A rule change proposed by the Trump administration would be devastating to Florida wetlands and to the vital role they play in protecting millions from flooding, polluted water and other health and safety threats. With toxic algae blooms regularly hurting the health and economy of a growing state, the last thing Florida needs is a federal rollback of water protection efforts. Gov.-elect Ron DeSantis, an ally of the president who has said that water quality will be an important priority for his administration, should add his voice to those opposing this dangerous proposal.The change, unveiled in December by the Environmental Protection Agency and U.S. Army Corps of Engineers, would create a new definition of federally protected wetlands. The new rule says that the only wetlands that would be federally protected are those immediately adjacent to a major body of water, or ones that are connected to such a waterway by surface water. As the Tampa Bay Times' Craig Pittman recently reported, that narrower definition would leave an estimated 6 million acres of Florida’s wetlands vulnerable to developers and other interests that seek to wipe them out, according to figures from the EPA. That's half of Florida's 12 million acres of wetlands. The new definition would remove federal protection under the Clean Water Act from about 51 percent of all of the nation's wetlands.That wholesale gutting would have a disastrous impact on water quality. Wetlands act as natural pools to hold water in rainy times, serving as a first line of defense against flooding. They also filter pollutants from the water before it reaches the drinking water supply. Both are critical protections in a highly urbanized and growing state. And the timing couldn't be worse, as Florida has suffered through a second year of chronic outbreaks of toxic algae bloom, and as global warming is creating an environment of more extreme and damaging storms, which coupled with sea level rise pose increased risks to millions in coastal areas like Florida.Acting EPA administrator Andrew Wheeler called the change a way to make wetland regulations “simpler and clearer” for landowners. Not surprisingly, it was hailed by home builders, developers and farmers who have complained that wetlands regulations unduly infringe upon their property rights and businesses. The impact on Florida would be substantial, given the state's flat topography and heavy seasonal rains, which help to recharge downstream Florida waters. A larger portion of Florida’s surface is covered by wetlands than in any other state.The Obama administration served the state's distinct needs by expanding the definition of protected waters to include streams where water runs only during or after rainfall, building on protections first put in place by former President George H.W. Bush. The Obama-era rules also protected wetlands that were only connected to waterways through an underground connection such as the Floridan aquifer. But the change was unpopular with farmers and developers, and the federal courts have not provided the clarity or consistency that both sides need. The rule change amounts to a campaign promise kept by Donald Trump during his presidential bid. The administration will take public comment on the plan for 60 days before finalizing the rule early this year. Some states are virtually certain to challenge the rollback in court.DeSantis, Trump's hand-picked choice in Florida's gubernatorial election, should make clear to the president that the rule change is bad for Florida's environment, public welfare and economy. The state's water supply and flood control need robust protection, and Trump's plan guarantees the opposite.