Posted on June 22, 2022
The U.S. Army Corps of Engineers (USACE) Jacksonville District plans to execute a minor deviation June 22 that will release water from the lake as part of an ongoing sediment study by the South Florida Water Management District (SFWMD) and the U.S. Geological Survey (USGS).
The releases will affect only the Julian Keen, Jr. Lock and Dam (S-77) as water is released to support the study.
The initial releases are planned for the morning of June 22 at S-77 and are expected to last for a maximum of four hours of flows not to exceed 2,000 cubic feet per second, followed by additional flows in the afternoon, not to exceed 2,600 cfs for a maximum of four hours.
The purpose of study is to better understand nutrient and sediment transport to the estuaries under different flow conditions. USACE executed similar deviations in 2021 to support the same study.
During the collection period, the S-77 is required to be open to take sediment measurements. This deviation allows the USACE to open S-77 for a relatively short period of time, even though flows at S-79 will be above the flow target of 1,000 cubic feet per second.
The estimated total volume for the releases is 1,500 acre-feet, which is the equivalent of 0.003 feet, less than a tenth of an inch on the lake
No downstream impacts are expected in the Caloosahatchee River Estuary due to the short duration of the study.
This important research will help understand the relationship between suspended sediment concentrations, how they originate, how they carry nutrients, and how that might impact algal bloom development and growth.
USACE will monitor conditions and work with USGS and SFWMD to adjust flows for these studies as necessary if conditions on the lake or in the estuaries change.