Lake Okeechobee’s declining water level strains urban and environmental water supplies alike, as South Florida waits for drought-quenching summer rains to bring relief.
Lake Okeechobee serves as South Florida’s primary back-up water supply, but on Wednesday it neared the point where it would drop too low to keep sending water south.
That heightens the difficulty for the South Florida Water Management District to meet the sometimes competing water needs of the environment, agriculture and community supplies.
The lake hit 10.57 feet Wednesday, 4 feet lower than this time last year and 2.7 feet below normal.
At 10.5 feet the lake would be too low for gravity to keep sending water to the canals that deliver lake water that sugar cane growers and other agriculture rely on for irrigation.
Those canals also deliver lake water to the Everglades water conservation areas, west of Palm Beach, Broward and Miami-Dade counties.
In addition to hydrating the northern reaches of the Everglades, water in the conservation areas helps supplement community water supplies in southeast Florida.
As of mid May, more than 60 percent of the land in the vast Everglades water conservation areas was dry.
"It becomes very difficult to move water," Susan Sylvester, district director of operations, said about the lake’s continued decline. "We are really looking for those wet season rains to kick in."
The district can temporarily install pumps to keep water flowing south after the lake drops below 10.5 feet, but those pumps move less than half what the canals can usually provide.
The district plans to make a week-by-week evaluation about whether to install the pumps, with the hopes that the summer rainy season will instead bring the water that is needed.
Aside from straining South Florida water supplies, Lake Okeechobee dropping too low threatens wildlife habitat.
Low lake levels already threaten the habitat of the endangered Everglades snail kite and at 10.5 feet, more than 80 percent of the foraging habitat for the snail kite dries out.
The health of the snail kite is considered a barometer for the overall health of the Everglades. Snail kite populations during the past decade have dropped from 3,000 to about 700.
There were 33 active snail kite nests on Lake Okeechobee midway through May, according to the district.
"Water drives ecology," said Deborah Drum, the district’s deputy director of Everglades restoration. "There remains major concern regarding lake level."
South Florida averaged just over 10 inches of rain since the dry season began in October, about 68 percent of normal.
Relief could be coming soon.
Traditionally, Memorial Day marks the beginning of South Florida’s rainiest time of year.
From Memorial Day to July 4, South Florida usually gets about 11 inches of rain, according to the district.
"We need an above-normal (summer) wet season. … Even an average one may not get us out of this," said Pete Kwiatkowski, district water-shortage incident commander.
Manmade manipulations, not just a drought, contribute to South Florida’s water supply strain.
Flood control for communities and farms built on what used to be the Everglades leads to stormwater getting drained out to sea, instead of held for times of need.
Safety concerns about Lake Okeechobee’s aging dike have the Army Corps of Engineers keeping the lake about a foot lower year-round while work continues on decades-long repairs. During 2010, more than 300 billion gallons of lake water was drained out to sea because of flood control concerns.
Dumping lake water out to sea worsens the water supply effects of the periodic droughts that are a natural occurrence for South Florida.
Also, landscape irrigation accounts for about half of the use of South Florida’s public water supply.
To boosts water conservation, twice-a-week landscape watering limits for homes and businesses will remain for the foreseeable future, district officials said Wednesday.
Cutbacks for sugar cane growers and other agricultural users near Lake Okeechobee increase from 15 percent to 45 percent when the lake hits 10.5 feet.