The Sacramento Bee: By Jeffrey Michael and Robert Pykeis
Several new reports on the condition of the Sacramento-San Joaquin Delta levee system, the economic value protected by the levees and the consequences of levee failures create an opportunity to rethink what it means to “fix” the Delta.
Seismic upgrades to most lowland Delta levees would protect water supplies for a fraction of the cost of a tunnel or canal to transfer water to the Central Valley and Southern California. Upgraded, wide levees would also improve habitat by supporting appropriate vegetation. These improved levees, combined with expanded flood bypasses, would create a cost-effective, eco-friendly flood control system in the Delta.
In addition, fat seismic-resistant levees would help save lives in an emergency and protect other critical transportation and energy infrastructure that is overlooked in many discussions regarding the Delta.
The Delta Protection Commission recently completed an economic sustainability plan, as required by the 2009 Delta Reform Act. The plan found that Delta levees need significant new investment, but also found that the levee system is in far better condition than typically portrayed.
Several hundred million dollars have been invested by the state and local reclamation districts in improving Delta levees, and the performance of the system has significantly improved as a result. New maps and a new technical report from the state Department of Water Resources confirm the improved condition and performance of the levees.
This is in stark contrast to most news reports about the levees, which describe them as fragile, aging and deteriorating, and say their inevitable collapse will lead to a catastrophic loss in water supplies to Central Valley farms and Southern California.
According to this narrative, the best approach is to secure water supplies by building a peripheral canal or tunnel through the Delta, and that many levees should be allowed to fail or be removed as part of restoring the Delta ecosystem. The Bay Delta Conservation Plan follows this reasoning.
The Bay Delta Conservation Plan’s direct costs exceed $23 billion, not including interest and the cost to the Delta community. Despite its enormous cost, the plan does nothing to improve public safety and protect human lives, or guard against the most important economic consequences of a much feared earthquake-induced levee collapse.
The Delta Risk Management Strategy Phase 2 report was released by the Department of Water Resources in 2011 and found that disruption of water exports was only 20 percent of the economic loss from a large Delta earthquake, less than 2 percent of the loss from smaller, more common flood events, and zero percent of the loss of life from all Delta flood hazards.
Far greater economic losses would come from the loss of highways and railroads, homes and businesses, flood damage to energy infrastructure such as gas wells, pipelines and inter-regional electricity transmission lines, in-Delta crop losses and wastewater treatment plants and regional water supplies. Many of these economic disruptions would continue long after salt water was flushed out of the Delta and water exports to Southern California restored.
All of these impacts, including water export disruptions, would be substantially reduced by seismic levee upgrades in the Delta. That is why the risk management strategy Phase 2 report found levee upgrades had the highest benefit-cost ratio of Delta risk-reduction scenarios, including a peripheral canal that was assumed to cost one-third of the current estimate of $14 billion.
Rather than directing tens of billions of dollars to protecting against one part of the economic loss from a low-probability Delta disaster, it makes far more economic sense to invest an estimated $2 billion to $4 billion on improved levees that provide multiple economic and environmental benefits, and would save lives in a disaster.
Although the Bay Delta Conservation Plan is evaluating other alternatives, it is not currently examining seismic-levee upgrades as a component of an overall solution that would achieve the co-equal goals of ecosystem restoration and reliable water supply that are called for in the 2009 legislation.
Some critics label further levee investments as a “preservation of the status quo” approach. But the type of levees recommended in the economic sustainability plan would transform the Delta into a place with robust flood protection and dramatic environmental improvements along scenic tree-lined channels that provide improved habitat while boosting recreation and tourism in the Delta for all Californians.