Federal officials got a police escort down La. 1 in 2012, on their way to help identify underwater debris that knocked out critical infrastructure supply line. Credit: Courtesy of National Ocean Service Website

As the state prepares a required five-year update to its long-term Coastal Master Plan, new research has revived three questions that some experts have had for years. The Lens is looking at each question individually this week. Today:

Is it worth investing $90 billion in wetlands that might be gone 40 years later?

The logic behind Louisiana’s 50-year vision for coastal survival has always been the claim it could build more wetlands than the Gulf could consume during that time period.

But with projections now showing sea level rising dramatically beyond that 50-year window in the Coastal Master Plan this question is increasingly being asked: Is it wise to bet your future on wetlands that may survive the Gulf for only 30 years after they are built – or should that money be invested in building a longer-term future?

As with most questions about a plan facing so many uncontrollable variables, the answer to this one isn’t simple.

And it’s more than a $64,000 question. What started out as a $50 billion plan is now projected to cost at least $92 billion.

Advocates for the longer-term view contend that abandoning the lower coast and moving communities and businesses will be painful in the short run, but provides more certainty the state will have a viable coastline in the next century.

Those favoring the 50-year time frame point to the many uncertainties surrounding the long-term predictions of sea level rise: What if after all the social and economic disruption, the worst-case never happens?

But they also make this point: The projects may well pay for themselves even if they have a life of only 30 to 40 years beyond 2061.

“There is value to the state both in fisheries production and attenuated storm surge that has to be counted during the decades those new wetlands are in service,” said Kyle Graham, former executive director of the state’s Coastal Protection and Restoration Authority.

“The general order of magnitude of the economic assets and activities at risk from land loss do provide strong support for large-scale spending on the order of tens of billions of dollars.”LSU researcher Stephen Barnes

“And people seem to assume these projects will just stop at 2061. No – they will be continuing to operate, building wetlands and providing economic benefits that can be measured in the future.”

Agency officials said there has been no cost-benefit analysis done on the economic return of the wetlands projected to be built through 2061. However a study on the losses to the state if nothing is done to stop the current rates of land loss – which would result in the flooding of most of the southern corner of the state by 2060 – showed an economic hit of $133 billion over the next 50 years.

Conducted by LSU and the RAND Corporation, the Economic Evaluation of Coastal Land Loss in Louisiana tabulated the toll 25 and 50 years into the future if nothing is done. The report relied on the two land-loss scenarios in the 2012 master plan that used 10 inches of relative sea-level rise for a moderate case, and 17 inches for the less optimistic. The master plan estimates for project accomplishments are based on the moderate scenario.

The increased rates of sea level rise and subsidence measured and predicted since then have the 2017 plan using a range of 16.8 inches on the moderate side and 25.2 on the high side.

The report looked at costs directly related to permanent land loss, as well as storm damage losses, which are expected to increase as the wetlands that once buffered development disappear.

Among its findings:

  •       $2.1 billion to $3.5 billion in one-time costs to replace commercial buildings and industrial infrastructure.
  •       $5.8 billion to $7.4 billion annually in lost economic activity. It estimates between 800 and 1,200 businesses with be affected, endangering $2.4 billion to $3.1 billion in annual sales and payrolls of $400 million to $575 million.
  •        $5 billion to $51 billion in total lost economic output due to increased storm damage.
  •       $10 billion to $133 billion in increasing storm damage to mostly commercial buildings and infrastructure.

LSU researcher Stephen Barnes, co-author of the report, said to properly estimate the economic benefit of the wetlands that will be built by the current plan would require a different study, but the figures from the future without action provide a good clue.

“The general order of magnitude of the economic assets and activities at risk from land loss do provide strong support for large-scale spending on the order of tens of billions of dollars,” he said.

Yet there is another economic question about Louisiana’s coastal plans that can’t be answered by the cost-benefit look at the 50-year plan: Where will it turn for the funding to survive post-2061 if seas rise as dramatically as some researchers now forecast?

Graham said the real gamble would be trying to bet on what 2100 would look like.

“We can spend a tremendous amount of effort and money trying to get our best estimate of what the future holds at 2100, but we’ll have very little confidence in what we come up with,” he said. “It’s like predicting the weather: The further out you get the less likely you are to be accurate. It gets crazy.”

Rob Nairn is an engineer on one of the winning teams in the Changing Course Design Competition that recommended abandoning the lower river communities and moving diversions much further north. He believes what the state is building with the current plan “eventually will all be under water.”

But he doesn’t believe the plan is a mistake or a waste of money.

“If you are not going to retreat, then there is probably a cost-benefit to fighting it,” he said. “It’s going to be a battle, but it’s a great start, and they will be having some positive impact.

“But eventually it will all be under water, and then they will have to retreat and look at these other ideas.”

This story is the last part of a series looking at three questions facing state officials as they update the Coastal Master Plan. The first story is here, with links to the rest at the bottom of that story.

Bob Marshall

From 2013 to 2017, Bob Marshall covered environmental issues for The Lens, with a special focus on coastal restoration and wetlands. While at The Times-Picayune, his work chronicling the people, stories...