In what it sees as a blunt message to the state Legislature, the St. Bernard Parish Council today plans to pass an ordinance prohibiting construction of the river diversions within its jurisdiction called for in the state’s 2012 Master Plan for the Coast. (Update: The measure passed.)

While acknowledging that state law likely preempts council action, Councilman George Cavignac said the panel believes the ordinance is a necessary step in getting lawmakers to hear criticism of the diversions, which are opposed by a vocal group of commercial and recreational fishers.

“Our communities have been voicing a lot of concerns, but we’re having no luck going through the normal mechanisms with the CPRA [Coastal Protection and Restoration Authority],” Cavignac said. “Hopefully this is one way to tell them [the Legislature] that we are really concerned about this.”

Garret Graves, head of the Coastal Protection and Restoration Authority, said the state’s plan must be implemented in its entirety to rebuild land as planned. Without action, he said in an email, “projections show St. Bernard Parish’s future is in deep water.”

The Legislature has unanimously approved the Master Plan twice. With sea level rising, the plan identifies large river diversions as the most economical and efficient tool to deliver the volume of river sediment required to build up Louisiana’s sinking coastal wetlands. It acknowledges the freshwater in the estuaries likely will push some species of shrimp, fish and oysters toward the open Gulf.

Fishers who oppose the dislocation say rebuilding the coast could be accomplished solely by pumping sediment from the river into the sinking basins. While the Master Plan proposes to spend more money on such slurry pipelines, as they’re called, the plan designers contend that maintaining them against continued subsidence would be too expensive.

As the projects move closer to construction, opposition among fishing groups in coastal parishes has grown louder, and some scientists, concerned about pollutants in the river water, have backed the fishing groups.

Graves said the state has committed “several million dollars” to an independent scientific panel to study such concerns.

“Like the St. Bernard Parish Council, we believe that decisions need to be made based upon science rather than speculation,” he said. “The Master Plan is based upon the best science and the plan works as a system.  You cannot just cherry pick some components and leave others on the shelf.”

Because the projects in St. Bernard are several years from construction, Graves said, “we have plenty of time to work through any potential issues.”

Cavignac said the council was “trying to get the Legislature to look more closely at what the communities are concerned about.”

However, current law gives the Legislature only limited oversight. While the Coastal Protection and Restoration Authority must present an updated plan every five years, lawmakers can only vote the plan up or down, not make amendments.

Cavignac said the council is putting its ordinance in a resolution concerning flood-plain management that’s required by the National Flood Insurance Program. It can be found in the agenda for Tuesday’s meeting in the attachment to Item 23, entitled “Chapter 10.5 FLOOD DAMAGE PREVENTION.”

In Sec. 10.5-4 “METHODS OF REDUCING FLOOD LOSSES,” item No. 5 states [the ordinance will] “prevent or regulate the construction and/or alteration of flood barriers or other structures which will unnaturally divert waters onto any area within the jurisdiction of St. Bernard Parish or which may increase flood hazards to other lands.”

The ordinance goes on to define diversionary structures as “structures engineered and constructed to intentionally divert water and/or sediment from one riverine source to another area within the jurisdiction of St. Bernard Parish (does not include Parish Council-approved structures and/or operations following the adoption of this ordinance).”

This story was updated after publication with comments by Garret Graves.