In a recent letter to the state Coastal Protection and Restoration Authority, the National Marine Fisheries Service expressed many of the same concerns about the planned Myrtle Grove diversion voiced by opponents of the diversions contained in the state master plan for the coast.

The agency raised questions about:

  • The displacement of important species and loss of their habitats as the river water reduces salinity levels in estuaries
  • Research showing pollutants carried by the river could make marshes more susceptible to erosion by storm surges
  • The possibility that the sediment load in the river may not be large enough to produce the results the master plan predicts

The comments were contained in the fisheries service’s response to a request for feedback to help the state prepare for the federal permitting process. The letter is intended to give the coastal authority a head start in responding to issues the fisheries service will bring up in the permitting process for the Mid-Barataria Sediment Diversion (the official name of the Myrtle Grove project) .

This early exchange is part of a cooperative effort between Gulf states and federal agencies to expedite what is expected to be a regulatory logjam for Gulf coastal projects when fines from the Deepwater Horizon disaster finally begin flowing.

David Muth, director of the National Wildlife Federation’s Mississippi River Delta Restoration Program, described the letter from the fisheries service as a “list of chores.”

The Coastal Protection and Restoration Authority “was wise to ask for the rules of the road before getting too far down it,” he said via email. Once the agency completes the checklist, “we are confident that the EIS [environmental impact statement] will reflect that building Mid-Barataria will result in net gains over a future without the diversion.”

The permitting process requires comments from federal agencies responsible for managing public resources in the project area. Agencies with concerns typically ask the applicant to adjust the projects to eliminate or lessen possible impacts, or to outline programs to compensate for the impacts.

Those requests are not binding. The permitting agency, for example the U.S Army Corps of Engineers, can issue the permits over the objections of consulting agencies.

In its review of the diversion, the fisheries service was careful to first state that it supported efforts to stop coastal land loss. It did not say the project should not be built.

But the agency, charged with protecting habitat important to marine species, spent most of its four-page response, dated June 26, listing its concerns, stating the project might:

  • “Displace marine fishery species from currently productive habitats to less supportive habitats”

  • “Reduce marine fishery productivity”

  • “Convert essential fish habitat to areas no longer supportive of some federally managed marine fishery species or their prey items”

  • “Render wetlands impacted by diversions more susceptible to erosion from storms”

  • “Degrade water quality”

  • “Cause socio-economic hardship to those involved in the commercial and recreational fishing industries”

The agency also said reduced estimates of the river’s sediment load, combined with accelerated sea-level rise, means “the 300 square mile estimate of net land change outlined in the Louisiana Master Plan associated with the use of multiple river diversions deserves further scrutiny.”

Because of that concern, the agency “believes it is important for an independent scientific body to evaluate models being used to determine the potential for wetland benefits likely to occur from the MBSD project, as well as the associated risks to EFH (essential fish habitat) and living marine resources.”

Those concerns have been raised by groups opposed to the river diversions, as well as some coastal researchers.

“It mirrors what we’ve been saying,” said George Ricks, a charter boat captain who is president of the Save Louisiana Coalition. That group wants the state to rebuild wetlands by dredging sediment from the river and pumping it into sinking basins rather than the combination of that approach and diversions currently in the master plan.

“It’s point-by-point what we’re saying will happen when they put the river in the marsh.”

The National Wildlife Federation, however, supports using diversions to rebuild the coast. Muth said the letter should have included an acknowledgement “that the Barataria Estuary is not a static landscape, and that it is already undergoing profound negative changes.

“With no action, projections for the future of Essential Fish Habitat in Barataria are poor, with almost all important estuarine marsh likely to disappear in the coming decades. Any project must be evaluated against that scenario, and the short-term trade-offs measured. ”

Garret Graves, head of the coastal protection authority, refused The Lens’ request for comment.

The national fisheries service letter included suggestions on how the coastal authority could address its concerns. Some of the suggestions, such as closing diversions during spawning seasons for some species, already are under consideration by the authority. The agency has stressed that operation of the diversions will be adapted to evolving science.

Many of the concerns raised have long been acknowledged and considered the unfortunate cost of saving the rapidly sinking southeastern coastal area of the state. A recent report from the National Oceanic and Atmospheric Administration said the area can expect more than five feet of relative sea-level rise by the end of the century. The average elevation of the region is between two and three feet.

In developing the 2012 Master Plan, the coastal authority ran numerous scenarios projecting the long-term effectiveness and cost-per-acre of land-building techniques. Large sediment diversions were determined to be the most efficient and cost-effective.

The master plan must be resubmitted to the Legislature every five years. Lawmakers must vote the entire plan up or down. It has been approved unanimously in its first two editions, both of which included diversions.

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...