Flood baskets will remain into early 2012
Flood protection baskets placed on top of backwater levees in Morgan City and neighboring Siracusaville will remain in place until sometime in the beginning of 2012 when levee improvement projects are expected to begin.
According to Carl Kraemer, president of St. Mary Parish Consolidated Drainage District 2 — which is responsible for the levees — after the city receives its final elevation report from the Federal Emergency Management Agency regarding how high the levees must be raised to meet the federal agency’s standards, then it will begin work to raise the levees so they can be certified as well as remove the baskets.
Currently, the interlocking baskets, filled with sand and used to protect the area from possible backwater flooding as a result of the high water the area received this spring because of the swollen Atchafalaya River, are on all of the backwater levees under the drainage district’s auspice. These include levees from the Burlington-Northern Santa Fe Railroad tracks in Siracusaville to the Walnut Street Canal in Lakeside as well as from the Justa Street levee west to the A&P Canal.
When work begins on the levees, Kraemer said part of the contract awarded will be to remove the baskets.
In addition to raising some of these levees, any other maintenance work on them will be completed, too.
Kraemer said he was unsure at the moment which levees will need to be raised and wouldn’t know until the city received a final elevation report from FEMA.
While the baskets are onsite, Kraemer said city crews are spraying or cutting around the baskets if they become too overgrown with weeds.
As for the elevations, the city has waged an approximately three-year battle with FEMA regarding the appeal of the government agency’s flood maps for the city.
The city’s fight with FEMA began when FEMA announced the city’s backwater levee system needed to be at 10 feet mean sea level rather than the existing, U.S. Army Corps of Engineers-approved 8 feet.
The finding put a damper on plans to develop the city’s first subdivision in more than three decades.
Currently, the base flood elevation is plus-2 feet and as of now, FEMA is asking for a plus-7 foot BFE for property that is protected by the levees in question, which average between 7 and 8 feet.
If the city raises its levee heights by a certain footage, it can keep the same BFEs.
The city is willing to raise its levees, if possible, to a height that allows them to keep their BFEs the same, Morgan City Mayor Tim Matte has said.
The city already has scraped together $12 million from various sources for the levee improvements, some of which the city has always agreed need to be made.
When the accurate base flood elevation is determined, Matte said the city would know how much to raise affected levees and then could determine a total project cost.
Current predictions are that it could be as much as $16 million to comply with acceptable, new FEMA flood elevation maps.
At the beginning of the decade, city officials said Consolidated Gravity Drainage District 2 — which includes all of the city, plus some neighboring areas — did work on the levees to raise them to the level necessary for a projected 100-year flood.
Matte said during the city council’s July monthly meeting that the latest curveball FEMA threw at the city in its fight to protest what it considered flawed data in FEMA’s model runs has been challenging to counteract.
Instead of continuing to fight what could be a costly venture with a dwindling bank account to finance the actions, Matte said the city was content on receiving the heights it needs to raise its levees to keep its base elevation heights the same, if it is financially feasible. Doing so would allow the levees to be certified.
The latest challenge was a wind-induced “tilt” in the water as it moved closer to the shoreline at Lake End Park. The tilt, similar to a tidal wave, reaches as much as 8 feet by the time it arrives at the park, FEMA officials said.
The phenomenon was discovered when Matte asked FEMA to run the three worst hypothetical storm models it has in its arsenal for the area.
To determine the potential 100-year flood scenario for a particular area, FEMA runs 40 storm models through that area to produce the proper base flood elevations for building houses and businesses in Morgan City. Current base flood elevation requirements of +2 feet were instituted in May 1996.
While the worst storms show Lake Palourde levels remain at two or three feet above its normal levels, they show this tilt occurring halfway through the lake, which has a five-mile radius.
It “doesn’t happen,” said Lucien Cutrera, one of the city’s consultants in its appeal. “We know that.”
Still, the city has expended nearly all of the roughly $140,000 it allocated for its FEMA appeal and challenging the tilt could be a costly venture with little benefit.
While flood modeling and wave expert, Dr. Joe Suhayda (one of the city’s consultants in its appeals process), has said wind can drive water during a storm surge event, it is unlikely that it would be to the extent FEMA said, Matte told the city council in July.
The tilt is just one of the factors the city and FEMA have been at odds about when determining what happens with water flow in Lake Palourde, particularly when comparing FEMA’s models of what happened in Hurricane Rita as opposed to what the city documented during the 2005 storm.
While city leaders have argued that the water in Lake Palourde continues to flow north into a vast area during hurricanes and storm surge events, FEMA previously believed that a barrier in Bayou Boeuf kept the water from continuing to flow into the Pierre Part area.
However, earlier this year, FEMA recognized there is no barrier in this area and water did flow north into this vast area encompassing hundreds of square miles to Pierre Part.
That means, city leaders have argued, that water levels in Lake Palourde should be the same as these backwater areas, meaning water levels throughout these areas must be the same.
Suhayda said that when water reaches 2.5 feet in Lake Palourde above its normal levels, there is enough force to push it in these areas north of Morgan City.
According to Suhayda’s calculations, flood protection should be based on an elevation of no more than 5 feet in Lake Palourde under the flood circumstances presented by FEMA.
He said the flattening across that vast basin of waterways once water levels reach 2.5 feet is significant. That, Matte said, makes him believe that waters in Lake Palourde would never reach 6 feet during any of those storms that FEMA is running models for.