Lake Okeechobee continues to recede. On April 9, the Big O was 12.34 inches above sea level, according to the U.S. Army Corps of Engineers (USACE).

Lake O is in “recovery mode” in the Lake Okeechobee System Operating Manual (LOSOM) schedule. Water managers are attempting to bring the lake below 12 feet for 90 days or below 11 feet for 60 days. The lower lake levels will allow sunlight to reach the lake bottom, and new submerged aquatic vegetation (SAV) to grow. SAV is the lake’s natural filter and provides critical habitat for fish.

Hurricanes and multiple years of high water levels have destroyed the lake’s SAV.

In recovery mode, USACE is sending the “maximum practicable” flow of lake water south.  Flow south is restricted by the Tamiami Trail, which acts as a dam across the Everglades. Florida Department of Transportation (FDOT) is working to raise portions of the trail and allow more  flow under the road to Everglades National Park and Florida Bay. The FDOT project is two years behind schedule and now projected to be complete in 2026.

During the seven-day period March 31-April 6, direct rainfall into the lake totaled 11,300 acre feet of water. Surface water inflows from the north (Kissimmee River and Fisheating Creek) totaled 4,730 acre feet. Backflow into the lake from the C-44 canal (St. Lucie Canal) totaled 430 acre feet.

The Caloosahatchee River needs some freshwater flow from the lake during the dry season to maintain optimal salinity levels in the estuary. USACE has set the target flow at 1,400 cubic feet per second (cfs) measured at the W.P. Franklin Lock, which is more than 43 miles from Moore Haven, where lake water enters the river through the Julian Keen Jr. Lock.

Outflow to the Caloosahatchee for the seven-day period was 20,080 acre feet. Flow south for water supply for urban, agricultural and environmental use was 28,550 acre feet. As normal in the dry season, most of the water leaving the lake was via evapotranspiration (a combination of evaporation and plant transpiration), which removed 42,070 acre feet of water from the Big O.

The lake dropped 0.18 feet (2.16 inches) in the seven-day period.

South of the lake, the water conservation areas (WCAs) received 10,740 acre feet of direct rainfall and 7,520 acre feet of flow from the lake. Evapotranspiration removed 64,460 acre feet from the WCAs.

USACE stopped releasing water from the lake to the St. Lucie Canal in March. According to South Florida Water Management District (SFWMD) biologists, low salinity levels caused by freshwater releases in the brackish water of the estuary could have hurt oyster spawning season. The St. Lucie Estuary continues to receive freshwater flow from local basin runoff.

Salinity levels are rising in the St. Lucie Estuary. According to the April 9 SFWMD Environmental Conditions Report, salinity in the middle estuary was in the optimal range (10-25 parts per thousand or ppt) for eastern oysters.

Salinity levels in the Caloosahatchee Estuary were in the optimal range for tape grass (0-10 ppt) in the upper estuary. Salinities were within the optimal range (10-25 ppt) for oysters at Cape Coral and Shell point and in the upper stressed range (above 25 ppt) at Sanibel. (For comparison, the average salinity of ocean water is between 34 and 36 ppt.)

Florida Bay salinity was 31.5 ppt, and increase of 0.6 from the previous week.