Department of Water Resources
A daily compilation of significant news articles and comment
August 31, 2007
5. Agencies, Programs, People
SAN JOAQUIN
Levees' strength under scrutiny; FEMA revisiting previously accredited barriers after Katrina - Fresno Bee
Ring of levees appears sound; No major problems in early report on Marysville levee - Marysville Appeal Democrat
LEVEE SURVEYING:
DWR to Conduct Aerial Levee Surveys; Helicopter flights will evaluate integrity of flood control levees - News Release, Department of Water Resources
SAN JOAQUIN
Levees' strength under scrutiny; FEMA revisiting previously accredited barriers after Katrina
By Inga Miller, staff writer
Among the levees they're looking at is one separating the
Federal insurance maps show the levee holding against a 100-year flood -- the type of flood with a 1% chance of happening in any year. But in an effort hastened by catastrophic levee failures in
FEMA is redrawing its flood maps, and each levee previously accredited to provide 100-year protection has to be approved again. If it isn't, areas currently shown as protected will be redrawn as at risk -- which could hit developers and home buyers in the pocketbook with steeper insurance premiums and tighter building restrictions.
"This [levee] is obviously of concern because of new development there and the future community," said Eric Simmons, an engineer with FEMA.
Because the levee shows protection from a 1% flood chance, the area is considered at moderate risk of flooding, and developers can build houses below the flood level. Homeowners aren't required to have flood insurance.
The review is generating criticism among developers and local officials who say the levee meets standards in place when it was accredited in 1990. Changing the rules now, they say, is unfair. And there has been no word on how districts are supposed to pay for repairs, said Dante Nomellini, attorney for Reclamation District 17, which owns the levee.
The levee held during the 1997 flood. The New Year's flood that year broke a nearby levee on
"You shouldn't disqualify someone who met the certification back in 1990," Nomellini said. "They approved it again after the 1997 flood when repair work was done, and the levee was improved. So what is the basis for changing the map status? There is no maintenance deficiency." #
http://www.fresnobee.com/263/story/126104.html
Ring of levees appears sound; No major problems in early report on Marysville levee
Marysville Appeal Democrat – 8/31/07
By John Dickey, staff writer
While studies are continuing, an investigation of Marysville levees has turned up no major problems yet, a team of engineers told the Marysville Levee Commission.
Engineers gave a preliminary geotechnical evaluation report Thursday to the commission. They noted that the studies have to be finished before making any judgments.
“Based on this information we have right now, we don’t find any problems yet, but we’ll hold off until we get the additional investigation completed to do the analysis,” said Claudio Avila, engineering geologist with the state Department of Water Resources, after the meeting.
At least some work is likely to be needed to strengthen Marysville’s levees against a 1-in-200 flood, one engineer noted.
Engineers and geologists are looking at the city’s entire levee system, including the 7.6-mile ring levee that protects Marysville from the Feather and Yuba rivers and a 3.9-mile spur levee that runs out to
The Marysville levee investigation that started in November 2006 is part of a $35 million Department of Water Resources project that is evaluating 350 miles of
Engineers will looking at materials taken from levee borings, historical information, and data gathered from electronic devices implanted in the levees. So far, 61 borings have been taken every 1,000 feet.
Thursday’s briefing noted only two historical trouble spots for seepage – one near Binney Junction, and one near the retail complex that houses Longs Drug Store. In both cases, water from boils flowed clear, which is a good sign because it shows that dirt is not being moved from inside or underneath the levee. That could undermine the embankment and cause it to fail.
The past 10 months have been spent searching for evidence of seepage, which is the flow of water underneath or through the levee. Engineers are also checking whether the levees are stable, and are even trying to determine whether the embankments can hold up to an earthquake. Violent shaking can liquefy some types of soils, causing a levee to collapse.
Next month, crews will start another round of work including core drilling into levee toe areas, and a closer look at spots that need more study before any engineering judgments can be made. Drillings will be augmented with electromagnetic surveys made by helicopter.
Plans are to wrap up the work by March 2008, with a report issued to the DWR.
Some of the officials at Thursday’s meeting found the lack of bad news encouraging even though it was preliminary.
“That’s good to hear you’re not running into areas,” said Marysville Levee Commissioner Pat Ajuria.
http://www.appeal-democrat.com/news/levee_53376___article.html/marysville_levees.html
LEVEE SURVEYING:
DWR to Conduct Aerial Levee Surveys; Helicopter flights will evaluate integrity of flood control levees
News Release, Department of Water Resources – 8/30/07
Contact: Elizabeth Scott, DWR Public Information Officer, (916) 835-5344 or mescott@water.ca.gov
The helicopter will carry an aerial sensor suspended about 100 feet above the ground. The sensor technology, airborne electromagnetics, is safely used throughout the world in mineral exploration and the evaluation of land features and natural resources. A photograph of the helicopter and the sensor is available at: http://www.levees.water.ca.gov/evaluation/images/helicop_sensor.jpg
DWR will hold two media opportunities for this survey effort. There will be a ground demonstration of the equipment at 9:00 a.m. on Wednesday, September 5 at the
The flights, which are part of the state’s commitment to improving flood safety, are expected to continue into early October. The effort is being funded through Propositions 84 and 1E, which were approved by
Flights will take place along the Feather River, Bear River,
When finalized, flight information and schedules will be posted and updated daily online at www.levees.water.ca.gov.
Media Events
Ground Demonstration
When: 9:00 a.m., Wednesday, Sept. 5, 2007
Where:
Directions from
Travel north on I-5 to 99 North (Yuba City/Marysville) Travel north to 70. Travel north on 70 to the
Flight Demonstration
When: 9:00 a.m. Thursday, Sept. 6, 2007
Where: DWR Sutter Maintenance Yard (Near
Directions from
Go north on Interstate 5 to the 99/70 (
The Department of Water Resources operates and maintains the State Water Project, provides dam safety and flood control and inspection services, assists local water districts in water management and water conservation planning, and plans for future statewide water needs.
DWR's California Water News is distributed to California Department of Water Resources management and staff, for information purposes, by the DWR Public Affairs Office. For reader's services, including new subscriptions, temporary cancellations and address changes, please use the online page: http://listhost1.water.ca.gov/mailman/listinfo/water_news. DWR operates and maintains the State Water Project, provides dam safety and flood control and inspection services, assists local water districts in water management and water conservation planning, and plans for future statewide water needs. Inclusion of materials is not to be construed as an endorsement of any programs, projects, or viewpoints by the Department or the State of
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