I appreciate the opportunity to address this legislative hearing. Today, I want to lay out some of the risks that we are facing in the Bay-Delta system so we can collectively start working on a solution.
We have chosen to illustrate these challenges by developing a failure scenario to show what would happen in the event of a major earthquake in the Delta. Professor Jeffrey Mount has done a good job of starting to expose some of the risks. The scenario I will present today takes that risk and moves it to the next level to show the actions we as a state would take in response to such a disaster and then, what happens over time.
The Delta is a water supply for more than 22 million Californians. It supports million acres of agricultural land. The direct economic use of these waters amounts to about $400 billion dollars of annual domestic product, with the indirect impact is much larger. There are more than 400,000 people living in the region and it is home to 500 species of wildlife. Something that is often overlooked is tremendous infrastructure in the Delta -- highways, water and petroleum pipelines, power distribution system, railroads, and the deep water port.
To illustrate the risks to this system, we chose an earthquake scenario as opposed to a classic flood scenario. There has been a lot of emphasis on PL 84-99, which would upgrade the levees at an estimated cost of $1.3 billion. But while this might have the effect of reducing the frequency of Jones Tract-types of failures, it has almost no impact on reducing seismic risk in the Delta. That is because the basic foundations of these levees have evolved over time as opposed to being engineered.
In earthquake, there will be liquefaction of the soils. The building illustrated in this slide simply sank into the ground after an earthquake in Japan because of liquefaction. Those are the kinds of foundations we have under many of the levees in the Delta system. This cross section is an excellent example of how the levees are not actually levees, but dams.
The Delta is significantly different from the levee system in the Central Valley. Most of the levees in the Sacramento system are dry most of the year. They only have water pressure against them during the flood season. In the Delta, the levees constantly have water against them. None of these levees would ever meet the standards we have for dams in California.
The Bay Delta region is a seismically rich area. That is why we have chosen to illustrate what happens not in a classic flood event, but rather a seismic induced levee failure of these systems. And since they are dams instead of levees, whenever the earthquake happens, you can have a failure of the system.
The scenario that we picked is a magnitude 6.5 earthquake near the western edge of the Delta. From the previous slide, you can see there are a number of active and suspected faults that could trigger this.
When this has happened, our models show there would be 30 levee breaches resulting in the flooding of 16 islands. This is not a worst case scenario. We can work with seismologists and come up with something that is actually worse than this. This level of probability for this earthquake and failure is about a one in 300 year event. That is roughly equivalent to Katrina. Just because it’s a one in 300 event doesn’t mean we don’t need to worry about it. It can happen.
In addition to the 30 levee breaches, you may have 200 miles of levees that are weakened by slumping and cracking, leading to increased seepage and a much larger repair problem. This is a levee this is slumped near Moss Landing after the Loma Prieta earthquake. Our assessment is with an earthquake located closer to the Delta, we would have this kind of slumping throughout the area.
When you have the break, a huge gulf of saline water runs into the Delta. Initial estimates are that about 300 billion gallons of water -- or close to a million acre feet -- would flow in during the first few days.
The most immediate near term impact would be an inundation of homes and agricultural land. There would be an immediate impact on water exports for Contra Costa, the State Water Project, Central Valley Project – all of which would cease immediately and remain shut down for the foreseeable future. Also because of the levees that might fail, we are assuming the failure of the Mokelumne Aqueduct which supplies the East Bay Region.
The other issues that tend to get overlooked when we get into the Delta water discussion is the expected failure of Highway160 and Highway 12, both of which would be inundated with water. Also of concern are ruptures of many natural gas and petroleum pipelines that run through the Delta, as well as those systems that would be voluntarily taken out of service because of the risk associated with leaving them operational. We saw that happen on Jones Tract. Additionally, you would expect erosion of railroad embankments and cessation of rail traffic across the Delta for some period of time.
The result would be major transportation disruption in the Bay Delta region. People who normally would use those highways for commerce or transit would try to switch to other highways and thus add to the crowding.
Anther issue is that, because of the earthquake and rushing of water, the dredged deep water ship channel would fill and the Port of Stockton would be closed for some period of time. With a deep water channel, there is constant dredging to keep it open. A seismic event, followed by the flow of water, would probably fill in that material.
In those initial impacts, we expect 85,000 acres of agricultural land and crops to be flooded immediately, and as many as 3,000 homes to be inundated. Because of the scope of this situation, the state would need at least three major command posts set up. Initial activity would focus on rescue operations to find those who have been trapped by the events, followed by a more methodical effort of setting up emergency management system teams, mobilizing the California Department of Forestry and California Conservation Corps crews, about 1,500 people, to start trying to preserve the levees that remain by protecting them with plastic and materials. One thing to note that is Jones Tract had excellent access with a road all the way around, allowing us to bring trucks in. Many of the other Delta islands do not have road access, requiring us to rely on air or boat. This would significantly delay the efforts to stabilize the situation.
We would also assign resources to protect the islands that did not fail in the earthquake. For those of you not familiar with the Delta, the top slide shows flood fights where there are boils that come up because of the water pressure on the flooded neighboring island pushes water to an unflooded island.
