Tag Archives: LOSOM

Lake Okeechobee/Kissimmee Chain of Lakes Update

March 2025 FloridAgriculture eNewsletter

Lake Okeechobee recession is continuing due to Recovery Operations, as well as increasing evapotranspiration and water supply deliveries.

As of February 17th, 2025, the lake stage is 14.04 feet, which is down 0.14 feet over the last week, and 0.56 feet over the last month. The U.S. Army Corps of Engineers (Corps) and the South Florida Water Management District (District) are maintaining Lake Okeechobee System Operating Manual (LOSOM) Recovery Operations where LOSOM release guidance is up to 2,100 cubic feet per second (cfs) at the S-79 structure west into the Caloosahatchee River, 1,400 cfs total east to the St. Lucie River, and max practical releases to increase flow to the south.

Average flows for the last week from Lake Okeechobee to the east and west have averaged 500 and 1,500 cfs, respectively, towards the downstream targets with 1,300 cfs going to the Everglades Agricultural Area (EAA) for water supply, and 1,400 cfs to the stormwater treatment areas (STAs). The lake stage is currently in Zone D2 (see graphic below), where LOSOM guidance without recovery operations being implemented would be up to 750 cfs at S-79 and zero east to the St. Lucie with maximum beneficial flows south.

Discharges made south from the Upper Kissimmee Lakes are being made to reach the June 1st low pool targets. Lake Kissimmee is below schedule with decreasing releases to the river channel.

Figure 1. Lake Okeechobee stage as of 17 February 2025.

The Stormwater Treatment Areas (STAs) are exclusively treating water from Lake Okeechobee. The latest 28-day STA inflow concentrations in the Eastern Restoration Strategies flow path range from 158 to 191 parts per billion (ppb) of phosphorus, with outflows from the STAs ranging from 18 to 26 ppb. Inflow concentrations in the Central flow path range from 83 to 101 ppb, with outflows ranging from 12 t0 17 ppb. The Western flow path, STA 5/6, has had no inflow for the last several months.

Most STA cells, or sections within the whole STA, are near their target stages, but many flow ways still have stressed vegetation conditions. There are operational restrictions in place for most of the STAs for vegetation management and/or construction activities.

Water Conservation Area (WCA) stages are decreasing, and some northern areas have water near ground surface (see depth graphic below). WCA-1 is at and receding with its schedule with no outflows to WCA-2A or to tide. WCA-2A is 0.97 feet above schedule with only water supply deliveries being made to Broward County. WCA-3A is 0.80 feet below schedule with large areas in the south below historical averages, but still above ground surface.

Everglades National Park is continuing to receive water into the dry season based on Tamiami Trail Flow Formula (TTFF) targets. WCA-3A is below schedule and the TTFF calls for 981 cfs from WCA-3A. The S-12C and S-12D structures and the S-333 structures are open and delivering 986 cfs into the park. Hydrologic connectivity within Shark River and Taylor Sloughs has diminished over the past two months, however, depths remain conducive for water flow. The S-356 structure is off, with diminished seepage and lower canal stages. The S-332D and S-200 are pumping water into the detention areas as needed to control South Dade canal stages. The gate from the Frog Pond detention area into Taylor Slough is open. Florida Bay flow and salinity metrics remain well outside of all harm thresholds.

Figure 2. Water Conservation Area water levels as of 17 February 2025.

Lake Okeechobee Enters Recovery Mode

January 2025 FloridAgriculture eNewsletter

The U.S. Army Corps of Engineers (USACE) began releases under Lake Okeechobee Recovery Operations on December 7, 2024.

For the past five years, Lake Okeechobee has experienced several storm events and extended moderately high lake stages. This has led to degraded ecological conditions within the lake, including significant loss of submerged aquatic vegetation (SAV), high turbidity and nutrient concentrations, and negative changes in emergent vegetation.

There are six considerations for implementing Recovery Operations – lake stage not receding below 13 feet in summer, SAV coverage significantly below 11,000 acres, no strong El Nino, nor strong La Niña forecasted for the dry season, lake stage not receding below 11 feet NGVD in the last five years, ecological and Snail Kite conditions, and no water supply concerns. Each of these six of the considerations have been met, and current projections show that conditions this dry season are favorable for success.

The goal of recovery is to lower lake levels before the onset of the wet season to allow for recovery of lake ecology, specifically SAV. The operational strategy for these operations intends to slowly bring water levels down by making moderate, non-harmful releases to the estuaries while also sending maximum beneficial flow south to the Everglades. Lowering water levels will allow light to penetrate to the bottom and allow SAV to regerminate and regrow during the April-July period. Regrowth of SAV in Lake Okeechobee will reduce water turbidity and nutrient concentrations. Improved water quality within the lake benefits the estuaries if significant releases are necessary in the coming seasons/years.

Consistent with the Lake Okeechobee System Operating Manual (LOSOM), the maximum allowable releases under Recovery Operations are:

  • up to 2,100 cfs at S-79 to the Caloosahatchee River Estuary (CRE)
  • up to 1,400 cfs total St. Lucie Estuary (SLE) inflows (S-80 + S-97 + S-49 + Gordy Road)
  • up to 300 cfs to the Lake Worth Lagoon (LWL) at S-271 and S-352
  • up to maximum practicable south at S-351 and S-354

Releases will be made in the most beneficial way possible. USACE will continue to collaborate with South Florida Water Management District (SFWMD) and other partners to evaluate flow and salinity to inform estuary releases on a weekly basis. Depending on conditions, releases will either be made as a pulse, or a constant flow targeted at S-80 and S-79. The releases allowed under Recovery Operations are within the RECOVER optimal flow envelope for the estuaries and will not impact oyster spawn, sea grass, spawning, or other ecological activities.

