Spotlight on Lake O sediment study

The USACE Jacksonville District will execute a temporary, minor deviation to the Lake Okeechobee Regulation Schedule April 20 and 21 as part of the ongoing study by the South Florida Water Management District (SFWMD) and U.S. Geological Survey (USGS) to find ways to indirectly measure sediment and nutrients transported from the lake to the estuaries.

The deviation will allow up to 5,000 cubic feet per second (cfs) flow from structures for short periods of time for up to 8 hours on April 20 at the Moore Haven Lock and Dam (S-77) and April 21 at the Port Mayaca Lock and Dam (S-308).

USACE executed a similar deviation in February to support the same study and expects to do so again in May.

According to USACE, this study will help develop a better understanding of how different release schedules may influence nutrient/sediment loading to the estuaries.

“While the deviation allows for up 5,000 cfs releases in short bursts, it is expected that the flows will be closer to 500 cfs. Weather permitting, USACE will attempt to draw down the St. Lucie Canal (C-44) prior to the test to minimize the potential for opening the St. Lucie Lock and Dam (S-80),” they said.

“There is still a possibility that the S-80 may be opened to accommodate the increased water resulting from the testing or to maintain canal levels from local runoff in the case of heavy rains in the basin.”

The maximum effect of these releases on Lake Okeechobee stage is less than ½ inch.