The Indian Trail Improvement District weathered Hurricane Irma pretty well in terms of controlling flooding, but the ITID Board of Supervisors spent time last week considering options to improve flood control for when a storm hits bringing more water.
The discussion at the Sept. 20 meeting included completing the acquisition of 640 acres dedicated to ITID by developer GL Homes to be used for stormwater retention.
ITID Engineer Jay Foy said Hurricane Irma could have been catastrophic for the district if it had remained on an earlier projected path, which put the eye making a direct hit over Palm Beach County.
Foy noted that The Acreage received about 7.3 inches of rain over a three-day period from the storm, which did not overstress the drainage system, because it had been drawn down as much as possible.
“I don’t doubt that some areas could have received as much as 12 inches,” he said, pointing out that the district’s M-2 impoundment area would have been able to take at least another inch of rain.
“The way the system is operating now at pre-storm drawdown, we can keep our level of service as long as we’re not shut off,” he said.
Supervisor Ralph Bair said the district was lucky that the area had dodged the worst part of the storm.
“To me, the M-2 wasn’t utilized as much as it could have been, and, therefore, we had to go to the Seminole Improvement District to ask them to release the water,” he said.
Foy said the M-2 basin is not connected to the M-2 impoundment and relies on 11 separate internal basins for stormwater catchment.
“Unfortunately, those small basins have no storage, and maybe that’s what could be addressed in a strategic plan,” Foy said, explaining that a low-density development needs about 10 percent of the land for stormwater treatment. “It could be quite costly, but those 11 basins have no storage. The canals fill, and after that it’s the lots. They are not connected to the M-2 impoundment.”
Foy said that ITID answers to the South Florida Water Management District for permission to release stormwater, and to a lesser degree to its intermediaries, the Seminole Improvement District and the Village of Royal Palm Beach.
Supervisor Gary Dunkley asked about the status of the 640 acres that had been dedicated to the district by GL Homes.
“I think it should be a board priority that we get ownership of that 640 acres instead of it staying in limbo,” Dunkley said.
Foy said he had contacted Palm Beach County Senior Planner Bryan Davis, who had forwarded the conditions in GL Homes’ plan, which state that it has to make the conveyance of the 640 acres by April 2018.
“You’re right, we need to get a developer’s agreement in place, and that will be a prime item in that developer’s agreement,” Foy said. “They made that promise, and some other things, but it’s more than a promise — it’s an obligation in the comp plan.”
Dunkley asked whether he needed to make a motion directing staff to complete the process, and ITID Attorney Frank Palin said he had already begun the process.
“GL is in the development process with the county,” Palin said. “They’re going to have public hearings on their alternative plan to flip to the Agricultural Reserve sometime in January or February. I have to talk to GL Homes about this, but I’d like to have an agreement back by December.”
He pointed out that GL Homes made other commitments to ITID in addition to the 640 acres.
“They’ve changed a bit because Iota Carol got involved and [GL Homes] came in with an alternative combining their efforts with Iota Carol,” Palin said. “Iota Carol got eliminated by the county, so it’s a little unclear, but we’ve got a stack of commitments.”
Supervisor Betty Argue said she was under the impression that GL Homes had already committed to dedicating the 640 acres to the district.
“Trying to make some new deal that includes the 640 acres isn’t something that we don’t already have,” Argue said, adding that GL Homes had committed to reimbursing the district for expenses it had incurred for engineering, attorney fees and other functions, and that GL Homes had also committed to activating units once they are developed.
She said GL Homes should also pay for construction trucks’ impact on district roads, whether the development is in agricultural or residential use.
Supervisor Ralph Bair said that the district still does not know if the 640 acres is usable for stormwater retention. “Do we have any bore samples or anything?” he asked.
Foy said he had looked at preliminary studies that show that there is nothing preventing the land from being used for stormwater retention. “We also think there is no restriction on an above-ground impoundment,” he said. “We don’t have any idea of what the soils are underneath. We don’t know if they’re usable or not.”
Bair said he was interested in seeing whether any of the material on the site, which is not far from Palm Beach Aggregates, can be used for district roads. He also wants to look into alternatives to putting a levee around the area, which is estimated to cost about $5 million.
Bair said he also wants to further explore the pump pilot project that had been done in cooperation with the City of West Palm Beach, pointing out that the district has possession of the pump station with no conditions placed on it.
Foy added that during the storm, West Palm Beach had not drawn down its water level in its water catchment area.
“They need to start considering drawdown as part of the flood-control system, and we need to consider discharge as part of their water supply,” he said. “It doesn’t go one way.”
Argue asked Foy why the city did not draw down its M Canal before the storm, and Foy said that West Palm Beach operates under two motives: environmental preservation of the Grassy Waters Preserve and water supply. “Both are in opposition to flood control,” he said.