Link to site: Matt Scallan, River Parishes bureau, April 01, 2006

Return to: watercenter.org sciencefaircenter.com watercenter.net

Highlights:
- progressively raise water rates for the biggest users, was one of seven options to pay for a proposed $25 million expansion project
- proposal would raise the rate for using 1,000 gallons of water from $2.22 to $4 for customers who use between 6,000 and 10,000 gallons per month and $4.30 for usage of more than 10,000 gallons per month. The first 6,000 gallons of water would remain at the current rate for all users.
- The proposed expansion would involve linking the east and west bank water plants, adding 6 million gallons per day of drinking water capacity on the east bank water plant, and 3 million gallons per day of capacity to the west bank plant, as well as building a new west bank storage tank.


The proposed water rate increase that the St. Charles Parish Council will consider on May 1 is designed to tread lightly on most water users and avoids funding mechanisms that would require voter approval.

The measure, which would progressively raise water rates for the biggest users, was one of seven options to pay for a proposed $25 million expansion project that engineer Rick Shread presented to the council at a special meeting Thursday.

The other measures would have either required the parish to seek voter approval for increased property taxes or required small water users to pay more.

The plan that the council is considering will be introduced in ordinance form at Monday's council meeting. It won't come to a vote until the council's May 1 meeting. That proposal would raise the rate for using 1,000 gallons of water from $2.22 to $4 for customers who use between 6,000 and 10,000 gallons per month and $4.30 for usage of more than 10,000 gallons per month. The first 6,000 gallons of water would remain at the current rate for all users.

Adoption of the plan would mean that 62 percent of the parish's 17,549 residential users would see no rate increase, according to Shread's firm, Shread-Kuyrkendall and Associates.

Currently, all users pay the $2.22 rate regardless of how much water they use, plus a $4-per-month service fee.

The proposed expansion would involve linking the east and west bank water plants, adding 6 million gallons per day of drinking water capacity on the east bank water plant, and 3 million gallons per day of capacity to the west bank plant, as well as building a new west bank storage tank.

To pay for the expansion, the system must generate about $3 million a year for the next 25 years, either by raising user fees or through property taxes.

Councilman Clayton "Snookie" Faucheux said St. Charles is the only parish in Louisiana where the water system isn't subsidized by property taxes. The parish levied a property tax until the east and west bank water systems merged in the late 1980s. Parish officials say the taxes went off the books in the mid-1990s, and the parish switched to a fee-based system, partly because of industry requests.

As they would under most of the options presented at Thursday's meeting, businesses would bear the brunt of the rate increase through taxes or higher user rates.

Lily Galland, chairwoman of St. Charles Industrial Council, said she could not comment on the specifics of the council plan, but said the parish's industrial taxpayers are willing to help.

"We want to work with the parish to ensure that the infrastructure meets the needs of its citizens," she said.

Ron Guillory, spokesman for the Valero St. Charles Parish Refinery in Norco, said the company won't comment on the proposal until it has a chance to study it, but noted that the refinery voluntarily reduced its water usage from about 60 million gallons per month to about 20 million after water supplies got tight after Hurricane Katrina.

The east bank system has been stretched to its production capacity and the main production unit cannot be turned off for needed repairs without causing a critical water shortage, parish officials say. Two smaller units produce water at a combined maximum rate of 3 million gallons per day, but their actual daily capacity is less.

Waterworks director Robert Brou said the main east bank unit could suffer a catastrophic failure at any time, leaving the east bank without enough water to meet its needs.

In addition, the west bank water system will begin facing its own capacity issues in the next few years as an expected 5,000 new homes are built in existing subdivisions.

"We're supposed to be the silent service, but people don't realize how much technology goes into a glass of water," Brou said.

Parish President Albert Laque's administration also proposes linking the two plants with a connection across the Mississippi River, building a million-gallon water storage tank on the west bank, and expanding that plant's daily capacity from 9 million gallons to 12 million gallons.

One of the options that Shread presented to the council would have involved asking voters to approve a 3.76-mill property tax, possibly in a July 15 referendum.