The state would try to get access to the 16 barge mounted cranes that are available in the Bay Delta region, although we suspect there would be other issues and we would be in competition for those limited number of cranes. Other cranes would likely need to come from Long Beach and Seattle, creating issues with transportation and transit time.
Our most optimistic projection is levee repairs would require at least 15 months. But because of the competition for heavy equipment and personnel, it is likely that it would be much longer than 15 months.
Southern California in particular would be drawing from their other water supplies and their reserves. Some entities have done a very good job with integrated resource management and could go for perhaps 36 months at a much reduced consumption rate. Other communities would have difficulties within the first year. Extreme water conservation measures would be put in place - such as banning outdoor water use and heavy reliance on groundwater basins, perhaps to the point of over drying basins and moving contaminant plumes leading to contamination.
There would also be a lot of effort to look at water transfers from other parts of the state to make sure we can minimize the economic impacts as much as possible.
The quality of the water coming out of the Delta would be substantially different from the current water quality, greatly increasing the cost of the treatment of the water supply. Within the Delta, we would have high brackish water content in the deep pools and remnant levee systems not just initially, but year after year.
The impact to endangered species and food chain are unknown. Chances are it would be beneficial to some species, and may actually eliminate others. The bottom line is this major earthquake will fundamentally change the Bay Delta ecosystem.
After the first year, we would expect to find that we were not able to close all the breaches. The state just would not have the resources to deal with wave fetch issues that would be happening. It is unlikely that we would be closing all the breaches after that point in time.
Within that year, we would have to start dealing with levees that didn’t break but were substantially impacted by the earthquake events. There would be slumps and cracks, and as a result of the wind driven waves, the wave fetch would be eating away at 20 percent of the levees on nine islands. There would be more breaches that happen as a result.
Our relatively conservative estimate is after one year we’ve experienced about $6billion dollars in damage in repair costs, lost crops, economic output in southern California. That is probably a low estimate, and again this is not a worst case picture.
In terms of water supply response, after a year of efforts, probably only seven of the flooded islands could be saved. It is probably that we would not try to preserve the rest of the islands, but to restore some water supplies, we could put in rock barriers so you could move San Joaquin water to export facilities. It would take about a month and130,000 tons of rock to put in these barriers to reroute some of this water while the rest of the Delta remains highly saline.
Looking at long term costs and impacts, the amount of water coming out of the Delta will probably be cut by about two-thirds. This water would be of significantly lower water quality, meaning the treatment costs would be significantly higher, both from a salinity and an organic carbon content. Delta agriculture and San Joaquin Valley agriculture would be significantly impacted by the water shortage and the inundation in the Delta. Traffic in and around the delta region would remain impacted because of the inundation of two of the major highways.
Businesses around the Delta would be greatly impacted because of transportation issues. Job loss could reach 30,000, largely because of the agricultural impact. Overall, a relatively conservative estimate is that California’s economy, over a 5 year period, would have a $30 to 40 billion impact.
In terms of Delta natural resources, even after 18 months, much of the central Delta remains brackish, particularly because of the remnant levees and the pools that have been created. We know that there’s a significantly changed ecosystem, although we don’t know what ecosystem values would remain. We would expect recreation both in terms of boating and recreation fishing in the Delta to be substantially impacted by this activity.
We think it’s a plausible scenario of what could happen in the Delta.
The Department of Water Resources started down a different path in January of this year when we released the Flood Management White Paper. That report that identified a lot of the problems we have with the flood management system in the entire Central Valley, with some emphasis on the Delta in terms of prioritizing levees and developing a better emergency response plan.
We are developing an interim emergency response plan. This came up in the hearing that Senator Machado held after the Jones Tract failure. Those of you who followed the Jones Tract know that in the first 36 to 48 hours we were searching for authority to get contracts executed. We need to fix that so we have pre-existing authority to respond as quickly as we can, and pre-existing criteria of how we proceed once an island has been stabilized and needs to be recovered.
DWR has also initiated the Delta Risk Management Study. That was initiated in February to develop better technical and scientific information on the levee system, the risks and impacts, to develop a risk reduction strategy and to prioritize funding.
There are two main legislative initiatives on flood management reform in play. The first is Assembly Bill 1665, John Laird’s bill to make some fundamental changes in flood management in the Central Valley that will also be beneficial to Delta issues. The second bill is Assembly Constitutional Amendment 13 by Assemblyman Harman which would modify Prop 218 to make it easier for locals to raise funds for their flood system maintenance activities. Finally and perhaps most importantly\ given the discussion we’re engaging in today, the Delta levee evaluation by DWR and the Department of Fish and Game in response to Assembly Bill 1200 by John Laird’s bill which we see as an opportunity for a Delta vision and a Delta strategy.
It is our intent to use this disaster scenario to work with stakeholders and the state legislature in the context of AB 1200 to develop a very different approach to how we respond to reduce these risks which are real and which can take us to the same situation that New Orleans has experienced, if we don’t act now.
