Lake Okeechobee is the nation’s second largest freshwater lake and the largest lake in Florida. It is the heart of the Kissimmee-Okeechobee-Everglades system. The lake provides drinking water for surrounding communities serves as a source of irrigation for a $1.5 billion-a-year agricultural industry that produces sugar cane, winter vegetables, citrus and rice. The lake also serves as a source of water for navigation, recreation and for estuaries. Before south Florida was settled, Lake Okeechobee water levels were controlled by natural conditions and events such as rainfall, runoff from the Kissimmee River, evaporation, and outflows south into the Everglades. As the population of south Florida grew and agricultural communities began to thrive, the State of Florida and the Army Corps of Engineers constructed an array of projects to control the lake’s elevation. In the end, the lake was surrounded by a massive earthen berm, the Herbert Hoover Dike.
AUTHORIZED USES FORLAKE OKEECHOBEE
Congressionally authorized uses for LakOkeechobee include the following:
• Flood and storm risk management
• Water supply for the following: – Salinity control in estuaries– Regional groundwater control– Agricultural irrigation– Municipalities– Industry
• Enhancement of fish and wildlife• Recreation
UNIQUE WATER MANAGEMENT CHALLENGES
In the late 1800s, most of the water from Lake Okeechobee drained slowly to the Everglades. However, man-made canals, levees, and the construction of Herbert Hoover Dike changed the runoff drainage patterns for the lake. This presents several water management challenges to include the following issues:
• Inflows from the Kissimmee River and other streams frequently exceed the ability of the lake to release water. One foot of rain in a saturated Kissimmee and/or Okeechobee basin can lead to a four-foot rise in the lake level.
• The outflow capacity to the Caloosahatchee and St Lucie Rivers far exceeds the capacity to send water to conservation areas and the Everglades.
• Water releases are done in a controlled manner due to constraints on capacity and downstream impacts.
• During periods of dry weather, evaporation removes more water from the lake than any type of water release.
• During periods of dry weather, minimum water releases are necessary to keep salt-water content from rising to quantities that are harmful to marine life in the estuaries.
DECISION MAKING PROCESS
The Corps’ decision-making process incorporates input from the South Florida Water Management District and other stakeholders to determine quantity, timing and duration of the potential releases from Lake Okeechobee includes consideration of various types of data. This information includes, but is not necessarily limited to, the following:
• Central and Southern Florida Project conditions• Historical lake levels• Estuary condition/needs• Lake ecology conditions/needs• Water conservation area water levels• Stormwater treatment area available capacity
• Current climate conditions• Climatic forecasts• Hydrologic outlooks• Projected lake level rise/recession• Water supply conditions/needs
2008 LAKE OKEECHOBEE REGULATION SCHEDULE (LORS)
LORS is the result of a two-year study on water management and lake levels that included significant public involvement. It is difficult to develop a rigid operations system with unpredictable weather conditions and competing demands on lake water.The LORS was developed to balance the performance of multiple project purposes while preserving public health and safety, not to optimize performance of any single project purpose at the expense of another. One of the primary goals of LORS is to maintain a lake level between 12.5 and 15.5 feet. LORS includes a seasonally-adjusted schedule to help guide water management decisions. The three primary bands are as follows:
• HIGH LAKE MANAGEMENT BAND—This band includes lake levels above 16 feet in advance of the wet season, or levels above 17.25 feet during the dry season. In this band, operations are focused on reducing the lake level, freeing up additional capacity for runoff from future heavy rain events. Maximum water releases typically take place in this band.
• OPERATIONS BAND—This band consists of five sub-bands that help guide water managers to appropriate decisions that balance the needs of all users, while maintaining a lake level in the Corps’ preferred range of 12.5 and 15.5 feet. Toward the lower end of this range, the Corps relies heavily on input from the South Florida Water Management District to assist with water allocations.
• WATER SHORTAGE MANAGEMENT BAND—This band includes lake levels below 10.5 feet in advance of the wet season, or levels below 13 feet at the start of dry season. In this band, the Corps generally defers decisions on all water releases to the South Florida Water Management District.
FOR MORE INFORMATION
JOHN H. CAMPBELL
Corporate Communication Office