An edition of: WaterAtlas.orgPresented By: Sarasota County, USF Water Institute

Water-Related News

Florida's outdated urban drainage systems cause more flooding, but there' a natural solution

In the 1900s, swamps and low-lying areas were drained to create more space for development and farming.

Florida has a lot of altered drainage networks, like ditches and canals, but at a recent resiliency summit in Clearwater, it became clear that these are increasingly becoming obsolete and can actually make flooding worse.

There are 80,000 linear miles of stream channels in Florida, and almost two-thirds of those are ditches and canals.

These water systems were originally put in to drain parts of the state for development.

But John Kiefer, an environmental engineer with Black & Veatch who moderated a panel discussion on the subject at the Regional Resiliency Summit, said these are not stable.

"They require perennial maintenance, otherwise they erode — sometimes catastrophically, sometimes chronically," Kiefer told the audience in one of the breakout rooms at the Hilton Clearwater Beach.

He said the eroding sediment could plug up openings, compounding the flooding that's already increasing from climate change.

Along with sea level rise, warmer temperatures cause more water to evaporate from the land and oceans, creating more frequent and heavier rain events.

Kiefer also said altering the landscape causes problems for wildlife, so some fish don't have access to proper water bodies, for instance.

"So, what is the cure? Well, the cure can follow a gradient from near to natural solutions to highly engineered ones," Kiefer said.

These systems can be re-patterned so they process water and sediment more naturally.

Take Sarasota County's Phillippi Creek Watershed, for example.

Kiefer said 95 of the 100 miles of canals there are eligible for this kind of restoration, but a project like this could cost $2 million per mile.