Future interstate median barriers will be built differently than those at the center of a lawsuit that says the concrete dividers worsened flooding in Livingston Parish last year, Louisiana's transportation chief said Thursday.

Shawn Wilson, secretary for the state Department of Transportation and Development, also said the plans are not an admission of any wrongdoing by the state for previous work.

"Shawn is not doing this because DOTD got sued," he said in a 30-minute interview. "Shawn is doing this because we had a 1,000-year flood."

Wilson said that, since the flood of August 2016, officials reviewed the issue and concluded that changes on future work make sense.

"I have made the decision that, if we are going to build a barrier wall, it will have a barrier slot associated with it," he said.

The key part of the redesign means that barriers will include slots to let water drain off the interstate during heavy rain.

Wilson said the "barrier slots" will be 2 inches tall and 10-12 inches wide.

The openings will be at the bottom of the slab and be spaced around 12-20 feet apart.

Wilson emphasized that the new design is not meant, or capable, of preventing flooding beyond the roadway during severe weather.

"I don't want the public to see this and say 'Hey, we are going to get drainage to prevent flooding,'" he said. "It is not."

The issue has been a volatile topic for months after Livingston Parish officials accused DOTD of contributing to flood problems that swamped the parish, and other parts of the Baton Rouge area a year ago.

A lawsuit filed by the cities of Walker and Denham Springs in January contends the Interstate 12 barrier extending 19 miles east from Baton Rouge essentially created a dam that restricted the flow of water during the flood.

The legal challenge, which targeted DOTD and a variety of firms, is pending amid jurisdictional disputes.

Rick Wentzel, superintendent of the Livingston Parish school system, applauded Wilson's decision Thursday but asked what will be done for existing barriers on I-12 that he blames for the flooding of his home last year.

"There is no doubt in my mind that there had been slots or anything of that order water would have moved away from where I live for sure," Wentzel said.

The superintendent, who lives in Walker, got 28 inches of water in his home.

Wilson said the redesigned barriers are for future construction.

"Is it financially responsible to remove every wall of the interstate that we built? Wilson asked. "I don't think so."

"Is it financially responsible for me to design going forward a wall that has a barrier slot? I absolutely think that makes sense," he said.

The concrete barriers are meant to prevent crossover accidents on heavily-traveled interstates, where motorists routinely travel 70 miles per hour or more.

They are typically 2 1/2 to 4 feet tall.

The state has about 900 miles of interstate but the barriers exist on about 50 miles or so.

The concrete barriers are different from cable barriers, which cover about 200 miles of roadways now and about 600 miles eventually.

One of the first projects that will see the new barriers is the $72 million widening of Interstate 10 between Highland Road and La. Hwy. 73 in suburban Ascension Parish.

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The same applies to a 15-miles stretch of I-10 between I-49 and the Atchafalaya Basin. The cost is $179 million.

Also, a $22 million project on I-12 near Satsuma will include the redesigned barriers.

Wilson said costs of the changes will be minimal.

DOTD is also named in a second lawsuit, filed in March, that contends the construction of I-12 worsened flooding in Tangipahoa Parish.

That challenges says a section of the interstate that crosses a floodplain had inadequate openings for water to escape.

Follow Will Sentell on Twitter, @WillSentell.