Ocean levels could impact Tri-parish levee system

Arguments about sea levels rising could influence plans for how the Morganza-to-the-Gulf system is to proceed. However, local levee leaders contend doing nothing is not the answer.

According to the latest U.S. Department of Interior Geological Survey, determining an absolute response to increasing sea levels and land loss along coastal Louisiana could be behind delays in federal funding for the outer Morganza construction.

“Predicating shoreline retreat and land loss rates [are] critical to planning future coastal zone management strategies and assessing biological impacts due to habitat changes or destruction,” the IGS report said.

The New Orleans-based Gulf Restoration Network blames melting ice caps and glaziers, influenced by global warming, for having have caused sea levels to rise to a degree that international environmental groups predict sea levels to increase between eight inches and 20 inches by the year 2100. Some environmentalist organizations predict higher numbers, while others offer lower expectations.

For agencies planning and building storm surge protection systems, including Morganza to the Gulf, such speculation places their efforts in question as to if what they are doing will be enough.

“Climate changes increase the difficulty of all of our challenges,” Gulf Restoration Network spokesman Dan Farve said. “Rising seas fueled by global warming will make Morganza to the Gulf and other studies less effective. It makes it more difficult to actually build on land.”

With rising levels come worries that the impact of hurricanes would be greater than anticipated with the existing construction of impact reduction systems.

Terrebonne Parish Levee District Executive Director Reggie Dupre said that the global warming and rising sea levels is one theory that has prompted local levee builders to increase construction heights to match federal requirements, while at the same time the U.S. Army Corps of Engineers evaluates its next move.

“This is more of a federal decision since they are responsible for the outer levee,” Dupre said. “Under post-Katrina standards, the corps has to consider relative sea-rise. So it is difficult to plan. The corps is forced to look at extreme circumstances. That’s one of the frustrations we are facing.”

According to original plans, Morganza was targeted for completion in 2035 with an immediate life expectancy to last until 2085. With state and local funding, the parish has started work on the system. However, because of environmental questions, the corps has delayed federal work with a series of internal calls for reviews and continued feasibility research.

To confuse findings, a report released by NASA claims that ocean levels are not on an uncontrollable surge, but are part of a cyclical weather pattern. This report goes so far as to say sea levels have actually dropped during the past year, but warned that pattern cannot last. NASA climate scientist Josh Willis conceded in a NASA report that even with rises and drops there does appear to be a long-term increase of ocean encroachment on land.

Citing the weather phenomenon known as El Nino and La Nina, Willis described alternating ocean levels as being “sea-level whiplash.”

“It is hard to say how bad it could get,” Favre said in regard to increased sea levels combined with sinking land in the Louisiana delta. He went on to admit that no purpose is served by either panicking or ignoring the situation.

“The interim system, combined with the parish system, still makes us more confident for the future,” Dupre said. “It buys us time for the feds to come in and start spending money in Terrebonne Parish.”

Dupre said that concerns of rising sea levels prompted federal levee heights to increase from 14 feet to 15 feet, even as high as 30 feet if conditions warrant such a move.

“On the other side of that coin, when we do a project today and apply for a permit [the federal government] make us account for the impact on today’s marsh,” Dupre said. “But that is already underwater. They get us coming and going.”

The IGS report noted that “coastal planning and decision making has been done, piecemeal if at all, for the nation’s shoreline.”

“We’re heating up the planet,” Willis said. “In the end, that means more sea level rise.”

“We can’t not do anything,” Dupre said regarding interior levee and floodgate construction that began a decade ago and is on its way of becoming protective wall reaching from Lafourche to St. Mary parishes.

Telephone calls to the U.S. Army Corps of Engineers to address sea level concern in relation to delayed Morganza construction were not returned.