Lake Okeechobee discharges to St. Lucie, Caloosahatchee likely will begin next week

Ed Killer
Treasure Coast Newspapers

Lake Okeechobee discharges to the St. Lucie River likely will begin next week.

Discharges will start "beginning Tuesday or Wednesday," Col. Andrew Kelly, the Army Corps of Engineers' Florida commander, announced in a news conference call Friday.

The rate likely will be 1.16 billion gallons a day east to the St. Lucie River and 2.59 billion gallons a day west to the Caloosahatchee River, but Kelly said he will announce the exact rate in a news conference call Monday or Tuesday.

The Corps is authorized to release those amounts, and even more if needed, according to the operational rules that govern the agency's lake management.

The Corps will try to keep the discharge period as short as possible, but it will depend on the weather, Kelly said. The discharges could last a month or more, he estimated.

Lake Okeechobee stands at 13.5 feet Friday, Aug. 7, 2020, at Lock 7, Jaycee Park in Okeechobee. According to the Lake Okeechobee Regulation Schedule (LORS) 2008, the U.S. Army Corps  of Engineers attempts to keep the lake level between 12.5 feet and 15.5 feet above sea level during the wet/hurricane season June 1 through Nov. 30, and the large, freshwater lake has risen about a foot since early July.

Lake Okeechobee

Lake O's elevation was 16.02 feet above sea level Friday. How fast the lake is rising, however, concerns the Corps more than its elevation, Kelly said.

Between Oct. 1 and Oct. 8, Lake O rose 6 inches, a result of an overactive middle of the rainy season, which ends unofficially Nov. 30. The lake posted these levels through 2020 (all amounts are measured in feet above sea level):

  • 11 on May 17, it's lowest level this calendar year
  • 11.47 on June 1
  • 12.28 on July 1
  • 13.31 on Aug. 1
  • 14.37 on Sept. 1
  • 15.56 on, Oct. 1
  • 16.02, Oct. 8

"We have got to get water off the lake and stem the rise of the water," Kelly said. "As soon as we turn the corner, we can change the discharge rate. Until then, we will release water off the lake and do it in as short of amount of time as possible."

If discharges become necessary, they'll be big, Kelly warned Oct. 2.

"If the time comes that we have to pull the trigger," Kelly said, "we'll likely be in a position that we have to get as much water off the lake as quickly as possible, so we'll release as much water as we can."

Dodged bullet?

Since Sept. 18, the Corps has been warning the Treasure Coast about the possibility of discharges and for three consecutive weeks has postponed them.

"Over the last 30 days, we've seen the lake rise about a foot and a half," Kelly said Friday, noting the 30-day rolling average for lake level rise had been 1 foot, but increased to 1.25 feet in September. "We're trending in the wrong direction. The lake is rising faster, increasing its rate of rise."

Waters north of Lake O in the Kissimmee River and Chain of Lakes basin are all "over schedule," Kelly said. The Corps has exhausted all measures to move water south into water conservation areas and stormwater treatment areas, he said.

"Everything is very wet," he said. "As the basin to the south gets more saturated, you basically just run out of room."

Lake O has so little cyanobacteria, commonly called blue-green algae, that Kelly said he's not worried about it being carried into the rivers and causing a bloom.

Greek letters

Nearly 554 billion gallons of water, or 1.7 million acre feet, flowed into Lake O in September.

The first week of October already has produced half the typical rainfall amount for the month, according to the South Florida Water Management District conditions report from its Oct. 8 board meeting. 

Between Oct. 2 and Oct. 8, the Kissimmee Chain of Lakes received 2.41 inches of rain or about 338% of the normal average rainfall for the first week of October.

All that water is making its way south toward Lake O, Kelly said. Inflows exceeded 7 billion gallons per day on Oct. 9. Water can enter Lake O six times faster than it can leave the lake, the Corps previously has said.

The end of the hurricane season cannot come soon enough, Kelly said.

"After we turn the corner, and we're not using anymore Greek letters for the hurricane season, and we can get to a place where the next storm will not cause a problem, we can declare victory," he said.

Wet season woes

The Corps hasn't discharged Lake O water to the St. Lucie since March 2019 and the river has not had an algae blooms since discharges in summer 2018.

In Iate August, the Corps began sending stormwater runoff — mostly from farmland in western Martin County — from the C-44 Canal through the St. Lucie Lock and Dam gates and into the river. 

Over the past two weeks, flows have averaged about 244 million gallons a day, and the Corps could more than quadruple that soon.

Since July, the Corps reports 8.8 billion gallons of water has poured from the C-44 Canal into the St. Lucie River. None of the water was from Lake O, Corps spokesperson Jim Yocum wrote in an email. 

More:Ed Killer: 4 reasons why impending discharges are unnecessary

That water tends to be high in fertilizer, whose nitrogen and phosphorus can feed algae blooms in both the lake and the St. Lucie River estuary. Even fertilizer-free freshwater, in large amounts, can cause harm by lowering salinity in the estuary's brackish water, threatening the oysters and seagrass that form the backbone of the ecosystem.

Salinity already is low because of frequent summer rain and record rainfall last weekend. Additionally, the canals that feed into the St. Lucie River have been pouring runoff into the river throughout the rainy periods.

According to data provided by the South Florida Water Management District, 105.3 billion gallons of water has dumped through the spillways at C-23, C-24 and through the gates at Gordy Road at Ten Mile Creek, the headwaters of the St. Lucie River's North Fork. An additional, 30 billion gallons of runoff has entered the Indian River Lagoon at the C-25 spillway in Fort Pierce. 

Here is how each spillway breaks down by total gallons of runoff entering Treasure Coast waterways, Jan. 1 through Oct. 8, 2020:

  • C-24 — 38.7 billion
  • C-23 — 38.3 billion
  • Ten Mile Creek — 28.2 billion
  • C-25 (into IRL) — 30.9 billion
  • Total into St. Lucie River — 105.3 billion

King tides

What effect next week's king tides will have remains to be seen, Kelly said.

Higher than usual high tides are expected to befall South Florida, including Martin County, from Oct. 15-20 and from Nov. 14-17, according to various meteorological sources. These are expected to be even stronger than those that occurred in mid-September, and could measure as much as 4 feet above mean low water.

In September, parts of neighborhoods along the South Fork of the St. Lucie River experienced minor flooding. 

"We've got to look at everything; it's part of the factor in our decisions, for sure," Kelly said of king tides. "But we have to slow the rate of rise. We’ll take a look at everything, but I don’t see any ability to do anything about it. If we discharge less than the scheduled rate, it just won't do much to help us with the lake."

Ed Killer is TCPalm's outdoors writer. Become a valued customer by subscribing to TCPalm. To interact with Ed, friend him on Facebook at Ed Killer, follow him on Twitter @tcpalmekiller or email him at ed.killer@tcpalm.com.