal-state agency tasked with managing the Delta, is experiencing significant budget shortfalls. After existing for only ten years, CALFED saw a projected budget shortfall of over $6 billion dollars in 2004.

Alternative sources of funding for repairs look slim as well. In the 2010 election cycle, an $11 billion dollar bond proposition which included $750 million for levee repair was pulled from the ballot due to fears that voters, hard hit by the recession, would reject it.

The prospects for a solution that will make a substantive impact on the levees look bleak. The latest attempt to address the Delta’s water issues is a proposed series of canal, tunnel, and pipeline projects – which have been dubbed the “periphery canal” for short – that would divert fresh water from rivers before it reaches the Delta and pump it to communities across California. The system will, in theory, be able to continue pumping fresh water in the event that the levees collapse. The periphery canal, however, even if successful, fails to address the fundamental problem of flooding due to failing levees.

Like repairing the levees, the stop-gap measure of building the periphery canal is fraught with political tension and may never occur. “[The canal] was political poison for about 20 years,” Mount says. “You simply did not talk about that as an option.” In 1982 a similar proposal to build a canal sparked an all-out political battle before it was eventually rejected by voters who believed it was an attempt by Southern California to steal water.

As in the past, the fate of the Sacramento-San Joaquin River Delta’s levees is at the mercy of the capricious political winds of California. The Delta and its water supply effects so many residents across the state, nearly everyone – from local residents to utility companies, from environmental groups to county governments, and from large businesses to state commissions – has a significant stake in what occurs, making it difficult to accomplish anything as every decision is subject to prolonged and heated political battle.

After the horrifying damage that flooding caused in Pakistan last summer and now most recently in Australia, where the cleanup could cost billions of dollars, it would serve California well to act quickly and overcome budget shortfalls and political infighting before the near- inevitable next earthquake occurs and broken levees cause devastating floods that will further ravage California’s economy, environment, and people.

... nearly twenty-eight million residents who depend on the Delta for water as well as irrigation for farm lands stretching as far south as San Diego would lose access to their major source of water for months or even years.

Let's all have one long media-led, collective, national pucker about nuclear accidents after the earthquake/tsunami in Japan.

Or could expect or elected leaders to think, prioritize and act.

Just sayin'.

The other day I heard a detailed interview with a journalist, originally from New Orleans, talking about the Katrina disaster and the poor conduct of the Army Corps of Engineers. He blamed both Ds and Rs for the human failures in New Orleans planning, but blamed the Corps for only building to a Category 3 hurricane level. He discussed several other potential disaster areas with Corps levees, and the Sacramento area was one of them. He wasn’t even talking giant earthquake or tsunami, just a major wind and rain storm as potentially disasterous. I wish I could remember his name and the title of his book.

I noticed in the Wall Street Journal that we've received a score of 'D' for our infrastructure - it might be good to do something about this before it's needed, unless being furiously outraged in flurries of public statements after something like Hurricane Katrina is more people's preference.

Naaaaaa......the easiest way to fix the problem with the levees is to force the California politicians to live below them.

That's really very funny on a number of levels. (The intellect of the average politician is already below sea level.) Gotta love FReepers for their quick wit.

Thanks for the laugh.

This whole paragraph is a lie from start to finish. There has been no rise in sea levels, snow pack in the Sierras has not diminished and our rain fall remains fairly constant year to year.

If we were allowed to build more dams on the rivers we could do away with the levees. The levee system was built way before the rivers were damned. It was found that the levees, working alone, could not keep back the floods year after year. Some years they worked others they did not. Sometimes it was possible to row between Sacramento and Stockton, a distance of about 50 miles. After the dams were built the floods were brought under control, but of course the greenies stopped the building of any new dams with the capacity to hold back the water and keep the rivers within their banks even in the winter. The solution is to build more dams and/or to start replacing the old dirt levees with new concrete(reinforced of course)levees. A combination of both would pretty much render floods in California obsolete.

Once the Delta Smelt moves into the flooded area that area is lost forever.

Well if you are living on one of those delta islands that have been farmed for 150 years then his 25 feet might be correct. This does show the problems of farming in the Midwest and the loss of topsoil. Look at the bright side. All those nice two stories out by the airport can be used as boat docks.

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