Understanding the ups and downs: application of hydrologic restoration measures for a large subtropical lake

Abstract

Julian P II, Welch Z. 2022. Understanding the ups and downs: application of hydrologic restoration measures for a large subtropical lake. Lake Reserv Manage. 38:304–317.

Hydrologic regimes in shallow lakes strongly influence the system’s function and ecology. Changes in water levels can have nonlinear, disproportionate effects in these low-gradient systems. High water levels can submerge upper elevation littoral areas, degrade benthic habitats, and redistribute sediments and nutrients throughout the lake. When water levels are low, wetland littoral areas are dried out, prompting shifts in plant communities. Lake Okeechobee, a large shallow lake, is a diverse and complex ecosystem managed for multiple purposes. Currently, water levels within the lake are managed based on the Lake Okeechobee Regulation Schedule of 2008, which is being replaced as restoration projects now are complete. The new regulation schedule, Lake Okeechobee System Operating Manual (LOSOM), updates water management rules while attempting to balance the needs of downstream systems; salinity and water quality in the Caloosahatchee and Saint Lucie estuaries; and more water for the southern Everglades. This study evaluates LOSOM relative to ecologically significant performance measures for the lake. Overall, the proposed regulation schedule is expected to cause deeper average lake levels, increased occurrence of damaging high-stage events, and reduced frequency of low-stage events. While decreases in the severity and frequency of low stages will be beneficial, increases in high stages may affect the long-term ecology of the system. As lake management shifts to optimize restoration efforts around and downstream of Lake Okeechobee, restoration projects upstream of the lake become critical to building and improving resilience in this central South Florida ecosystem.

Keywords:

• Everglades
• hydroecology
• lake management
• water level
• water management

Acknowledgments

The authors thank the US Army Corps of Engineers and the South Florida Water Management District for providing modeling output. The authors also thank Leah Reidenbach, Paul Gray, Alan Steinman, Tom James, and anonymous peer reviewer(s) and editor(s) for their efforts and constructive review of this article. We dedicate this article to Dr. Karl Havens, who was an advocate for Lake Okeechobee, an amazing scientist, and an inspiration to everyone he worked with. This research was conducted on lands and waters that have been cared for by innumerable generations of original peoples of the past, whose memory we honor.

Conflict of interest statement

The authors declare that they have no conflict of interest.