Thinking Outside the Levees
Mar 22nd, 2011 | By Terri Sercovich | Category: top story
FEMA Administrator Craig Fugate recently agreed to modify the agency’s flood modeling policy, an innovative idea that originated with modeling to protect Plaquemines Parish. The Federal Emergency Management Agency will no longer use its “without levee” analyses to determine flood risk maps, which in turn should also lower flood insurance rates. FEMA will now take a more specific and scientific approach tailored to each community.
Plaquemines Parish has two sets of levees on each the East and Westbanks of the River—back levee west, Mississippi River levee west, Mississippi River East, back levee east. 100 year protection cannot be achieved due to land constraints—businesses and residents would have to be displaced.
In 2008 Plaquemines Parish President Billy Nungesser partnered with the Corps of Engineers to test effective methods to lower storm surge. The parish employed the Coastal Hydraulics Laboratory (CHL) at the U. S. Army Corps of Engineer’s Engineering Research and Development Center (ERDC) in Vicksburg, Mississippi to use computer models to quantitatively evaluate the benefits of individual and combinations of restoration projects on reducing hurricane waves and surge. Plaquemines was the first parish to engage ERDC in such modeling.
The first step in the modeling was to evaluate current state and federal coastal restoration projects to identify those projects providing flood protection benefits. Of particular importance were projects that could be augmented to increase their flood protection benefits. Next, four separate combinations of new coastal landscape features were evaluated which indicated that storm wave and surge flood protection can be achieved by each type of feature, with differing degrees of cost effectiveness and timeliness.
The results of the evaluation indicated that prior restoration projects provided only limited flood protection benefits. However, several of the new projects were shown to provide a significant reduction in the storm surge over a broad area by as much as 3 to 4 feet.
Facing the difficulties of crafting flood protection with a limited amount of land, Nungesser said he pushed for building forested ridges outside of the back levees on each side of the parish and rebuilding the natural barrier islands which have eroded over time.
“Realizing that these ridges would deliver more bang for our buck—six dollar sediment out of the river versus $50 clay for levees, and businesses and residents wouldn’t need to be displaced—it only makes good common sense, that’s why we devised this plan,” said Nungesser. “It’s cheaper and more efficient. We no longer have enough land to protect Plaquemines Parish inside the levee system, we must go outside. It will be the first time anything other than floodwalls and levees have been used for flood elevation.
“We’re very proud of Administrator Craig Fugate for considering this,” Nungesser continued. “It is a huge step toward saving Louisiana’s Coast and many people may not yet realize the significance. He’s the first one to step up to the plate and realize that we must do something out in the marsh to lower storm surge to adequately protect coastal Louisiana. We first met with Nancy Ward, the acting FEMA director, and she was very excited about our plan. And now this shows that Administrator Fugate is not afraid to think outside the box, or levees in this case. We applaud his efforts to help us save Coastal Louisiana.
“I also want to recognize Michael Hunnicutt, our local FEMA representative who helped us develop our plan on a local level,” said Nungesser. “Too often local representatives are not credited with their efforts to make positive change on the local level. We want to thank Mr. Honeycutt and all FEMA reps, because it shows that anything is possible when working as a team.”
President Nungesser also credited his Coastal Restoration team and the Plaquemines Parish Council for its continued support.
The Plaquemines Parish Coastal Plan combines coastal restoration with hurricane protection features in different phases including taking better advantage of the flood protection benefits that certain coastal landscape features, such as wetlands and barrier islands, can provide in addition to levees.
In June 2008, the Parish completed the plan for lowering the base flood elevations in the Parish. The plan, called the Plaquemines Parish Strategic Implementation Plan, spells out how the parish will develop a systematic and scientific approach to coastal restoration and flood protection for the Parish. The plan was developed by a team of scientists, planners and other coastal experts led by Dr. Joe Suhayda in conjunction with Dr. Sherwood (Woody) Gagliano, C.E.O. of Coastal Environments, Inc.
The first new project to be selected for construction is a forested ridge on the Westbank of the parish near Venice, identified as the Reach B-2 project. The modeling has shown that the Reach B-2 project will lower storm wave heights at the levees by several feet.
To expedite the construction of such projects, the parish is advocating for the amendment of the permitting process to reflect the urgency of situation.
“Our next step is to work closely with Lisa Jackson and the EPA to make sure her recommendation to President Obama in the fall includes expediting the permitting process,” said President Nungesser. “It takes many years to get a permit under the current system. We permitted the berms in 19 days without any harmful environmental impacts. We must expedite the permitting process to save Coastal Louisiana. This will be our next challenge, but it makes it much easier knowing we have a good team of people working together to achieve that goal.”
Plaquemines Parish house major industries that help power the entire United States, plus a major military base, the Naval Air Station-Joint Reserve Base. The Parish contributes 25 percent of Louisiana’s Mineral Revenues ($240 million in Severance & Royalty Revenues/Year); 23 percent of Louisiana’s oil production; 10 percent of Louisiana’s natural gas production; 35 percent of the annual value of Louisiana’s shrimp, crab and oyster catch; contains the largest two coal terminals in the United States; 62 percent of Louisiana’s citrus industry (acreage and sales); Breton National Wildlife Refuge; Delta National Wildlife Refuge; and Pass-a-Loutre Wildlife Management Area.


[...] Thinking Outside the Levees [...]
There is a discrepancy between what is written in this article and what I read in the Corps report. The article refers to a forested area adjacent to a levee reducing storm surge up to 4 feet. Corps report says that a mature forested area would reduce up to 4 feet of wave height not 4 foot of storm surge. So if a 15 foot surge is coming with a 3 foot wave on it, Plaquemines will still get a 15 foot storm surge. Storm surge is our primary enemy during a hurricane not wave heights. Other factor to realize is that it will take 30 years to grow a mature forest and that forested area will require fresh or minimally brackish water to survive. Not likely that forested area can survive as far south as is being planned at this time given salinities in the area.