Just how low will Lake Okeechobee go during South Florida’s lingering drought?
That is the question driving everything from South Florida lawn watering restrictions to the survival of the endangered Everglades snail kite.
Lake Okeechobee is South Florida's primary backup water supply as well as a vital wildlife habitat.
The lake on Thursday measured 11.25 feet above sea level, which was more than 2 feet below normal and more than 3 feet lower than this time last year.
Declining lake levels were a key factor in the South Florida Water Management District's decision in March to impose twice-a-week landscape watering limits from Orlando to the Keys. South Florida golf courses and agriculture were required to reduce water use by 15 percent.
The district's long-term forecasts this month project a greater than 50 percent chance that the lake will dip below 11 feet before the start of the summer rainy season.
If the lake drops below 10.5 feet, it would be too low for gravity to send lake water to the drainage canals south of the lake that sugar cane growers and other agricultural operations tap for irrigation. At that point, the district plans to install temporary pumps to keep the irrigation water flowing.
But those pumps raise concerns for environmentalists worried about the demands of irrigation worsening the drought’s strain on the habitat of the already-suffering snail kite.
When the lake hits 10.5 feet, 80 percent of the marshes along the edge of the lake would be dried up, threatening the feeding and nesting area key to the snail kite's survival.
The snail kite is a medium-sized bird of prey that feeds primarily on apple snails that live in the lake’s marshes and the Everglades.
During the last 10 years, the snail kite population plummeted from 3,000 to about 700. An extended drought could cut the remaining snail kite population in half, according to Audubon of Florida.
Audubon advocates additional watering cutbacks for South Florida homes and farms alike to reduce the strain on water supplies and lessen Lake Okeechobee water withdrawals.
District officials so far have resisted going beyond twice-a-week watering cutbacks. After South Florida’s driest October-to-February span in 80 years, normal rainfall levels returned for the month of March and that slowed Lake Okeechobee’s decline.
Of course, it’s a history of manmade manipulations of Lake Okeechobee’s water level that worsen the water supply strain during droughts.
Lake Okeechobee once naturally overflowed its southern rim, sending sheets of replenishing water slowly rolling to the Everglades.
Decades of draining South Florida and pumping water to make way for agriculture and development led to building the dike around Lake Okeechobee – turning it into South Florida’s largest retention pond.
During Florida’s rainy season, safety concerns about the lake’s 70-year-old, earthen dike lead the Army Corps of Engineers to dump lake water out to sea to avoid flooding. The corps tries to keep the lake between 12.5 feet and 15.5 feet.
In 2010, the corps dumped more than 300 billion gallons of water out to sea because South Florida has too few storage options to save the water for times of need.Copyright © 2015, The Baltimore Sun