But Parish Council Chairman Brian Fabre said passing a property tax is no sure thing.

"It used to be that if you proposed a tax, everybody would vote for it because it would be on industry's back, but not since everybody got reappraised," he said, referring to the dramatic rise in property value that led to an increase in residential tax bills in 2004.

Shread noted that calling a referendum would be time-consuming and possibly could fail in a parishwide vote and delay the resolution to the most serious problem.

Other options that were considered include:

-- Raising rates to $3.45 per 1,000 gallons, which would mean a $7.38 monthly increase to a customer using 6,000 gallons.

-- Raising the monthly service fee from $4 to $16.77, an increase of $12.77 per month to all existing customers.

-- Raising the monthly service fee from $4 to $5 and the rate to $3.30 per 1,000 gallons. This would cost the user of 6,000 gallons of water an extra $7.48 per month.

-- Splitting the revenue stream by raising water rates to $2.84 per 1,000 gallons and levying a 1.96-mill property tax. This would raise the bill of a 6,000-gallon user by $3.72 per month, plus the property tax increase, which would total $9.80 per year for the owner of a homestead-exempt home assessed at $125,000. A business assessed at $500,000 would pay an additional $147 a year in property taxes.

. . . . . . .

Matt Scallan may be reached at mscallan@timespicayune.com or (985) 652-0953

Link to site: Regional Information - Hurricane Katrina

Return to: watercenter.org sciencefaircenter.com watercenter.net

Highlights:
- These pages cover water-related issues associated with Hurricane Katrina (2005) and other hurricanes.


Hurricane Health and Safety
DHHS. Centers for Disease Control and Prevention.
Provides information on drinking water safety, sanitation, and hygiene following hurricanes and other natural disasters.

Hurricane Response 2005
Environmental Protection Agency.
Provides information on drinking water safety, flood waters, EPA response activities and related issues.

Hurricanes
Louisiana State University. Extension Disaster Education Network.
Covers a range of topics including flood recovery, locating safe drinking water and emergency sanitation.
Hurricane Katrina
Librarians' Index to the Internet.
Contains sections on environmental factors, flood cleanup, flood control and levee management, maps and images and more.
Louisiana Department of Environmental Quality
Louisiana Department of Environmental Quality.
Provides information from the state environmental agency. See also Mississippi Department of Environmental Quality and Mississippi Department of Health for drinking water information.
Hurricane Season 2005: Katrina
National Aeronautics and Space Administration.
Has satellite images, before, during and after Hurricane Katrina.
Hurricanes: Links to Health Information
DHHS. National Library of Medicine.
Provides links to environmental health and toxicology information.

Hurricane Katrina Images
DOC. National Oceanic and Atmospheric Administration.
Provides images "of the Gulf coast of Louisiana, Mississippi and Alabama after Hurricane Katrina made landfall." NOAA's National Climatic Data Center has created a Summary of Hurricane Katrina page with sections on storm meteorology and background; rain, wind and pressure; and impacts of the storm.
U.S. Army Corps of Engineers
DOD. United States Army.
Provides many links to information about Corps activities in the hurricane-affected area.

Hurricane Katrina Special Feature
DOI. United States Geological Survey.
Contains information from the agency, including pictures of New Orleans and the coast before and after the hurricane.

Link to site: Bob Marshall, Staff writer, March 17, 2006

Return to: watercenter.org sciencefaircenter.com watercenter.net

Highlights:
- The combination of forces that brought the structure down was its finding that one of the main triggers for that failure -- extremely low soil strengths under the toe of the levee -- would have been detected had the design team done soil borings in that area
- "The factor of safety would have been (low enough) to where they would have changed the design,"
- The task force said rising water pushed the wall away from the canal, eventually creating a crack, separating the wall from the canal-side levee. Water pressure building inside the crack began pushing down on soil layers under the wall, which required support from the levee on the land side of the canal and the soils adjacent to it. The weak soils beneath the toe of the levee couldn't stand up to the rising pressure and began slipping, bringing the levee and the floodwall down.


The key to learning why the 17th Street Canal floodwall failed during Hurricane Katrina may lie more in what designers didn't do than in what they could have foreseen, experts now say.

