Last June, 23 million persons throughout in southern California, as well as Santa Clara Valley, Contra Costa County, and other parts of California were cut off from their water supplies for several days when a Sacramento Delta levee on Jones Tract broke, apparently threatening to bring salt water into the delta from San Francisco Bay. As a precaution, the giant pumps that move water out of the delta were turned off, temporarily cutting off supplies to more than half of the residents of the state and farms throughout much of the San Joaquin Valley.
Is enough being done to prevent it?
Would a peripheral canal be a solution?
By Wes Starratt, Senior Editor
Published: July, 2005
Last June, 23 million persons throughout in southern California, as well as Santa Clara Valley, Contra Costa County, and other parts of California were cut off from their water supplies for several days when a Sacramento Delta levee on Jones Tract broke, apparently threatening to bring salt water into the delta from San Francisco Bay. As a precaution, the giant pumps that move water out of the delta were turned off, temporarily cutting off supplies to more than half of the residents of the state and farms throughout much of the San Joaquin Valley.
It was a real touch-and go situation, starting with an early morning call from the reclamation district on Jones Tract to the Dutra Group, possibly the only firm available with the dredges, barges, and cranes, as well as the bay-side rock quarry in San Rafael, and the experience to close breaches in delta levees. First there was a leak in the levee, then a breach, and soon an emergency call from the California Department of Water Resources (DWR) to Dutra to close the gaping breach as soon as possible, but even so, it took 27 days to completely close.
Chris Neudeck, principle of KSN Engineers in Stockton, represents many of the reclamation districts that own the levees in the delta. He commented, "We were looking at an initial flooding of 12,000 acres with 200,000 acre-feet of water (one acre, one foot deep), plus danger to another levee along Highway 4. If that levee was not raised, there was the threat of flooding another 40,000 acres of farmland together with shutting down the state and federal pumps for as much as 60 days."
To make matters even more precarious, the Mokelumne Aqueduct, carrying water across the delta to the entire East Bay, was also put in jeopardy by the flooding, as was a main line of the BNSF Railroad.
What caused the Jones Tract breach? Harry Stewart, Chief Operating Officer of the Dutra Group, said, "The levee was well maintained over the years, and that section had a good solid section. It didn’t appear to have any weaknesses. The most common theory is that it was a rodent or a beaver problem."
This was not the first beach of these old levees. In fact, there have been 162 levee breaches in delta over the past century. And, according to Ron Ott of the California Bay-Delta Authority, "We expect that to continue."
"The delta needs to be fortified. One must remember that these delta levees were built … they were not engineered … and they were constructed piece by piece, and bucket by bucket, over 100 years with peat soil, sand, and clay," said Stewart.
The condition of these levees is of considerable concern since the Sacramento Delta is geographically situated not only at the center of the state water distribution system, but is crossed by numerous oil and gas pipelines, electrical transmission lines, and utilities of all types.
Historically a salt water marsh, the delta, which lies to the west of Sacramento and Stockton, comprises an area of some 750,000 acres, with countless waterways and more than 60 islands, many of which are below sea level and protected by almost 1,000 miles of levees. The whole delta was once at sea level, but now when you drive out on the levees and look down 20 feet or more to ground level, you realize that these levees have become more like dams, holding back water for the entire year.
In fact, the delta has become California’s main source of fresh water, since precipitation from over 40 percent of the entire state drains into it from a geographical area stretching from as far north as Mt. Shasta to well beyond Yosemite Valley in the south. That encompasses the river drainage basins from the Sacramento to the San Joaquin, plus most rivers in between. In an average year, the volume of water flowing from this area into the delta is calculated at about 28 million acre-feet, or some 9 trillion gallons. Almost 75% of that water flows through the delta and into San Francisco Bay, but the balance is pumped through an extensive system of aqueducts and pipelines to the homes and farms of California.
Some 23 million persons, more than half of the state’s population, plus more than seven million acres of farmland throughout the central valley, depend on the delta as the prime source of water. But, the quality of delta water depends on keeping San Francisco Bay’s salt water out of the delta, and the ability to do that depends on almost 1,000 miles of unstable delta levees built of peat moss over the past 100 years on islands that are slowly sinking.
The delta plays a critical role in the State’s water supplies
Some 150 years ago, as the fever of the 1849 California Gold Rush subsided, attention turned to farming in the peat-rich soils of what was then a tidal salt marsh with islands and river channels. Over a period of years, levees were built from the soft peat moss, the islands were drained, and farming began. Today, the delta comprises almost a half-million acres of some of the state’s richest farmlands on about 60 islands, surrounded by sloughs carrying water to homes and farms throughout the state, as well as to the ocean through San Francisco Bay.
