OKEECHOBEE — Lake Okeechobee continued to hover just below 14 feet above sea level last week.
With the exception of six weeks in February and March, flow from the lake to the Caloosahatchee River has been done to benefit the river and the salinity levels in the Caloosahatchee estuaries. If there was sufficient flow from local basin runoff into the river to keep the estuaries at the optimal salinity, no lake water was released. Generally flows below 450 cfs are considered too low and flows about 2,800 cfs are considered too high to maintain the healthy salinity levels For the seven days prior to Sept. 16, flow at the Moore Haven lock averages 352 cfs. Flow at the Franklin Lock averaged 730 cfs.
There has been no flow from the lake to the St. Lucie Canal since March 30. Since the start of the wet season, flow at Port Mayaca to the St. Lucie Canal was limited to six weeks in February and March conducted to lower Lake Okeechobee in an effort to bring the lake level down before the start of the wet season. For much of the wet season, water backflowed from the St. Lucie canal into the lake. The corps tries to maintain the St. Lucie Canal at 14 feet to 14.5 feet above sea level. If the water level in the canal is higher than the water level in the lake, if the Port Mayaca gates are open, the water from the canal backflows into the lake.
For the seven-day period prior to Sept. 16, there was no outflow south from the lake. Rainfall south of the lake continued to fill up the water conservation areas south of the lake, leaving no capacity to accept additional water flow from the lake, despite some releases from the WCAs south under the Tamiami Trail.
Year round, water leaves the lake through percolation into the aquifer and evaporation into the air. This is why the lake level stayed fairly constant despite an average inflow of 3,087 cfs and average outflow of only 352 cfs. One week ago, the lake level was 13.86 feet above sea level; On Sept. 16, the level was 13.89 feet.
While there was no outflow south from the lake to the WCAs south of the Everglades Agricultural Area for the past week, there was outflow south earlier in the month.