An old source of Lake Okeechobee pollution could return after South Florida water managers Thursday opened the door to renewed "back-pumping."

In a bid to boost water supplies, the South Florida Water Management District board agreed to explore pumping some of the polluted stormwater that drains off South Florida farmland back north into Lake Okeechobee for storage.

The district stopped that controversial practice five years ago because of environmental concerns about sending water containing polluting phosphorus as well as pesticides into the lake.

But the district, now under new leadership, has agreed to pursue a watered-down back-pumping proposal that would redirect less farmland runoff water back into the lake than in the past.

Supporters say back-pumping during the rainy season would make more water available for agricultural and environmental needs during droughts.

"Let's look at every option," said district Board Member Daniel DeLisi, who pushed for the back-pumping measure. "We can not back down from looking for a solution."

Environmental groups and the U.S. Department of the Interior counter that the potential increase in pollution isn't worth the water supply boost that comes from allowing back-pumping.

They favor cleaning up the water and using it to replenish the Everglades, instead of pumping it north.

Twelve environmental groups, including Audubon Florida and the Sierra Club, signed a letter opposing the back-pumping proposal.

"The lake is a lake. ... It's not to be used as a reservoir," said Mark Perry, of the Florida Oceanographic Society. "[Back-pumping] adds pollution to the lake and to the estuary downstream."

More phosphorus, nitrogen and other nutrient-rich pollutants that result from farming would flow into the lake if back-pumping resumes. That can lead to algae blooms, fish kills and other damage to the lake's ecosystem.

Back-pumping also seems to run counter to multibillion-dollar Everglades restoration efforts aimed at getting more Lake Okeechobee water flowing south to Everglades National Park.

"Anything that takes water supply from the Everglades is not a good thing," said Joan Lawrence, of the U.S. Department of the Interior. "I'm just skeptical."

District officials say their proposal makes use of water that otherwise would get drained out to sea for flood control and would not lessen water going to the Everglades.

They plan several more months of computer modeling to try to gauge the water supply and water quality effects of back-pumping. The district also still needs state and federal approvals before it can resume back-pumping.

The goal of getting the board's OK Thursday was to revive back-pumping as an option, according to district Executive Director Melissa Meeker.

"Let us go down that path to see if it's possible," she said.

Decades of draining land for farming and development eventually led to corralling Lake Okeechobee with a dike for flood control. It also turned the once free-flowing lake into South Florida's primary backup water supply.

That water supply has been strained more than usual in recent years because the Army Corps of Engineers has been keeping the lake about a foot lower year round due to safety concerns about the lake's dike - which is in the midst of a slow-moving rehab.

District officials bill back-pumping as a way to find more freshwater that could be stored in the lake and help the Caloosahatchee River during dry times, without lessening the amount of water that Big Sugar and other South Florida agriculture relies on for irrigation.

Sending Lake Okeechobee water into the Caloosahatchee River during droughts provides an infusion of freshwater needed to help protect West Coast water supplies and fishing grounds.

During recent years, West Coast communities have periodically cut off from those lake water releases due to South Florida water supply concerns.

Back-pumping supporters say it provides an interim water supply solution while waiting for long-term fixes that include building costly new reservoirs.

"This is a good plan," said Tom MacVicar, a consultant for South Florida growers. "It's a very targeted, sophisticated ... limited pumping plan."

Environmental groups say there are other water supply-boosting options to back-pumping. That could include more limits on how much lake water agriculture gets in order to make more water available to the Caloosahatchee.

"We've tried [back-pumping] before and we know the result," said Cara Capp, of the Clean Water Action environmental group. "We need to try something different."

abreid@tribune.com, 561-228-5504 or Twitter@abreidnews

Copyright © 2012, South Florida Sun-Sentinel

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