JACKSONVILLE – The U.S. Army Corps of Engineers will stop releasing water from Lake Okeechobee to the St. Lucie River on Saturday, Jan. 9. Flows to the Caloosahatchee River will be at the level that is beneficial for the salinity of the estuaries.
In a media conference call on Jan. 7, Col. Andrew Kelly, commander of the Jacksonville District U.S. Army Corps of Engineers, said Lake Okeechobee is a little over 2.5 feet higher than last year, about 4 inches lower than it was a month ago.
He said the corps will take a break from releases to the coastal estuaries while they work on a more formalized plan for the rest of the dry season.
Kelly said if there is rainfall in the basin, some water may be released through the St. Lucie lock, but it won’t be water from Lake Okeechobee. Lake Okeechobee connects with the St. Lucie Canal at Port Mayaca, which is 23.9 miles from the St. Lucie Lock. If there is rainfall in the local basin, runoff that drains into that 23.9 miles of canal will be released through the St. Lucie Lock. Over the past seven day period, flow at Port Mayaca averaged 784 cfs.
Lake Okeechobee connects with the Caloosahatchee River at Moore Haven. The target flow will be measured at the Franklin Lock which is 43.4 miles from Moore Haven. Flow through the Franklin Lock is a mixture of lake water and local basin runoff. Kelly said the corps will work with the South Florida Water Management District and stakeholders so the flow at the Frankiin Lock will be targeted somewhere between 650 cubic feet per second (cfs) – the minimum flow required to prevent damage to the estuaries from high salinity – to 1,000 cfs, which is considered the most beneficial flow for the estuaries. Flows above 2,600 cfs may be damaging to the Caloosahatchee estuaries.
Over the past seven day period, flow at Moore Haven averaged 567 cfs. Flow at the Franklin Lock averaged 1,101 cfs.
Kelly said the lake level, which was 15.74 on Jan. 7, is showing a recession that is pretty average for the January/February time frame. With no additional lake releases to the coastal estuaries the analysis shows the lake would be in the vicinity of 14 feet at the end of the dry season, “still higher than we want to see,” Kelly explained.
“At the beginning of February, the corps will formalize the full-on dry season schedule once we understand a little bit better if there will be a lower than average rainfall expected,” he said. December brought normal rainfall.
South of the lake, some flow has opened up but the stormwater treatment areas (STAs) are full and the water conservation areas (WCAs) south of the lake are 1-2 feet above normal, he said. There is some flow south for water use, “but we are not pushing lake water to the STAs and WCAs now because it’s still wet.”
Kelly said the red tide reported near Sanibel was not a factor in the decision to reduce the lake releases as this plan was already in place before the red tide was reported. He said the releases to the Caloosahatchee will be driven by the freshwater flow the environment needs to keep those estuaries healthy.
“If we go to 1,000 cfs, its because the estuary scientists are actually requesting it,” he explained. The baseline minimum flow is 650s.
“It’s pretty normal for the Caloosahatchee to ask for 1,000 to keep the salinities in the right places,” Kelly said.
Some water from the WCAs is moving south under the Tamiami Trail. Flow under the Tamiami Trail was about 4,600 cfs on Jan. 7
“The good news when you look at this year, the water delivery to Shark River Slough are at a record 1.5 million acre feet,” said Kelly. “The effects of (Tropical Storm) Eta and the volumes of precipitation certainly led to that and our efforts helped as well.”
Another bit of positive news: “I don’t think we are going to have any problems with water supply this year.”
Kelly outlined several factors that will be taken into consideration when developing the dry season plan:
• “We’re going to look at where the lake ought to be at the beginning of the wet season. 14 feet is uncomfortable. It’s not a good place to be on June 1. We’d like to see it lower than that.
• “Then we look at how much water is available to move south. The ability to push water from the lake south will be a key consideration.
• “We’re going to look at the ecology of the lake and the estuaries and be mindful at where they are ... We will maximize the water we can release to the estuaries and keep them in the good salinity range.
• “The algae picture – right now everything is looking really good. High lake levels especially going into the heat of the summer potentially lead to algae that could be higher than normal.”
Kelly warned the corps might have to release more water east and west before the start of the wet season.
“We are open to the fact we may have to be a little more aggressive in pushing water anywhere we can” in order to get the lake lower,” he said. “We will react to what Mother Nature delivers.”
Kelly said even though the high water levels are not good for the submerged aquatic vegetation (SAV) the consensus is the SAV was doing well because the lake was at a good to relatively lower level in 2019.
“We were able to bounce back from Irma,” he said, adding they believe the SAV was strong enough to absorb the rise in the lake over the wet season.
Kelly said work on the design of the Everglades Agricultural Area (EAA) reservoir continues. “We were encouraged to see the language coming out of the WRDA (Water Resources Development Act) bill.” The WRDA was approved as part of the end of the year “omnibus” funding bill.
“Once we see the budget numbers, we are well postured to continue to move forward and expedite the EAA reservoir construction,” said Kelly.