LAKEWOOD RANCH -- Tropical Storm Andrea caused the banks of the Braden River to overflow into parts of Lakewood Ranch, which accelerated erosion along the tributary's banks.
Most floodwaters went places expected by planners so precautionary measures protected landscape and construction from river overflow. But erosion begun before the storm was encouraged from the extra flow.
When Community Development District 4 meets at 10 a.m. Wednesday, the board will consider erosion remediation options presented by engineer Norman Robertson of Atkins North America. The firm was hired by
CDD4 to evaluate erosion prior to Andrea.
"Based on what I saw, and I was out there with the guys this morning, we probably lost at least 2 feet of bank," said Joseph Sidisky, CDD4 board member, serving Greenbrook. "The potential for damage to the trails, or damage to the lake just on the other side of the trails, is certainly there and we don't want this to develop at a rate that it will become more costly than it is now."
Sidisky, a frequent trail user, checked the Braden River when the water was within a foot of the top of the bank Sunday. Nearby, a part of the trail had washed out where webbing underneath protected the infrastructure. Areas of Adventure Park remained under water.
Not all park users were discouraged by the storm. Staff member Mike Basilone said he saw about 20 youngsters jumping off the pedestrian bridge and enjoying the river water.
"Girls, boys, everybody," he said. "We had some washouts on the back side. I put the rake in and it came back about 6 feet."
Normally, the Braden River runs about 2 or 3 feet deep.
"There was a pretty good velocity of floods through here," said maintenance manager Paul Chetlain, who pointed out a number of overflow spots where water was still standing in Adventure Park.
Erosion has been a concern for a while now, Sidiski said. "I feel we're at a point we need to do something about it," Sidiski said.
Erosion remediation options include:
Cover the area with geofabric anchored into the bank and allow some kind of vegetation to grow through it.
Lace bags of concrete throughout the area. Over time, water would cause the concrete to harden and create sufficient surface resistance to erosion. It would take quite a few bags, Sidiski said.
The Braden River erosion goes down quite a distance, according to Sidiski.
"Usually it's very low and quite frankly the way that I see it, we have estimates in the $30,000 to $40,000 range from the engineering firm. We're not doing anything with urgency on this thing but I think the pressure to do something is increasing at this point."