Gov. Ron DeSantis' call last week for eight board members of the South Florida Water Management to resign marks the first time a governor has attempted to make such a sweeping change to one of the state's five water agencies, say longtime state water experts.

"I thank you for your service ... but it is time for a clean reset on the leadership of the board," DeSantis wrote in a letter to the board members he wanted gone. Given the voters' support for his environmental proposals, he wrote, "I look forward to reconstituting the board."

PREVIOUS COVERAGE: Gov. DeSantis demands water agency board resign.

"This is unprecedented," said Estus Whitfield, who served as environmental adviser to four governors.

DeSantis, who on the campaign trail repeatedly blasted the industry known as Big Sugar, had asked water district board members in December to postpone a vote on extending a sugar company lease for land needed for Everglades restoration. He wanted time to get familiar with the issue before the vote. Rep. Brian Mast, an ally of DeSantis who headed his environmental transition team, also asked for a delay.

The board approved the lease extension anyway, citing the need to move quickly as being more important than what the new governor wanted. The $1 million lease allows Florida Crystals to continue farming about 16,000 acres in the Everglades Agricultural Area, even while planning goes on for a $1.6 billion in the same area that was approved by the Legislature in 2017 to try to end environmentally damaging releases from Lake Okeechobee.

"For far too long the South Florida Water Management District has been more accountable to special interests than to the people of Florida," Mast said in a statement after DeSantis demanded the resignations. "That changes today, and I look forward to continuing to work with Gov. DeSantis to find replacements who make our waterways and environment the No. 1 priority."

So far four members have refused to quit, and the chairman questioned whether DeSantis has the authority to remove a board member. Florida law says, "The Governor shall have authority to remove from office any officer of said district in the manner and for cause defined by the laws of this state applicable to situations which may arise in said district." But the question is whether this would constitute such "cause."

Ever since 1972, Florida' water resources have been the responsibility of five management districts, which regulate every aspect of water use, from utility pumping to wetlands development, around the state. The districts employ scientists and engineers, but they are overseen by board members appointed by the governor.

State law specifically says the board members should be chosen from "agriculture, the development industry, local government, government-owned or privately owned water utilities, law, civil engineering, environmental science, hydrology, accounting, or financial businesses."

While unpaid, the board members — and particularly the board chairman — have historically been considered powerful positions that some people used as a stepping stone to political careers, said Emilio "Sonny" Vergara, a former executive director of both the St. Johns River Water Management District and the Southwest Florida Water Management District. The latter, sometimes referred to as "Swiftmud," is the one that oversees the Tampa Bay area.

"Because they're not elected offices, that gives them a certain amount of freedom," Vergara said. "Their responsibility is to the natural resources of the state, not to cater to the population." But politics inevitably gets mixed up in the decisions, he added.

For instance, former Gov. Rick Scott pushed out several water management district executive directors while he was in office, and then with the Legislature's help he slashed their budgets and forced them to lay off scientists and engineers. That robbed the agencies of both power and expertise, Vergara said.

In the past, governors have occasionally passed along a quiet word to a board member or chairman that it was time to head for the door, said Estus Whitfield, who served as environmental adviser to four Florida governors. But except for the 1987 incident, there is no precedent for what DeSantis has called for.

The South Florida Water Management District is by far the largest of the five, and the one dealing with the most complex issues, Vergara said. It's the lead state agency on Everglades restoration. In addition to dealing with local governments across a 16-county area, it also must deal with the U.S. Army Corps of Engineers, the National Park Service, the U.S. Fish and Wildlife Service, two Native American tribes and the complicated political alliances and enmities that are characteristic of life in South Florida.

It's also the one where the stakes are the highest, because the water district is in charge of operating a vast network of pipes, pumps, levees and canals that control the flow of surface water across the region.

"You could kill a lot of people by making the wrong decision," Vergara said. Thus, he said, when Scott appointed as the South Florida agency's executive director his personal attorney, Pete Antonacci, who had no background in water management, "that was a very dangerous thing to do."

Antonacci subsequently got into a dispute with the Fish and Wildlife Service, and made headlines by quarreling with the scientists who were in charge of checking the scientific basis of Everglades restoration, telling them to "tend to their knitting."

PREVIOUS COVERAGE: Scott water appointee tangles with scientists.

So far, three of South Florida's board members have resigned — one before DeSantis' announcement last week, two more since then. Of the ones left, three are facing the end of their appointed terms on March 1.

Vergara said the lesson to be learned is a simple one: "Don't screw with the governor."

Times senior news researcher Caryn Baird contributed to this story . Contact Craig Pittman at craig@tampabay.com.. Follow @craigtimes.