MOORE HAVEN — The U.S. Army Corps of Engineers has increased flow from Lake Okeechobee to the Caloosahatchee River. On May 18, the corps increased flow to the Caloosahatchee estuary, as measured at the Franklin Lock, from 600 cubic feet per second to 800 cfs. Lake water enters the lake at Moore Haven.
Direct rainfall into the Caloosahatchee River basin could result in flow about 800 cfs at the Franklin Lock.
The Franklin Lock is 43.4 miles from the Moore Haven lock, so the water flowing through the Franklin Lock is a mixture of lake water and basin runoff that flows directly into the river.
This means that some days, most or even all of the flow through the Franklin Lock is local basin runoff. For example, one day last week there was no water released through the Moore Haven Lock and flow at the Franklin Lock was above 1,000 cfs, due to rainfall in the basin.
The current lake releases are designed to help the Caloosahatchee River by preventing saltwater intrusion and maintaining optimal salinity levels in the Caloosahatchee estuary.
The South Florida Water Management District has guaranteed the Caloosahatchee a minimum 400 cfs dry season flow; Lee County officials have asked for 700-800 cfs and, in a lawsuit filed last year, stated that the optimum flow at the Franklin Lock is 1,000 cfs.
Through most of the dry season, the corps has given the Caloosahatchee the 1,000 cfs, requested by Lee County officials to help the estuary’s ecology recover from the effects of damage from the storms in recent years.
During part of February and the month of March, the flow was increased slightly in an effort to lower Lake Okeechobee. During the period, the flow was higher than the desired 1,000 cfs, salinity levels in the estuary were monitored to ensure the extra freshwater did not harm the estuary’s ecology.
• From May 4 through May 17, flow to the Caloosahatchee was 600 cfs.
• From April 20 to May 3, flow to the Caloosahatchee was 800 cfs.
• From March 30 to April 20, flow to the Caloosahatchee was 1,000 cfs.
• From March 23 to March 29, flow to the Caloosahatchee was 1,400 cfs.
• From Feb. 23 to March 22, flow to the Caloosahatchee was 1,800 cfs.
• From Jan, 31 to Feb. 23, flow to Caloosahatchee was 1,000 cfs.
• From Jan. 25 to Jan. 30, flow to the Caloosahatchee was 700 cfs.
• From Jan. 11 to Jan. 25, flow to the Caloosahatchee was 850 cfs.
The St. Lucie Canal east of Lake Okeechobee received no lake releases for most of the dry season. No lake water was released at Port Mayaca during the period from Oct. 4, 2018, to Feb. 23, 2019. No lake water has been released at Port Mayaca since March 30. Flows to the St. Lucie Canal are measured at the St. Lucie Lock, which is 23.9 miles from Port Mayaca. Some flow measured at the St. Lucie Lock is from local basin runoff that drains into the St. Lucie Canal.
From March 16 to March 30, flow to St. Lucie, measured at the St. Lucie Lock was 250 cfs.
From Feb. 23 to March 15, flow to the St. Lucie was 500 cfs.
Tuesday’s lake stage was 11.21 feet NGVD.
The corps will continue to monitor conditions and adjust flows as necessary. Any changes in flows to the estuaries will be announced to the public.