Department of Water Resources
A daily compilation for DWR personnel of significant news articles and comment
November 19, 2008
2. Supply –
A New Look at Risk Revives an Old Plan
Engineering News Record
Wildfires: Did low water pressure hinder the fight?
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A New Look at Risk Revives an Old Plan
Engineering News Record – 11/12/08
By Tom Sawyer, with Jonathan Barnes in
A proposal to build a 42-mile long, 400-ft-wide water conveyance canal soundly rejected by
“Not long ago, risk was a dirty word, but things have changed,” says Martin W. McCann Jr., project technical director of the “Sacramento-San Joaquin Delta Risk Management Strategy” study, one of several concurrent studies analyzing water issues in the state. “Now, [risk] is becoming every man’s tool. But it’s a unique expertise. We need to find the balance in how and when to use it.”
McCann, who also is a dam safety expert and an associate professor at
How experts define and plan for risk mitigation on infrastructure facilities is changing in the post-Katrina world. The emergence of new disciplines developed while studying and recovering from the disaster in
At the direction of Gov. Arnold Schwarzenegger (R),
One of the reports recently delivered to Schwarzenegger, that of the Delta Vision Blue Ribbon Task Force, says such a canal could help protect water quality and ecosystems in the delta, and with that, the state’s water supply. The canal would divert some 700,000 acre ft of river water per year around the fragile maze of islands and levees directly into the 400-mile-long California Aqueduct for delivery to
Voters rejected that plan by a 62% to 38% margin in 1982 over objections to its $3.1-billion cost, in 1981 dollars, and over concerns about negative consequences to the delta’s ecology. But in that debate, the risk of a catastrophic failure of the bulk of the state’s water supply was not often mentioned. This time, although cost and environmental concerns still loom large, risk is expected to play a much larger role in the debate.
The Sacramento-San Joaquin Delta is a maze of tributaries, sloughs, wetlands and islands through which drain two of the largest rivers in the state. Seventy-two islands are clustered within the lacework of freshwater channels, and therein lies the problem. The islands were long ago ringed by levees to protect rich peat topsoil, which over time has blown away and subsided, leaving each island nothing but a ring of poorly constructed levee protecting a huge, deep bowl of fertile farmland. Some of the islands are as much as 36 ft below the surface of the water coursing on the levee’s opposite sides.
Lynchpin
The delta also is the source of water for 25 million people in the Bay Area, Central Valley and
The potential for catastrophic disruption of this system from agricultural levee failures, due to flood, earthquakes or simple bad luck, is high, says McCann. Liquefaction of the levees would be likely in a moderately severe earthquake along one of the faults underlying the western side of the delta, which would lead to a rush of saltwater from
Those figures are derived from risk analysis tools. The ability to access empirical data to develop such estimates is an advantage in evaluating risks of such potential disasters, McCann notes. Understanding how to evaluate risk—and how to use the tools to evaluate risk—can lead to better government practices, he says.
In addition to the DRMS study, which focuses on the risks associated with relying on the delta for such a vital water supply, another recently released report on the area addresses scientific questions of maintaining and restoring its ecosystem, while preserving it as a water source. “The State of Bay-Delta Science, 2008,” by the Calfed Science Program, outlines issues critical to the sustainable management of water and the delta, including history, geophysics, water quality and supply, aquatic ecosystems, levees, climate change and policy developments.
But it is the governor’s Delta Vision plan that represents the closest thing to a call to action and a clear precursor to proposing the peripheral canal again, with risk mitigation in the foreground.
It is a message already striking home. “It is a clear-eyed break with the past,” wrote Spreck Rosekrans, a senior analyst with Environmental Defense Fund in
Rosekrans says the task force’s recommendations for a peripheral canal “raise questions from both an environmental and financial perspective,” since a canal would greatly diminish the flow of freshwater into the delta, and that building new dams would not solve the question of where additional water would be distributed. Even though the report is far from perfect, he believes that “ignoring it would put both the delta and
http://enr.construction.com/news/environment/archives/081112a.asp
Wildfires: Did low water pressure hinder the fight?
