Lake Okeechobee has dropped below 13 feet above sea level. Will it drop low enough for new submerged aquatic vegetation to sprout?

Will a major storm cause the lake level to rise rapidly before vegetation has a chance to grow?

Time will tell.

On June 5, Lake O was 12.78 feet above sea level, more than a foot lower than the same date last year.

Evapotranspiration (a combination of evaporation and plant transpiration) continues to be the biggest draw from Lake O. For the week of May 27-June 2, evapotranspiration removed 46,730 acre feet from Lake O. Flow south for agricultural irrigation and urban water supply was 30,670 acre feet. Flow west to the Caloosahatchee River was 28,680 acre feet. The Caloosahatchee River depends on freshwater flow from Lake O when there is not sufficient local basin runoff to maintain optimal salinity levels in the estuary. There was no flow to the St. Lucie canal.

Inflows to Lake O were 19,910 acre feet in direct rainfall and 3,210 acre feet in surface flows, primarily from the Kissimmee River.

One acre foot is the amount of water needed to cover one acre of lane one foot deep. Lake Okeechobee’s surface is about 467,000 acre feet.

South of the lake, Water Conservation Areas 3-A and 2-A experienced heavy direct rainfall of 72,540 acre feet and inflows of 6,360 acre feet from the Everglades Agricultural Area (EAA) stormwater treatment areas (STAs).

Evapotranspiration removed 66,490 acre feet of water from the WCAs.

Outflows from the WCAs totaled 5,990 acre feet south under the Tamiami Trail to Everglades National Park and 720 acre feet east.

According to RECOVER, the lake’s normal ecological envelope ranges from 12 feet at the end of the dry season to 15 feet at the end of the wet season. The lake’s recovery envelope uses a low of 11.5 to 12.5 and a high of 14.5 to 15.5.

RECOVER (REstoration COordination & VERification) is a multi-agency team of scientists, modelers, planners and resource specialists who organize and apply scientific and technical information in ways that are essential in supporting the objectives of the Comprehensive Everglades Restoration Plan (CERP).

Lake Okeechobee needs seasonal lows for sunlight to reach the lake bottom to cause new submerged aquatic vegetation (SAV) to grow. Once new SAV has sprouted, it is also important that the lake does not rise faster than the plants can grow. The SAV is the lake’s natural filter system. It also provides habitat for fish and wildlife.

Lake Okeechobee’s level has been high since billions of gallons of water were pumped down the Kissimmee River from Orlando south after 2022’s Hurricane Ian. The lowest lake level in 2023 was 13.7 feet.

For most of the 2023-2024 dry season, the U.S. Army Corps of Engineers did not release water from Lake Okeechobee east to the St. Lucie and limited releases to the Caloosahatchee River to the beneficial freshwater flow the river needs to maintain optimal salinity levels in the estuary. Under the current regulation schedule for the lake, USACE could have released the equivalent of up to 2 feet of water on Lake O, but instead prioritized the health of the coastal estuaries. Releasing high volumes of freshwater changes the salinity levels in the estuaries.

At the time, Col. James Booth explained, while the lake schedule called for lake releases in order to give the lake ecology a chance to recover from several years of high water levels, the weather forecast indicated that even if they released water east and west they would not get the lake level low enough for a successful recovery year.