Flow south from the lake has started to increase significantly, as water supply demand has picked up early in this dry season. Flow south to the Everglades will occur based upon capacity of the state’s Stormwater Treatment Areas (STA’s) and the capacity of the Water Conservation Areas (WCA’s) to the south. The capacity of those will generally increase as we move through the dry season.

Exactly when and how much to release within limits will be based on the considerations including, but not limited to, coordination with stakeholders and partner agencies, current and historical lake levels, recession rates, climate outlooks, El Niño-Southern Oscillation (ENSO) forecasts, precipitation forecasts, drought conditions, water-supply conditions, and nesting activities and ecological conditions in the lake, Northern Estuaries, and the Greater Everglades. USACE is constantly monitoring the entire system, and the recovery releases and strategy can be discontinued at any time throughout the dry season if warranted.

New Regulation Schedule for Lake Okeechobee Announced

July 2024 FloridAgriculture eNewsletter

Pursuant to the National Environmental Policy Act (NEPA), the U.S. Army Corps of Engineers, Jacksonville District (USACE) has issued a Notice of Availability for the Lake Okeechobee System Operating Manual (LOSOM) Final Environmental Impact Statement (EIS). USACE is proposing a new regulation schedule for Lake Okeechobee within an updated Water Control Plan (WCP).

The regulation schedule is a compilation of operating criteria, guidelines, and figures that govern the quantity, timing, and duration of releases out of the lake. The regulation schedule establishes the agency’s operational strategy to balance the congressionally authorized project purposes for flood risk management, water supply, enhancement of fish and wildlife, navigation, and recreation. Implementation of this regulation schedule corresponds with the completion of the Herbert Hoover Dike (HHD) rehabilitation and considers completed or nearly completed Comprehensive Everglades Restoration Plan projects. LOSOM is intended to replace the current Lake Okeechobee Regulation Schedule, known as the 2008 LORS (LORS08).  

Florida Farm Bureau Concerns Revolve Around Four Topics: 

  1. The State’s ability to meet water supply needs under LOSOM 
  1. The unprecedented flexibility in LOSOM’s operation plan may cause impact outside of those identified through the NEPA process 
  1. The proposed plan’s modeling results produce EAA irrigation water demand volumes substantially less than volumes in the real-world data set 
  1. LOSOM does not include a water conservation or beneficial use zone above the Water Shortage Management (WSM) Zone that would reduce the risk of entering the WSM Zone. Clear and concise deference is not given to the SFWMD prior to water shortage 

The Corps has stated they will review comments, address concerns, update minor changes, and are very set on a Record of Decision scheduled on August 12, 2024. Florida Farm Bureau submitted comments that can be read here.  

FFBF Provides Comment for the Lower East Coast Water Supply Plan

June 2024 FloridAgriculture eNewsletter

The South Florida Water Management District (SFMWD) manages five different Water Supply Planning Regions throughout their 16-county geographic boundary. These water supply plans are updated every five years and were developed to assess and project water demands and potential sources of water through 20-year planning horizon. The plan updates are used by local governments, water users and utilities to update and modify local comprehensive plans, facility work plans and ordinances.

The Lower East Coast Water Supply Plan (LEC WSP) area includes Palm Beach, Broward, Miami-Dade and parts of Monroe, Collier, and Hendry counties. The South Florida Water Management District is developing the 2023-2024 Lower East Coast Water Supply Plan Update (2023-2024 LEC Plan Update) to assess projected water demands and potential sources of water for the period from 2021 to 2045.

The Lower East Coast Planning Area has a growing population and limited freshwater resources. Because freshwater resources are limited, the 2023-2024 LEC Plan Update focuses on other water supply sources, such as reverse osmosis to treat brackish groundwater, reclaimed water, storage options, seasonal surface water and water conservation to address future demands.

Florida Farm Bureau Federation remains very involved in all statewide Water Supply Plans, commenting regularly to ensure agriculture’s right to adequate water supply to stay in business. Comments on the LECWSP arose due to concerns over inadequate incorporation of the new Lake Okeechobee regulation schedule and its effect on agricultural water supply.

Below are the comments that were submitted to the LEC plan manager.

“On behalf of the Florida Farm Bureau Federation and our 132,000 member families, many of which live and farm within the boundaries of the Lower East Coast Water Supply Plan (LEC WSP) area, I appreciate the opportunity to comment on the Lower East Coast Water Supply Plan Update.

We have remaining concerns regarding how the upcoming Lake Okeechobee System Operating Manual (LOSOM) will be handled in the Water Supply Plan Update. Uncertainty remains on how to create and implement this plan without knowing what the lake schedule will be. The way that the schedule is described in the current LOSOM Water Control Plan does not provide the certainty and predictability needed for uniform and reliable operations. When we go back and review prior water supply plans, heavy reliance is placed on the lake regulation schedule, and with current LOSOM operations, and its inability to meet the lake’s MFL, we have no way of knowing how this will affect water supply.

Due to these concerns, we would like to request a delay in the plan process.

Florida Farm Bureau Federation greatly appreciates the District’s openness and willingness to listen to the concerns of our industry. We are thankful for the opportunity to provide these comments and look forward to continued collaboration.”

For more information, please contact the Florida Farm Bureau Federation Government and Community Affairs Division.