By Jeff Gottlieb and Tony Barboza
Residents of
In Sylmar, where about 500 mobile homes burned to the ground, fire officials said they were investigating reports of lack of water pressure there. The Los Angeles Department of Water and Power supplies water to the
In both areas, residents and some officials were openly discussing whether the lack of water pressure complicated the already monumental task that firefighters faced.
Fire officials in Sylmar are checking to see if their department had inspected the mobile home park hydrants as required in the last year, said Craig Fry, assistant fire marshal for the Los Angeles Fire Department.
"We would have had a fair shot if the pressure hadn't gone down," said Battalion Chief Fred Mathis, as he sat in his firetruck in the mobile home park Saturday.
A representative of the company that owns the park, Continental Mobile Housing, said he was busy at Oakridge and did not have time to talk.
Farther south, Ken Vecchiarelli, assistant general manager of the Yorba Linda Water District, said its hydrant system was built to fight fires involving a few houses, not a firestorm.
"This was the type of thing any system in any community was not designed for," he said.
At a packed meeting at
"I was told when they [firefighters] got to the top of our street, they turned back because there was no water pressure," said Diane Manista, whose house burned down in the hard-hit neighborhood of Hidden Hills.
"The fire hydrant in front of our house has a bag on it and wasn't even working. It's beyond words."
Water district officials acknowledged a lack of water pressure and were investigating the problem.
Orange County Fire Authority Batallion Chief Kris Concepcion said Manista's neighborhood did go without water in the hydrants, but firefighters were able to overcome the problem with fire tenders that carry water.
"Did it hamper firefighting? Not really," he said.
"Did additional homes burn as a result? That's hard to say."
But in the Vista Bel Aire subdivision of
One man said he had had spent thousands of dollars to buy a pump to increase water flow from his faucets, hoses and shower heads.
And in one neighborhood that was evacuated Saturday, at least 125 homeowners have been battling low water pressure for several years, according to East Lake Village Community Assn. General Manager Susan Janowicz.
"Some people couldn't even take a shower and wash their dishes at the same time," she said.
"They were trying to water their lawns and not all the sprinklers would pop up."
The association last year persuaded the water district to add new pipelines and valves that will increase pressure, she said. But they're still waiting.
Fire captains also spoke about widespread water pressure problems Saturday. Orange County Fire Capt. Bill Lockhart said his crew hooked up to a hydrant on
"It delayed things a bit, but we were able to make it happen," he said.
Dave Rosenberger, a
He questioned what officials had been doing to anticipate the water demands of a wildfire.
"What was their preparedness plan out there?" he asked. "If I was a resident and my house had been destroyed, and I was going to the water board today, I would be a little bit agitated, a little bit troubled."
Lee Macpherson, coordinator of the Fire and Emergency Technology Department at El Camino College, said that when so many hydrants are opened, it's similar to when a family has turned on the dishwasher, the sprinklers and the washing machine and then someone jumps in the shower: Pressure will dwindle.
Lack of water pressure has hindered efforts to extinguish other fires, such as the blaze that tore through two city blocks at the Universal Studios Hollywood back lot in June, destroying the "King Kong" tour and burning movie sets.
When hundreds of homes in
Fry, the assistant
"Open all the hydrants and there's going to be a significant drop in pressure," he said.
Battalion Chief Corey Creasey of the Glendale Fire Department, who was called to the blaze, said that as his five engines were fighting the fire, they heard radio calls that they needed to conserve water.
The water supply stopped around 5 a.m., he said.
"The system isn't designed to take 50 engines," Creasey said.#
http://www.latimes.com/news/local/la-me-wildfire-water-shortage19-2008nov19,0,1885852,full.story
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