Over the years, the temptation of farmers and city dwellers to tap the fresh water pouring into the delta has been great. By the 1950s, the large-scale movement of fresh water from the delta began with the completion of the Delta-Mendota Canal by the Federal government to supply farms in the central valley. It was called the Federal Central Valley Project. Later came the mammoth State Water Project that included the Oroville Dam and the Feather River Project to provide additional water that would flow through the delta into the mammoth Banks Pumping Plant, and then southward in the 444-mile-long California Aqueduct, or in the South Bay Aqueduct serving Alameda and Santa Clara counties.
In the original plans for the State Water Project, some of that water was supposed to flow from the Sacramento River in the north around the delta, and not through it, in a cross-channel or peripheral canal, to the pumping plants in the south. However, that plan got bumped, possibly as a cost-cutting measure, and efforts to revive it have met with strong political resistance. So, water continues to flow through the precarious channels of the delta to the pumping plants in the south.
Levees, The Glue That Holds the Delta Together
The levees were built by Chinese laborers and delta farmers, not engineers, over a period of many years, on unstable foundations, using the peat soils native to the delta. It is the peat soil that causes problems for the levees and the islands. The material is weak and highly compressible; it blows away and gradually oxidizes, basically turning to carbon dioxide. As a result, the islands continue to subside at a rate of as much as 1 to 1 ½ inches per year. Many of them are now 30 feet below sea level. The original levees were built to a height of about four feet, but, as the islands have sunk, the levees have had to be increased in height and width.
According to Curt Schmutte, principal engineer of the State’s Dept. of Water Resources (DWR), "This subsidence is putting the state at greater and greater risk every year because of the added pressures that it creates on the levees; so, the consequences of a levee failure become greater with every inch of subsidence. I like to call this a ‘silent killer’ that is going on every day, but is imperceptible, even on a monthly basis … The present situation is not sustainable."
Up until now, levee breeches have occurred one or two at a time and it has been possible to make repairs without seriously impairing water exports from the delta. But, after a major levee break in 1983, it was deemed prudent to release additional water from Shasta Dam through the Sacramento River and into the delta, in order to prevent salt-water intrusion into the delta.
What would happen if the June 2004 levee break had triggered others, as it could have, during the rainy season? Or, if several of these old levees gave way at the same time due to tidal action, heavy rains, wind-whipped waves, or an earthquake on a nearby fault?
Saltwater could be drawn into the delta from the Bay, but then water supplies for over half of the state’s population and farmland would be in serious trouble, possibly for an extended period of time. The problem is serious; and it is real.
We asked Ron Ott, Delta /Regional Coordinator for the California Bay-Delta Authority (CalFed), about the magnitude of the levee problem. He responded, "One of our concerns has been voiced recently by Professor Jeffery Mount of UC Davis and BobTwist of UC Berkeley, members of our Integrated Science Board, who have concluded that ‘There is a 60% chance that, within the next 50 years, there will be a catastrophic event in the delta, either a flood or an earthquake, that will lead to multiple levee failures and island flooding.’"
We talked with Professor Mount, who claims that the odds for a catastrophic event are roughly "2-in-3" within 50 years and said, "There is the possibility that changes in the delta could be quite abrupt and cause wide-spread levee failures and multiple island failures," but unfortunately, "our planning for the delta and water supplies for the state is predicated on one flawed assumption, and that is that the delta will remain static into the indefinite future. My whole point is that it will not. Yet, all we have in place are emergency responses and a pittance of investment in maintaining the existing levees. The money that should be invested in the delta is going off to the Middle East."
Ron Ott of CalFed agreed. "It takes funding do anything in the delta, and we are short of funding."
Historically 50% of the funding for delta work has come from the state and only 7% from the federal government. Another 37% comes from local matching funds from cities and water districts, and 6% comes from water user fees. The state’s funding is largely through bond measures: Prop 204 in 1996, Prop 13 in 2000, and Prop 50 in 2002, but that funding is running out. Legislation is pending, at the State level, to provide additional funds.
How Many Agencies?