Lost in the controversy swirling around a government panel's comment last week that the designers of the floodwall could not have anticipated the combination of forces that brought the structure down was its finding that one of the main triggers for that failure -- extremely low soil strengths under the toe of the levee -- would have been detected had the design team done soil borings in that area, an official with the Army Corps of Engineers said Thursday.

Had the weakness at the toe of the levee been included in the analysis system used by the project designers, "The factor of safety would have been (low enough) to where they would have changed the design," said Reed Mosher, a researcher at the corps' Engineering Research and Development Center in Vicksburg, Miss., and a member of the corps-sponsored Interagency Performance Evaluation Task Force that is investigating the failures. The options considered probably would have included a T-wall, or a much larger levee, he said.

The task force said rising water pushed the wall away from the canal, eventually creating a crack, separating the wall from the canal-side levee. Water pressure building inside the crack began pushing down on soil layers under the wall, which required support from the levee on the land side of the canal and the soils adjacent to it. The weak soils beneath the toe of the levee couldn't stand up to the rising pressure and began slipping, bringing the levee and the floodwall down.

Review team members said the designers did "few if any" soil borings at the toe of the levee, a finding John Greishaber, acting chief of the engineering division at the corps' New Orleans district, said was not normal. He said his office normally required designers to take borings at the center line as well as at the toe of levees.

"This is the preferred method," he said. "There are items when this is not done. You have to get into specifics (for each case) as to why it is not."

Greishaber said that when borings aren't made, engineers can estimate the soil strengths at the toe of a levee.

Engineers use a standard formula for estimating the soil strengths at the toe based on the known strength of soils at the center line of the levee, where the soil strengths are highest. That means soil borings at the toe usually aren't necessary unless the center line values are below a certain threshold, task force members said.

And that is where the designers made obvious mistakes, said J. David Rogers, a professor at the University of Missouri-Rolla who is a leading expert on levee failures and a member of a National Science Foundation investigation into the disaster.

"Looking at their calculations on the slope stability analysis, they used the same high figure from the center of the levee and projected it out to the toe, without any diminution in value," Rogers said. "That was one of the first things we picked up when we started working on this.

"When we tried to find out what factor they used for diminution with increasing distance from the toe, it didn't appear they used any. They were using maximum strength all the way to the toe. That's the part everyone will take issue with."

More surprising, Rogers said, is the fact that obvious mistake was missed by the corps in New Orleans, as well as its superiors in Vicksburg.

"I can't explain how this went through," he said.

Making waves

Although the quality of the engineering done by local firms and reviewed by the corps has been the focus of scrutiny since shortly after the walls collapsed, it was pushed from the headlines last week when the task force released an interim report identifying how the walls collapsed and saying the combination of forces responsible could not have been anticipated by the project designers. That provoked criticism from independent investigators.

But this week Ed Link, project director for the task force, said his panel's statements had been misconstrued by the media.

"Our position on this is that, very simply, whoever did the design just did not consider this particular mechanism," said Link, a University of Maryland senior fellow who is head of the corps-sponsored Interagency Performance Evaluation Task Force. "We, IPET, made no value judgment whether it should have been considered or could have been considered.

"If that was inferred by our comments, it was inaccurate."

Link added that the corps has made no attempt to interfere or steer the investigation by the panel, which lists more than 150 members from academia, private industry and other state and federal agencies.

"The only pressure the corps has put on us is to find out what has happened and put it in the public domain," he said. "I'm telling you as an engineer, as a professional, I would not work in this environment if I felt there was anything political or adverse pressure on what we are doing."

The executive summary of the task force report, which Link said he wrote without input from the corps, said "this failure mechanism was not anticipated by the design criteria used."

When task force panelists and corps engineers were asked if that meant the design systems used by the engineers of the day could not have foreseen this type of failure, they answered "yes."

Link said that while the individual components of the failure are well documented as concerns for engineers doing stability analysis of levees and floodwalls, the combination of those factors coming together at the same time is not. He also said methods of analysis used by engineers at the time would not have included all those factors in testing a design for stability.

