Lake Okeechobee continues to rise, primarily from direct rainfall into the big lake. Heavy rainfall is also impacting the Caloosahatchee River, the St. Lucie canal, the St. Lucie Estuary, the C-44 reservoir and the stormwater treatment areas (STAs) and water conservation areas (WCAs) south of Lake Okeechobee.

In a Sept. 13 media briefing, Major Cory Bell, Deputy Commander of the U.S. Army Corps of Engineers Jacksonville District, said Lake Okeechobee’s level was at 14.78 feet above sea level, about 5 inches higher than the previous week and about 10 inches higher than 30 days ago.

According to the South Florida Water Management District data, for the seven day period Sept. 2-8, the lake received 70,510 acre feet in direct rainfall and 59,800 acre feet in surface water inflows.

No lake water was released east, west or south in the past week, Bell said, as all areas are already full from local rainfall.

The seven-day average flow at the W.P. Franklin Lock was 5,797 cubic feet per second (cfs), all from local basin runoff. The flow target at the W.P. Franklin Lock remains at 2,000 cfs. If local basin runoff meets or exceeds that target, no lake water is released at the Julian Keen Jr. Lock, where the lake connects to the Caloosahatchee River. The Sept. 12 flow at the Franklin Lock was more than 9,000 cfs.

More heavy rainfall is anticipated. “We’re coming up on the peak hurricane levels,” said Bell.

East of Lake O, while no lake water was released to the C-44 canal (St. Lucie canal) at Port Mayaca, flow through the St. Lucie Lock averaged 1,368 cfs, all due to local basin runoff. Bell said earlier in the wet season, they were able to prevent flows at the St. Lucie Lock by pumping excess basin runoff into the C-44 reservoir. However, the reservoir is now near capacity. In late August, they started releasing some water from the reservoir (averaging below 300 cfs) through a stormwater treatment area (STA) and back into the C-44 canal. However, due to recent rainfall in the basin, they stopped these releases.

“The weather has not cooperated,” said Bell. The above-ground reservoir is currently 9.6 feet deep and has a capacity of holding water up to 10 feet deep. The reservoir was originally designed to hold water up to 15 feet deep, but testing found there were some seepage concerns when the structure was filled past 10 feet. While USACE work on solutions to prevent the seepage problem, they are keeping the reservoir no higher than 10 feet. Bell said if direct rainfall into the reservoir pushes the level above 10 feet, they will have to release water through the STA to the C-44 canal and manage canal levels but releasing water through the St. Lucie Lock.

The C-44 canal is managed between 14 feet and 14.5 feet above sea level for navigation, flood control and water supply. If Lake Okeechobee is below 14 feet, excess basin runoff can be released into the lake. Flow at the Port Mayaca Lock is gravity-fed. When the lake is above 14 feet, the only option is to release excess local basin runoff through the St. Lucie Lock.

Bell said USACE will hold an informational meeting to address comments from stakeholders and the public regarding USACE and SFWMD development of the Central Everglades Planning Project (CEPP), Everglades Agricultural Area (EAA), A-2 Stormwater Treatment Area (STA) Operational Plan on Oct. 4, from 11 a.m. to noon at https://usace1.webex.com/meet/nicolette.c.iatropoulos.

Interested participants can also call into the meeting at 1-669-234-1177 or 1-844-800-2712 (toll free), Access Code: 2819 739 1511.