Another issue is the sometimes overlapping and confusing federal, state, and local responsibilities. On the state’s side, DWR has the primary responsibility for maintaining water quality in the delta, with the Department of Fish & Game serving a partner to ensure that there is no net loss of habitat. On the federal side, the US Bureau of Reclamation operates many of California’s water facilities such as Shasta Dam; and the US Army Corps of Engineers has broad responsibilities for flood control and maintaining ship channels through the delta to the ports of Sacramento and Stockton. The overall "umbrella" organization in the delta is CalFed, which tries to bring together a host of federal and state agencies, sort out responsibilities, and secure federal funding.
We spoke with Keith Coolidge, Communications Director for the California Bay Delta Authority, a separate state agency that was established to coordinate the implementation of the CalFed Program, who said, "The frustrating part is that state agencies can’t make decisions that are binding on federal agencies, and generally visa-versa. And no agency gives up its power to be part of the program. So, while the authority can make recommendations, the ultimate decision-making ability rests with the individual agencies in the state and federal governments, which don’t always see eye to eye. That means that the job of coordinating the program is like herding cats."
Whose Levees?
A fundamental question is: Who owns the levees and who is responsible for maintaining and upgrading them? Schmutte of DWR responded, "The state is not directly responsible for the levees in the delta. Each private reclamation district has that responsibility."
There are scores of these districts. They are made up of local farmers and land owners on the islands. DWR works with them in the Levee Subvention Program to provide funding through a reimbursable program with matching funds permitting them to do levee maintenance. DWR also has a Special Projects Program that provides direct funding to a host of levee projects that are deemed to support the agency’s primary mission of protecting the state’s water supplies.
Chris Neudeck, principal of KSN Engineers in Stockton, works directly with the reclamation districts. He stressed that the districts are "the first level of response" when it comes to the levees. "Since the mid 1980s, there have probably been less than a dozen levee failures, largely because of the infusion of money into the delta through the state’s Levee Subvention Program. The amount of that money spent on local districts is about $6 million per year. We have done very well with it and have probably avoided hundreds of millions of dollars in damage."
In addition, "The flood events of 1980 and 1982 awakened the delta community on the need for daily inspections by the personnel of the reclamation districts, and today that daily inspection is occurring on probably 90% of the islands … We also have an aggressive program to eradicate rodents, but it is never aggressive enough, since they can do tremendous damage."
Finally, A Risk Management Study and Possible Solutions
Professor Mount concluded his dire predictions about the delta with a word of hope, "The good news is that DWR has begun a two-year intensive study of the problems of the delta and what the options are."
According to Schmutte, "The risk analysis currently being conducted by DWR is to quantify the risks and the probability of levee failures and their consequences. We haven’t done a comparison of the probability of risks to the islands to be able to rank them, and that is a part of what we want to do in the risk study that we are embarking on."
"In the delta, you can have levee failures any time, any season, but the consequences change dramatically with the season. The study is very significant because nobody has any figures to go on. The study will say not only what the risks are, but what possible solutions are as well. The dangers in the delta are many, including transportation, pipelines, population, and the environment, but the greatest potential damage is to the water supply."
"We need the delta for many reasons; so, we have to figure out how to make it work," Schmutte said. "Obviously, we can’t continue down our current path." Salt-water intrusion barriers should be considered, and there is "bio-accretion" to reverse the subsidence of the islands.
"For the past 15 years, DWR has been advancing the level of understanding of how to reverse the subsidence process in the delta. Peat moss is made up of dead tulies that grow along the waterways and are matted down during the winter. So, we can also grow peat by means placing layer upon layer of tulie mats on the ground. Green waste from urban area could also be added, and rice straw is a big consideration. We have done pilot tests on a few tens of acres, but what remains are larger scale subsidence reversal tests … The solution to the problems of the delta may require a great many things including levee improvements, turning some of the islands into reservoirs, and even abandoning some of the islands."
The Future of the Delta
We asked Steve Veregin, Deputy director of DWR, "How optimistic are you about the future of the delta?" He replied: "Engineering solutions are feasible, but it depends upon how much you want to spend to sustain the delta. The delta is going to be a part of the California water picture for the foreseeable future. We have to decide what society can afford and how to spend our resources in the most meaningful way."
Finally, we find it strange that nobody has yet mentioned the peripheral canal that was originally proposed for the State Water Project many decades ago. It would bypass the delta as the source of problems for the water supply of California by transferring water directly from the Sacramento River around the delta into the state and federal pumping plants in the south.
Veregin commented, "It remains an engineering-wise variable. And now with the costs that we see for maintaining all of those channels, some people may be poised to ask that question again. It will be a very large public decision."
