The decision by top state officials to change how future interstate median barriers will be built is a step in the right direction, an attorney involved in the issue said Tuesday.

But Joshua M. Palmintier, an attorney for plaintiffs in a lawsuit that claims the concrete dividers added to the flooding in Livingston Parish last year, said what to do about existing barriers on Interstate 12 remains a key question.

Palmintier, in response to questions, took issue with comments by state Transportation and Development Secretary Shawn Wilson.

Wilson said last week it is not financially feasible to replace the current barriers on I-12, which critics contend created dam-like conditions on the interstate that restricted the flow of water.

"I would respectfully disagree with that," Palmintier said.

"I think what we need to do is take a long look at exactly what can be done, and I think it is cost prohibitive if you don't do it because if they don't do it it is going to happen again," he said.

Palmintier said damages to the region range from $500 million to $3 billion.

"To do nothing in reference to the existing wall ... would be a huge mistake financially for the state," he said.

Wilson, whose agency is the chief target  of the lawsuit, said future interstate barriers will be different than those at the center of the legal action, including plans to widen I-10 between Highland Road and La. Hwy. 73 in suburban Ascension Parish.

He said the new design will include "barrier slots" to allow water to drain off the interstate during heavy rain.

Wilson said the plans are not an admission of guilt that the previous design was flawed.

He said he is taking the action in response to a 1,000-year flood.

"I think that them discontinuing what we believe is a faulty design, an ineffective design, is at least a step in the right direction," Palmintier said.

"However, it is just a first step," he added.

Palmintier represents the cities of Walker and Denham Springs, Livingston Parish and the Livingston Parish School Board, among others.

The lawsuit, which was filed on January, is embroiled in a jurisdictional dispute.

Wilson said the newly-designed barriers are only meant to get  water off the interstate, not serve as some sort of general drainage solution.

The "barrier slots" are supposed to be 2 inches tall, 10-12 inches wide at the bottom of the slab and be spaced 12-20 feet apart.

"I don't know that the new design is sufficient to stop flooding," Palmintier said.

"However, anything is a step in the right direction," he said. "It is good to hear they are at  least  listening to people of that region."

The area in dispute includes the barriers on I-12 extending 19 miles east of Baton Rouge.

When the lawsuit will move into substantive arguments is unclear.

The challenge was filed in the 19th Judicial District Court in Baton Rouge. It was then moved to federal court before, at the request of plaintiffs, the lawsuit was returned to state court.

That order is being appealed to the 5th U.S. Circuit Court of Appeals.

A separate lawsuit naming DOTD contends the construction on I-12 worsened flooding in Tangipahoa Parish.

Follow Will Sentell on Twitter, @WillSentell.