ST. CHARLES PARISH, LA (WVUE) - Critics of the state's plans for large sediment diversions blasted a test being run at the existing Davis Pond diversion, insisting it threatens the next generation of brown shrimp.
The state's Coastal Protection and Restoration Authority said the two-week test, which wraps up Wednesday, will help answer questions about ambitious plans to pump Mississippi River water into the surrounding marsh for land creation..
For the last 14 days, the state has run Davis Pond on the west bank in St. Charles Parish at full blast, nearly 10,000 cubic feet per second.
Scientists with the Water Institute of the Gulf are measuring pollutants-- nutrients in the river-- at this time of year when the larger diversions would run.
The Save Louisiana Coalition, a group opposed to diversions in the state's coastal master plan, argues the timing could not be worse.
"It's not just salinity that can affect the larvae stages of brown shrimp," said George Ricks, a charter boat captain and spokesman for the coalition.
Ricks complains colder, polluted fresh water from the river could devastate shrimp larvae at a critical point in the growing season.
"It's when the water temperature gets to 68 degrees, everything starts to happen with the larvae stage of the shrimp," Ricks said.
"When you drop that water temperature to 45 degrees, it could wipe out a whole generation of brown shrimp."
The state says it was working with a short, five-week window in which to conduct the test.
However, that butts up against a critical period for shrimp larvae, roughly March 25 to April 15, when water temperatures in Barataria Bay rise into the upper 60's and promote growth.
"Wildlife and Fisheries does sit on the committees that make the recommendations of the flows for the diversions," said Kyle Graham, CPRA Executive Director.
Graham said state biologists "have been consulted all along," noting the state took care to see the test was wrapped up by March 25.
Ironically, the Davis Pond test is designed to answer some of the most serious concerns of critics, who argue the modern, polluted river no longer has the potential to build large amounts of delta.
The answer to that question is key to the state's plans for a series of sediment diversions on both sides of the river, including four being studied at various points south of New Orleans.
Supporters of diversions argue they are an essential tool in mimicking the Mississippi's land-building powers and pushing back salt water eating at the Louisiana coast.
Without diversions, they argue, the state would be forced to settle on a much smaller footprint of islands, ridges and marsh that serve as vital natural hurricane defenses.
Later this year, the state hopes to move forward with engineering and design work on at least one diversion, and possibly a second.