Point of contention

Task force panelists at the press conference also said a "search of the literature" turned up no examples of this specific failure mechanism.

Those claims were quickly challenged by members of the engineering community. Most notably Ray Seed and Bob Bea, University of California-Berkeley professors and members of the National Science Foundation team investigating the levee failures, issued a response calling the task force statements "unfortunate" and inaccurate. They called attention to a 1986 report done by the corps, known as the E-99 report, that showed the separation -- "tension cracking" -- of the wall as well as the build-up of high pressure at the base of the floodwall after the cracking.

They also cited two 1997 papers published in an industry journal analyzing the 1986 test. One of papers' authors was Mosher, who is a member of the task force.

Link said Thursday that his reference to the "literature" meant a review of the corps engineering manuals, which design teams are required to use.

"We were looking at the design criteria to see if there was a process like this described in the corps' design manuals that (the design team) missed," he said. "We didn't see anything that described this mechanism, that would have alerted (the design team) to look for this when doing their analysis."

Link and Mosher disagreed with Bea and Seed's analysis of the importance of the 1986 study. Mosher, who analyzed the E-99 report, said it was not designed to look at levee stability, but at how much a sheet pile "moved at the top as water increased."

The fact that the test also showed there was evidence of tension cracking and high pressure at the toe of the wall was not given much attention at the time, Mosher said, "because the study was not designed to look at the stability of the levee." He also said the evidence of cracking and increased pressure was minimal.

Rethinking strategies

Mosher said Katrina has made the report important today.

"When I go back now and look at E-99 knowing the other pieces of information about the 17th Street failure, I can make a better interpretation of what's in E-99," he said. "Now I can say I understand how all this relates."

Mosher and Link said the lessons learned from the investigation already are being put to work.

"We're going back and doing borings at the toes of the levees in the system anywhere we think this failure mechanism might be present," he said. "We're already doing re-evaluations of the stability analysis done by the (original design teams).

"Now that we know what to look for, we're out there looking for it."

. . . . . . .

Bob Marshall can be reached at rmarshall@timespicayune.com or (504) 826-3539.

Link to site: Bob Marshall, Staff writer, March 11, 2006

Return to: watercenter.org sciencefaircenter.com watercenter.net

Highlights:
- Unique combination of stresses that engineers could not have predicted caused the 17th Street Canal floodwall to fail and flood thousands of homes and businesses during Hurricane Katrina, according to an interim report of the task force investigating the disaster for the Army Corps of Engineers.
- Evidence points to forces that came together in a combination unique to the science and thus could not have been anticipated by the system's design teams.
- Interagency task force members said experiments with sophisticated computer models show the 17th Street Canal floodwall came down in a four-step process:

A unique combination of stresses that engineers could not have predicted caused the 17th Street Canal floodwall to fail and flood thousands of homes and businesses during Hurricane Katrina, according to an interim report of the task force investigating the disaster for the Army Corps of Engineers.

The report also points to soil subsidence that left floodwalls and levees lower than design specifications as contributing to the other failures and breaches that helped flood 80 percent of New Orleans and killed more than 1,100 residents in August.

Although independent analysts have blamed the 17th Street Canal failure on faulty engineering, including flawed soil investigations by local firms, the Interagency Performance Evaluation Task Force, composed of experts from academia and industry as well as state and federal agencies, said evidence points to forces that came together in a combination unique to the science and thus could not have been anticipated by the system's design teams.

"I would say it's certainly going to come as a surprise to many people, if not most people," said Ed Link, University of Maryland professor and task force project director.

The group said the causes of the London Avenue canal floodwall collapses are not yet known and emphasized that its findings are preliminary.

Bob Bea, a University of California professor who is part of a National Science Foundation investigation into the failures, said the task force's explanation of the 17th Street Canal breach is lacking.

"It's our jobs as engineers to anticipate the failure points, and when that doesn't happen, breakdowns like this occur," Bea said, emphasizing that he is speaking only for himself and not the NSF team. "The corps has a documented history where they say, 'We couldn't have anticipated this, therefore it was an act of God.'

