Natural Resource Analysis of Lake Okeechobee, Florida

Client: South Florida Water Management District
Location: Central Florida

Lake Okeechobee, located in central Florida, serves as a multiple-use resource that supports valuable commercial fisheries, provides flood control, and acts as a reservoir for both potable and irrigation waters for much of south Florida. The South Florida Water Management District retained Hazen and Sawyer to conduct an analysis of phosphorus control strategies north of Lake Okeechobee. The goal was to provide a benefit-cost analysis of new phosphorus control alternatives (PCAs) to further reduce phosphorus loads entering the lake.

Project Outcomes and Benefits

  • Study developed 10 PCAs and identified benefits and costs of each PCA using a full-cost accounting approach, attempting to identify and quantify the social benefits and costs resulting from a policy decision.
  • A computerized alternatives evaluation/full-cost accounting model was developed during this study, which allowed for updating as new data and information became available.
  • A desktop evaluation of alternative nutrient reduction technologies for Lake Okeechobee was completed and two additional PCAs were evaluated.

Lake Okeechobee suffers from excessive phosphorus loading that has contributed to a serious decline in lake and downstream water quality, affecting most flora and fauna communities, and causing substantial blue-green algae blooms during the mid-1980s. (Photo Courtesy of South Florida Water Management District)

Land use activities and hydrologic changes contribute phosphorus loads to the Lake. About one-third of the land is improved pasture and another one-third is unimproved pasture, rangeland and upland forest.

This study developed 10 PCAs and 18 PCA combinations that included on-farm BMPs and regional technologies reduce phosphorus loads to Lake Okeechobee. An example of an on-farm PCA is PCA 4 which is an improvement to the existing Dairy Rule design on dairy facilities north of Lake Okeechobee. This PCA ranked well in the evaluation.

Another on-farm PCA is number 5 which is a combination of enhanced cow-calf best management practices that were developed from the existing literature. This PCA ranked well in the evaluation. (Photo courtesy of USDA Natural Resources Conservation Service)

An example of a regional PCA is PCA 7 which is a Reservoir-Assisted Stormwater Treatment Area. This type of system is a potential regional solution to managing phosphorus loads to the Lake. This PCA ranked well in the evaluation. (Photo Courtesy of the South Florida Water Management District)

This study identified benefits and costs of PCAs or PCA combinations using a full-cost accounting approach.

Full-cost accounting attempts to identify and quantify the social benefits and costs resulting from a policy decision. In this study, 10 evaluation criteria were developed. Decades of research into phosphorus reduction strategies in the Lake Okeechobee Basin and the Everglades Agricultural Area and many research and planning projects provided a wealth of data available for use in the economic evaluation of alternatives. The evaluation model uses the evaluation criteria to measure the relative benefits and costs of alternatives and ranks alternatives based on the magnitude of itemized benefits and costs.

A computerized alternatives evaluation/full-cost accounting model was developed during this study, which allowed for the evaluation and ranking of PCAs and PCA combinations. The results can easily be updated as new data and information become available. The computerized model allowed the District to add and evaluate additional PCAs.

This Full-Cost Accounting Evaluation Model allowed the organization of all available data in reducing P loads to Lake Okeechobee. This model provided a structured approach to (1) achieving an apples-to-apples comparison of P-control methods, (2) identifying information gaps, and (3) providing input to the development of the Lake Okeechobee Protection Plan. By far, the highest ranked combination of alternatives consisted of the RASTAs with Dairy Farm Optimization and Enhanced Cow-Calf BMPs. In addition, the model results indicated that a combination of regional and on-farm PCAs provides higher net benefits than the individual PCAs alone.

The results of this project were used by the District to develop the implementation plan to meet the phosphorus Total Maximum Daily Load (TMDL) for Lake Okeechobee. This study was published in the Florida Water Resources Journal (June 2004) and presented at numerous conferences.

For more information on this project, or to discuss a similar project in your area, contact

Grace M. Johns, Ph.D. at gjohns@hazenandsawyer.com