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Monday, May 16, 2016

CLASSIC FOES JOIN FORCES TO MAKE DELTA LEVEES "BETTER THAN EVER"

By Patricia McBroom

       On a sunny morning in April, civil engineer Dominick Gulli was out checking the levees in a critical area of the Sacramento/San Joaquin delta where fresh water gets diverted to Southern California. The levees had recently been strongly reinforced to guard against seepage, overtopping, and collapse from various stresses including earthquakes. Gulli is out there two or three times a week to check them out, year after year.
Dominick Gulli, engineer for upgrade
of levees to protect EBMUD aqueduct.
       “Uh-oh,” he said, slowing the pickup truck as he noticed a large puddle of water down on the slope. “Oh, well, it's evaporating,” he added, pointing to the drying patches around the puddle. “Must be from the recent rains.”

Keepers of the Levees

Gulli's company, Green Mountain Engineering, is one of three or four local firms who manage this crucial Delta infrastructure, the viability of which is absolutely necessary for the health and welfare of the great majority of Californians. Woodward Island, which we toured that day, is tiny (three square miles) with nine miles of critical levees. If they were to fail, it would jeopardize fresh water delivery to not only most points south of the delta, but to the East Bay of San Francisco as well. That's how connected and complicated the "water pipes" are in this state.  Their security depends on a handful of heroes who live and work in the Delta, carrying on the traditions of generations of levee builders who keep the islands dry. 
Map of California's "water pipes shows EBMUD
aqueduct (center) crossing the Delta. State and
Federal pumping stations (red squares) lead to
California Aqueduct and Delta Mendota Canal (right)
                           Further north of Woodward Island, another local architect/engineer, Gilbert Labrie, is watching a levee along the edge of the San Joaquin River.  It shows signs of slumping and will need to be repaired this summer.

On Watch in the Delta

       And it's not only the engineers who keep their eyes peeled for levee damage. Delta farmers, as well, watch all the time, reporting suspicious activity to their local reclamation districts that employ the engineers. Just seven years ago, island ranchers saved their levee from a crazy impact by an ocean-going ship on the San Joaquin River that could have shut down much of the state's water supply.
       Civil engineer Gilbert Cosio, with MBK Engineering firm in Sacramento, manages the levees in 27 reclamation districts. He's seen enormous improvements in levee reliability since he began this work in 1984. “At that time, we'd have to sandbag many miles of levee at high tide to keep water from going over the top. Some islands would threaten to flood every three years. They didn't because farmers down there would throw on the sandbags,” said Cosio. “Now we've got about a foot of freeboard (above the 100-year flood) almost everywhere.”
         Seven years ago, in 2009, a devastating State report on the condition of Delta levees predicted that, using average probability statistics, there would be about a dozen levee failures by this year.  None has occurred.

Cooperation and Progress

       Unbeknownst to most people who read about California's Delta, levees there have been steadily improving over the past decade. With State bond money, and now – belatedly – money from water contractors, a surge in reconstruction is taking place. Moreover, the work is being carried out by groups who have long been in opposing camps in the battle for fresh water: delta residents, state officials and water contractors.  It is one of the few places where cooperation is actually resulting in tangible, physical improvements.
       “I am confident that levees in the Delta are in better shape than they've ever been,” said state official, Dave Mraz, who heads up the Delta Levee program at the Department of Water Resources. “It's taken a lot of cooperative effort. We (State officials) pay money to pile up the earth out there and provide roads. Then, when the high waters come, local reclamation districts are out there, doing levee patrols, watching for seepage and actively treating them in the middle of a storm. The system still needs that kind of attention from local interests that have a big stake in making sure their levees stand. We rely on that. Even with all the work the State has done, it's a cooperative effort. We provide (some of) the money, but they do the work.”

EBMUD's Million-Dollar Levees

       A major leap forward was taken six years ago when East Bay Municipal Utility District (EBMUD) made an historic decision to come up with millions of new dollars to fortify the levees on Woodward and four other islands that affect its aqueduct. EBMUD's $6 million paid the local share in a $41 million levee improvement program – shares that Delta farmers cannot and should not have to pay to reinforce levees that benefit 1.4 million EBMUD customers.
Tiny Woodward Island's widened crown and broadened base protects two
critical aqueduct systems in California

       The results have been outstanding. In a very short time (compared to the usual slow pace of levee reinforcement), the levees have been raised in height, often doubled at the crown, and greatly broadened at the base with tons of new dirt creating a gentle slope down, instead of a precipitous drop to the bottom.
The cost of doing all this was not cheap. Forty miles of levee improvement on five islands cost $41 million. That's a million dollars a mile, with the State paying 85% of it, and it reveals why levee improvement in the Delta has been so slow – farmers cannot afford the local share, even at 15%. (These levees are on private land and are therefore not maintained by the Federal or State governments.)
       “This is a real success story,” said Eileen White, water operations manager for East Bay MUD. We did this to improve the stability of the levees out there. Knowing their vulnerability to failure, we wanted to protect the integrity of our pipelines,” said White. The retrofit will protect against floods, seepage of water, damage by rodents and other ordinary failures. 

