Sediment diversion project on right path, scientists tell state officials

THIBODAUX – Scientists from across the country have determined that the state is on the right path in developing and designing what will be the first sediment diversion for coastal restoration in the state.

The Expert Panel on Diversion Planning and Implementation, organized through the Water Institute of the Gulf, gave its second report and set of recommendations to the state coastal authority at their monthly meeting Wednesday.

The group was put together at the request of the state Coastal Protection and Restoration Authority because of the number of new issues that will arise through the design of a structure that will take sediment from the Mississippi River into the coastal marshes.

Although diversions have been used for decades in Louisiana, they’ve been used for flood control or to enhance fishery production, explained Kyle Graham, the CPRA’s executive director. While the state and its partners have become good at building marsh or other coastal restoration activities, the work becomes much more difficult when the changes involve manipulating the way water flows through the south Louisiana landscape.

The 12-member expert panel will double-check and give advice on how the state is proceeding with the first sediment diversion expected to be located near Myrtle Grove in Plaquemines Parish.

The first report was issued to the state in February, and this second report adds seven new recommendations to the list.

“We fully recognize that a lot of work may already be going on, which is great because it means we’re all going in the same direction,” said John Wells, the panel’s chairman as well as dean and director of the Virginia Institute of Marine Science.

Those recommendations include a request for presentations at the panel’s fall meeting about how the state is approaching the technical issues involved in the diversion design and the status of the state ecosystem modeling. Other recommendations include: Focus river information collection and modeling on how a diversion will operate, review what monitoring information is still needed, do a marsh experiment to look at diversion impacts, and identify the risks and benefits of diversions.

The final recommendation, which is expected to take the longest to fulfill, asks the state to determine how people will interact with these changes.

All of these are things the state is currently working on, said Jerome Zeringue, the CPRA chairman and the governor’s coastal adviser.

“It’s kind of reaffirming to us that we’re heading in the right direction,” he said.

Follow Amy Wold on Twitter, @awold10.