"An experienced engineer knows he can't accept that."

Four steps to hell

Interagency task force members said experiments with sophisticated computer models show the 17th Street Canal floodwall came down in a four-step process:

-- As water in the canal rose to 10 feet -- an unprecedented but not unplanned height -- the pressure from the water and wind-driven waves in the canal began to push, or deflect, the concrete floodwall and its subsurface supporting steel sheet piling away from the canal and toward Lakeview.

-- The deflection created space between the wall and the levee on the canal side.

-- Such flexing is expected by designers, as is a small opening between the wall and the levee. But what happened in this case, and was not expected, was the separation extended the entire length of the sheetpile wall to 17.5 feet below sea level. Water rushed into this opening quickly, creating a channel separating the floodwall from the levee on the inside of the canal and allowing high water pressure to travel directly down to the soil layers beneath the wall.

-- The final blow came when a layer of clay about 15 feet below sea level that extended beyond the toe of the levee began slipping toward Lakeview, causing the levee to collapse and the wall with it.

'Failure mechanism'

The fatal flaw in the weak soils beneath the structure was not the now-notorious layer of peat widely cited by independent analysts for months, the task force said. In fact, the failure surface, as engineers call it, did not occur under the levee or canal, but at a level beneath the toe of the levee and in the yards of homes adjacent to the canal.

Link said task force tests showed the soil-strength estimates done by local firm Eustis Engineering when the walls were built proved to be more conservative than actual results. Further, he said there was no method of testing the plans for a combination of forces that caused the collapse -- called the "failure mechanism" by engineers.

"We've searched the literature and found nothing that resembles this," he said. "I'm not saying nothing exists, but so far we haven't found it."

There was disagreement on that point.

Bea said a 1986 corps study showed such separations could occur.

"That report was done by the Vicksburg (Miss.) research station for the New Orleans District, but there's no evidence it ever made its way to the (engineering) firms doing the work," said Bea, who added that a full discussion of the report would be in the National Science Foundation study to be published next month.

Corps officials acknowledged the report, titled "E-99 Sheet Pile Wall Field Load Test Report," but disputed Bea's interpretation.

Neither the interagency task force nor the corps dismissed the long-standing criticism that sheet pilings should have been driven at least to the bottom of the canals -- a standard engineering practice -- rather than stopped at 17 feet. While they agreed deeper pilings generally make stronger walls, they have yet to run simulations to determine whether deeper pilings would have prevented this collapse given the other conditions now known.

Sinking floodwalls

Soil subsidence levels in a region that was largely marsh and swamp fewer than 100 years ago is well known, but the rate of sinkage, which left many structures below the heights built to guard against storm surges, apparently took the panel by surprise. For example, the Industrial Canal floodwall that was built to 15 feet actually measured just above 12 feet when Katrina hit, a loss of 2.7 feet.

Task force teams "documented that many sections of the levees and floodwalls were substantially below their original design elevations, an effective loss in protection," the report said.

Corps officials said the Bush administration has budgeted almost $3 billion to repair and restore all levees and floodwalls in the region up to design heights during the next two years.

Louisiana State University professor Ivor van Heerden, a member of the state team investigating the failures, said he was not surprised by the report and generally agreed with its findings. He said the corps started using updated elevation data only five years ago, even though the state had been urging a change for years.

"So the fact that the corps have found some levees lower than they should be reflects local subsidence but also that they built them lower than they should be because they would not update their datum," van Heerden commented by e-mail. "It is cheaper to make a wall 12.8 feet tall rather than one 14 feet tall!"

Further, van Heerden wrote, "whether the fail plane (on the 17th Street Canal) was in peat or clay is really academic. The structure underwent catastrophic structure failure, the same for the two breaches on the London Avenue Canal."

Hassan Mashriqui, an engineer and storm modeler at the LSU Hurricane Center, said he would be cautious about estimates of wave forces inside the 17th Street Canal because his findings show that a huge pile of debris that stacked up against the Old Hammond Highway bridge across the canal probably blocked much of that force.
Bob Marshall can be reached at rmarshall@timespicayune.com or (504) 826-3539.