Declining Lake Okeechobee water levels once again threaten to generate water-supply ripple effects that spread throughout South Florida, leaving less water for thirsty crops and lawns as well as an ecosystem trying to rebound from years of abuse.
The big lake is South Florida's backup water supply, relied on to replenish drinking water supplies for some communities and tapped for irrigation by sugar cane growers and other farmers.
During droughts, the lake also is a barometer for water conditions across the region. Low lake levels are one of the big factors that can result in emergency watering restrictions, which could further cut back on the watering days allowed for homes and businesses across South Florida.
The South Florida Water Management District projects that by the end of this month the lake could drop low enough to trigger tougher watering restrictions. Those emergency restrictions would start with farms and towns immediately south of Lake Okeechobee and, if drought conditions worsen, spread to the rest of South Florida.
"Hold on tight. This summer is not going to be pretty," said Carol Wehle, executive director of the South Florida Water Management District. "We are just going to have a horrible drought unless something changes."
While competing water users vie for more lake water, the health of the lake suffers from decades of draining, dumping and other manipulation to make way for agriculture and development.
Just as the health of the lake has begun to rebound following years of up-and-down water levels, the looming drought and growing South Florida water demands threaten to drain away signs of life.
"The human influence just makes all these things swing much more dramatically," Audubon of Florida scientist Paul Gray said. "We have this lake and water-level system that isn't working for anybody."
DECLINING LAKE OKEECHOBEE WATER LEVELS
On Monday, Lake Okeechobee measured 12.46 feet below sea level. That was about a foot below this time last year and more than two feet below average.
That's about 4 inches away from triggering an initial round of watering restrictions for agriculture south of the lake, as well as lakeside communities. If the lake's decline continues, those restrictions could spread to more of South Florida.
Recent rains helped slow the pace of the lake's decline.
"It's all kind of fuzzy, depending on what kind of rain we get," Tommy Strowd, district deputy executive director, said about the outlook on how far the lake could drop this year. The lake, he said, "becomes kind of the large regional indicator we look at of where we are."
South Florida remains in the midst of its winter and spring dry season. The last three months turned out to be the driest October-to-December span in nearly 80 years, with an average of 2.97 inches of rainfall from Orlando to the Keys.
Ideally, officials want the lake to remain between 12.5 and 15.5 feet.
LOW LAKE LEVEL EFFECTS ON AGRICULTURE
If the lake drops below 10.5 feet, it's too low for gravity to fill the drainage canals that send lake water south to supplement irrigation for hundreds of thousands of acres of sugar cane, vegetables and other crops in the Everglades Agricultural Area.
That would prompt the South Florida Water Management District to use temporary pumps to keep lake water flowing south.
But those pumps aren't capable of delivering the usual allotment of lake water relied on to boost crops.
Growers already are expecting temporary watering restrictions that could start this month if lake levels keep dropping.
The first phase of emergency restrictions would require agricultural operations immediately south of Lake Okeechobee to cut back on water use at least 15 percent.
Aside from sugar cane, irrigation cutbacks hurt farmers growing rice, corn and vegetables, said Charles Shinn, who monitors water issues for the Florida Farm Bureau.
Emergency watering restrictions that start with agriculture can be expected to extend to South Florida homes and businesses if drought conditions worsen, Shinn said.
"It's going to happen," Shinn said. "I don't see anything that turns the [lake] direction around."
LOW LAKE LEVEL EFFECTS ON SOUTH FLORIDA RESIDENTS
In addition to the lake, water levels in local well fields and the Everglades water conservation areas drive decisions about watering restrictions.
Back in 2007, when the lake hit its all-time low, the district imposed its toughest watering restrictions ever by only allowing only once-a-week watering in much of South Florida.
Last year the district for the first time imposed year-round landscape-watering restrictions to try to increase conservation. The idea was to stretch existing supplies and make it easier to conserve during droughts.
While the new year-round rules allow three-day-per week watering for most of Southeast Florida, Broward and Miami-Dade counties opted to go with tougher twice-a-week watering limits. Palm Beach County allows watering three days per week.
If conditions worsen, one of the first moves to increase conservation could be to switch Palm Beach County and others to twice-a-week watering.
"We still have arrows in our quiver, depending on how low water levels go," said Pete Kwiatkowski, the district's water-shortage team leader..
LOW LAKE LEVEL EFFECTS ON ENVIRONMENT
Scientists say Lake Okeechobee is as healthy as it has been in years, after recovering from previous droughts and getting bypassed by hurricanes that bring an influx of water and stir up polluted lake sediment.
Improved water clarity allowed submerged grasses such as eel grass and pond weed to return. That helped bass and other fish populations. Noisy moore hens along with grey blue herons, coots and sandhill cranes stalk the marshes looking for prey.
But when the lake drops below 11 feet, the risk grows for more environmental damage in an ecosystem already punished from decades of pollution and manipulated water levels.
Hitting the 10-foot-range for too long means water receding past the marshes rimming the lake and drying up life-giving habitat home to young fish, wading birds and other wildlife.
That includes some of the last remaining habitat of the endangered snail kite — a medium-sized bird of prey that feeds primarily on the apple snails that live in Lake Okeechobee's marshes and the Everglades.
Snail kite populations nosedived from 3,000 a decade ago to just 700 today, according to Audubon. That follows years of yo-yoing water levels in Lake Okeechobee that hampered apple snail populations.
Three months of dried out lake marshes starts killing off apple snails and taking away the finicky snail kite's main food source.
A new drought could threaten a hoped-for snail kite recovery. Audubon considers the snail kite a barometer for the overall health of the lake.
"The problem is the long-lasting effects," Gray, of Audubon, said about the potential for a prolonged drought. "Every time it happens, it takes a long time to recover."
The real concern would be this year turning into the first of a multi-year drought, Florida Fish and Wildlife Commission biologist Don Fox said.
"We'll have to see how bad the drought goes," said Fox, who has been working on Lake Okeechobee for decades. "I don't see the doom and gloom, but let's see where we are in June.
Andy Reid can be reached at abreid@SunSentinel.com or 561-228-5504.
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