SFWMD, ITID Pondering Designs For Corbett Berm

South Florida Water Management District officials conducted a public workshop Friday, April 26 regarding a planned levee to reinforce the berm separating the J.W. Corbett Wildlife Management Area from The Acreage.

SFWMD Bureau Chief of Engineering & Construction John Mitnik explained that the need to strengthen the levee became apparent last August when Tropical Storm Isaac dumped about 15 inches of rain on The Acreage, which brought flooding to the community and high water levels in the Corbett area that exerted increased pressure on the existing berm that separates Corbett from residents in the northern reaches of The Acreage.

“At that time, the South Florida Water Management District was called upon to come in and provide some temporary repairs to that existing berm, as well as construction of a temporary outlet through the construction of a weir that would allow some of those waters at those high stages to bleed off out of Corbett into the [adjacent] Mecca property and be directed back north to the C-18 Canal,” Mitnik said.

After those temporary measures were put in place, Gov. Rick Scott directed the SFWMD and other agencies to come together and develop a plan to strengthen the integrity of the existing berm.

Since that time, water managers have been doing preliminary studies and conceptual designs, as well as some of the geotechnical work and topographical surveys that are required to support the design. The SFWMD has also done wetland mapping to see what designs would minimize the impact to the Corbett area.

“Obviously, you want to minimize those impacts as much as possible,” Mitnik said.

Mitnik presented several different conceptual designs for the levee, all of which leave the existing levee in place, with some taking varying amounts of land inside Corbett — an idea opposed by conservation organizations — and other designs on the ITID side of the existing berm.

Difficulty of construction and the overall cost are other factors that will need to be taken into consideration. Seepage is another factor that will have to be looked at closely, because a certain amount of seepage is necessary to maintain the water table in The Acreage, Mitnik said, adding that other ideas and concepts might be incorporated through the design process, which will continue through the spring and summer.

Drew Martin on behalf of the Sierra Club said there are some questions that have not been answered.

“I like the fact that you have not just settled on going into the Corbett area,” Martin said. “I like the fact that you’re looking now at doing something in the Indian Trail Improvement District that does not require going into Corbett, because overall the Sierra Club is opposed to taking land away. Palm Beach County has just a limited amount of wildlife habitat and recreational lands. Every time there is a problem, we don’t like the solution to be, ‘Let’s go take some land.’”

Martin was also concerned that flooding in The Acreage was caused by excessive rain rather than water from Corbett. “Whether the berm is fixed or not isn’t going to change the fact that the property got an excessive amount of rainfall and there was not adequate drainage to protect those properties,” he said. “You can’t really solve that problem through building a berm.”

Martin was also concerned about how the county continues to allow development on vacant land in the area, when they should be looking at the vacant land as a place to hold water.

Mitnik said the existing berm showed signs of instability during the flooding, although it did not actually fail. He said the goal is not to change water control levels for Corbett, which is 22.5 feet, or ITID, which is 16.5 feet, but to see that the integrity of the levee is secure.

SFWMD Director of Engineering Jeff Kivett said the ground level on both sides of the levee is about 20 feet but Corbett wants to keep the water level higher to improve the wildlife habitat.

“It’s that difference in those elevations that we want to manage that so that we don’t interrupt each other’s operations in that general area,” Kivett said.

Acreage resident Patricia Curry was concerned about the cost of a new levee, about the impact of seepage with some of the proposed designs, and the impact to Corbett. “I don’t know why our existing berm cannot be shored up to make it much more stable and save everybody a heck of a lot of money,” Curry said.

Martha Musgrove, representing the Florida Wildlife Federation, said she appreciated the purpose of the levee but did not want to give up any Corbett land. “We need the resolution of a problem that works on both sides,” she said.

Musgrove also pointed out that the current conceptual plans for the levee would obliterate the temporary weir that was built during the flooding to allow excess stormwater to flow from Corbett into the Mecca property, which still has agricultural canals that can move water into the C-18 Canal. That would have a beneficial effect in getting runoff to the Loxahatchee River.

Musgrove said she thought the SFWMD was on the right track and asked that they get some cost estimates and do it as simply as possible.

“The Florida Wildlife Federation wants to protect the wetlands,” she said. “That’s one of our prime goals, to protect the Corbett area. We helped establish it, and we’re not giving it up.”

Mitnik said the SFWMD will probably be able to come back sometime during the summer with plans that take into consideration input from last week’s meeting.