Posted on April 2, 2019
Lake Okeechobee discharges have stopped to the St. Lucie River and been reduced to the Caloosahatchee River, but the Army Corps of Engineers hasn’t ruled out the possibility of restarting and increasing them.
Discharges to the St. Lucie River stopped Saturday and were reduced to the Caloosahatchee River to a daily average of about 650 million gallons a day, according to a Corps news release issued Monday.
During dry periods, the Caloosahatchee needs about that much flow from Lake O to hold back saltwater intrusion in the river’s estuary near Fort Myers. The St. Lucie, on the other hand, never needs water from the lake.
Discharges stopped
Nearly 8 billion gallons of Lake O water has entered the St. Lucie River estuary since the discharges began Feb. 23, according to Corps data compiled by TCPalm.
That much water would cover the city of Stuart with about 4 feet, 3 inches.
About 11.6 million gallons of lake water entered the estuary Saturday before the gates at the St. Lucie Lock and Dam were shut, the data shows.
On Sunday, gates at both the St. Lucie and the Port Mayaca Lock and Dam were closed.
“The Corps will continue to monitor conditions and adjust flows as necessary,” the news release issued Monday stated.
Lower lake level
The Corps usually tries to bring the lake elevation down to 12 feet, 6 inches during the winter and spring dry season. But this year, the Corps — at U.S. Rep. Brian Mast’s urging — wanted to lower the lake level to help prevent the need for massive summer discharges that can cause toxic algae blooms.
The lake elevation Monday morning was 11 feet, 10 ? inches.
“We’ve been successful in lowering the lake this year, which should help regenerate some of the submerged aquatic vegetation, make it easier to do controlled burns and may help reduce releases during the hot summer months when algae is most likely to bloom,” said Corps Lt. Col. Jennifer Reynolds, deputy commander for South Florida.
The discharges east and west, plus drier conditions and windy weather that increased evaporation off the lake surface, caused the lake to drop more than three-quarters of a foot within the past month, Reynolds said.
“As a result, we have adjusted the flows to the St. Lucie down to zero this week,” she said.
No significant damage
Lake O discharges don’t appear to have caused any significant environmental damage in the St. Lucie River. No algae blooms have been reported in the river during the discharges.
On Thursday, the Florida Oceanographic Society in Stuart gave water quality in the river and the Martin County section of the
Indian River Lagoon an overall “B,” or good grade.
The South Fork of the river, where the Lake O water enters through the St. Lucie Lock and Dam, earned a “D,” or poor grade, mostly because of low salinity. The middle section of the river along the downtown Stuart waterfront, home to most of the estuary’s oyster beds, earned a “C” or satisfactory grade.
Salinity in the middle section of the river should be more than 20 parts per thousand; Florida Oceanographic reported salinity as of Thursday was 18 parts per thousand. Oysters can die when salinity is less than 10 parts per thousand for 28 days or more.
Source: tcpalm.com