Earthquake Resistance: The Stronger, the Better


       Whether the new work also protects against an earthquake is unknown, partly because levee failure from an earthquake has never occurred in the Delta in historic times. Widening the crest and broadening the base, however, are classic ways of protecting levees against earthquake damage and scenarios for seismic resistance have been tested in the Delta.

       White couldn't say whether the new levees would withstand an earthquake. She said that would depend on how big it was. “Will this buy protection in an 8.0 on the Rodgers Fault (a portion of the Hayward)? I can't tell you that. But it will make them stronger . The more you do, the better. The wider the top, the flatter the slope, the more stable it is. It's like retrofitting a house. You put in sheer walls; then you bolt it down. There's no guarantee in any earthquake, but we've made the levees stronger without a doubt.”
EBMUD's aqueduct takes water across the Delta to 1.4 million people.
       Moreover, the added dirt and stockpiling of rock on the islands makes it much easier to repair a break immediately rather than waiting days for new material to arrive, several authorities noted. “If the land subsides in an earthquake, we can fill it back in quickly,” said Christopher Neudeck, whose Delta company Kjeldsen, Sinnock and Neudeck, provided inspection and management services on the EBMUD project. With new dirt added to the levee, “We just take a tractor and push it back up. We're doing that everywhere all over the Delta, adding these berms,” said Neudeck.

                                                                                        Two for One Protection

So. California's freshwater corridor runs north to south past Woodward
island in two tributaries (Old and Middle River) to the San Joaquin River.
        A disturbing fact about levees in this part of the south/central Delta is that they are actually dikes that hold water back 24 hours a day and the landward side has sunk below sea level by 10 to 20 feet. They are a core infrastructure for water supplies to Southern California, as well as to the S.F. East Bay. The so called “fresh water corridor” – small rivers that carry water to the California aqueduct – runs right past some of the islands recently reinforced. So, in protecting their own pipes, EBMUD also fortified three of some seven to nine islands along the corridor.
       “By improving these levees, we not only protect our own supplies, but we help the 20 million people in Southern California who rely on water to be pumped from the Delta,” said White. It's a win, win. We have protected a lot of important infrastructure in California. It would be really good if other entities out there who benefit would also step forward.”
       Other “entities” in the area include Metropolitan Water District of Southern California, Westlands Water District in the San Joaquin Valley, PG&E, which has transmission lines in the area, Kinder Morgan with its pipes, a state highway and a railroad. Few of these has contributed any money to reinforce Delta levees, although MET and six other water contractors, plus PG&E, are stepping forward with a small amount (totaling less than $500,000 in local share for all; the State is paying 97%) to reinforce Bacon Island, north of Woodward on the corridor, next year. (Bacon is one of the islands recently purchased by MET).

Into the Future with Toe Berms

Bigger levees with stockpiled material (back, center) 
protect the island and aqueduct (distance) 
from being flooded.

        Back on Woodward Island, Gulli pointed out the “toe berms” added to the back sides of the levees. The new sides sloped gently down, at a one to four foot ratio. Many – but not all – of the levees protecting water delivery routes now have these toe berms. (Engineer Cosio estimated that the entire fresh water corridor would be up to the desired Corps of Engineers' standard, PL 84-99, in about five years).
       “We finished this project two or three years ago,” Giulli explained stopping the pickup again to draw a graph. “The crown here was 14 feet; now it's 22 feet wide,” broad enough for two trucks to pass each other. As we prepared to exit the island via ferry, Gulli pointed out the spot where a levee failed on Jones Tract on a sunny day in 2004, possibly due to a rodent burrow. The EBMUD improvements would protect against that sort of calamity and, indeed, no more failures in the Delta have occurred since that date. But it takes constant vigilance.
        In any foreseeable plan for California's water future, these levees play a central role. Even if the State builds two giant 40 feet-in-diameter tunnels deep under the delta to transport water, we will still depend on these structures to protect our fresh water. And the one thing that has not been analyzed in the 20,000 plus pages of environmental reports on the tunnels is the true impact on Delta agriculture and recreation of a ten-year construction project through the middle of the place.

The Importance of Skin in the Game

        In October of last year, an independent science board that works with the Delta Stewardship Council wrote a detailed analysis ( pages 9-17) of what more than 10 years of heavy-duty construction might do to the Delta economy if the tunnel project is approved. Such a project would have “significant adverse effects on the Delta's unique values,” the report said. Effects on the agricultural economy, recreation values and way of life in the Delta would be serious and have not been adequately evaluated, the report said.
       It is possible that such adverse effects could drive out the few thousand people who maintain this crucial water infrastructure, and then, the State would lose something it could not replace –the eyes and energy of people who have skin in the game.



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