Lake Okeechobee Operations by Means of the Water Supply and Environment (WSE) Regulation Schedule

Abstract

Lake Okeechobee is the second largest freshwater lake in the conterminous United States of America and is the heart of the water resources system in south Florida. The Herbert Hoover dike and several water control structures allow management of the Lake to meet different objectives, including flood control, water supply, and environmental enhancement. The regulation of the Lake water levels is performed by the U.S. Army Corps of Engineers (USACE) in consultation with the South Florida Water Management District (SFWMD). Flood control releases from Lake Okeechobee are made through the Caloosahatchee River, through the St. Lucie Canal, and southward to the Everglades. Since the early part of the 20 th century and until the middle of 2000, the Lake was operated using a variety of calendar-based regulation schedules. During the 1990's, the SFWMD and USACE conducted a study to develop and implement a more robust regulation schedule. The Water Supply and Environment (WSE) regulation schedule for Lake Okeechobee was created and it became the official operating schedule in July of 2000. Several innovative factors are introduced in WSE: Use of decision trees to guide water managers, use of indicators for current meteorological and hydrologic conditions, inclusion of seasonal and multi-seasonal hydrologic forecasting (outlooks) in the decision trees, consideration of ecological, and environmental conditions along and downstream of the release canals or rivers, etc. While still being essentially a flood release schedule, WSE was designed to improve the balance of the multiple Lake management objectives. This paper describes WSE and its weekly implementation effort. The different components and elements of WSE are presented, with the climatic and hydrologic data used in the process. Methods used to produce hydrologic outlooks are described. Additionally, the last six years of Lake Okeechobee operations under WSE are discussed. Some of the problems encountered and temporary solutions are presented.