Corps working on new lake schedule

Posted 3/23/21

Plans for the future of Lake Okeechobee were discussed during the Lake Okeechobee System Operation Manual (LOSOM) Project Delivery Team (PDT) Zoom meeting on Monday, March 22.

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Corps working on new lake schedule


Plans for the future of Lake Okeechobee were discussed during the Lake Okeechobee System Operation Manual (LOSOM) Project Delivery Team (PDT) Zoom meeting on Monday, March 22.

“We kicked this thing off early,” explained Col. Andrew Kelly, commander of the U.S. Army Corps of Engineers Jacksonville District. “We wanted to take our time and do it right.”

He said the online meetings, which were initially driven to that format last year by the pandemic, resulted in more public participation in the process than ever before.

The LOSOM schedule will likely be used for years, he explained. The corps is trying to build enough flexibility into LOSOM to make changes as needed when new Comprehensive Everglades Restoration Plan (CERP) projects come online.

The new schedule will also include algae science and updated information on water needs, he explained.

“We’ve got to take a look at some of the trade offs,” Kelly said.

He said the LOSOM look for balance, and “do what is best for the lake and all of the different components that are sometimes at odds.”

LOSOM will replace the Lake Okeechobee Regulation Schedule (LORS) which was put in place in 2008.

“This is different than LORS because things are going to get better,” said South Florida Water Management District (SFWMD) Executive Director Drew Bartlett. He said the improvements to the Herbert Hoover Dike, the C-43 and C-44 reservoirs and the Everglades Agricultural Area stormwater treatment area (STA) and reservoir all provide more options for water storage.

Jessica Mallet, engineering lead for LOSOM, said a lot of simulations were conducted using conceptual lake schedule plans.

For iteration 1, modeling on a variety of plans was conducted using 52 years of rainfall data.

The goal is to incorporate flexibility in Lake Okeechobee Operations while balancing Congressionally authorized projects, she explained. Objectives include managing risk to public health and safety, life and property, meeting authorized purposes for navigation, recreation and water supply, and improve the ecology of Lake Okeechobee, the estuaries and the Everglades.

Two of the plans were requested by Congress. One plan included no lake releases to the C-44 canal (St. Lucie canal). Another plan limited flow from the lake at Moore Haven to the beneficial flow the Caloosahatchee River needs in the dry season. Other plans considered were proposed by Audubon, the lake area communities and the Everglades Foundation. The Lake Okeechobee Ecology Plan is close to current schedule, which tries to keep the lake between 12.5 feet and 15.5 feet. Water supply and navigation plans were about a foot higher than other plans during drought periods

“We are looking to finish the rehabilitation of Herbert Hoover Dike in 2022. That gives us the opportunity to manage the lake in a different manner,” Mallet explained. “Everything should be finished in 2022.

“Even with improvements to the dike, we still have to consider dam safety while we are evaluating regulation schedules for Lake Okeechobee,” Mallet said. A new dam safety metric was developed for use when the repairs are complete.

Dam safety is a corner stone for “go or no go” for the alternatives, she said. “Even with the rehab there is residual risk and we need to manage the risk,” said Millet.

“Any alternatives that violate the dam safety metric will not be considered,” said Mallet. Under the new metric, the corps cannot exceed 537 days with the lake higher than 17.25 feet above sea level, and cannot exceed 20 days with a lake level above 18 feet.

“In LORS, we did not want stages to go above 17.25 feet,” she said.

The new dam safety plan allows the lake level to be above 17.25 feet up to 537 days. Even with the dike improvements, “we still have risk if we have stages above a specific level for a specific time,” she explained.

The proposed plan that eliminated releases to the St. Lucie made Lake O levels and Caloosahatchee releases worse. The plan that prioritized the Caloosahatchee River increased harmful St. Lucie releases.

The plan that limited releases to the Caloosahatchee River to beneficial flow also resulted in a violation of the dam safety limits with 59 days exceeding a lake level of 18 feet.

Plans with higher lake stages tend to do better for water supply performance, she continued. They also considered each plan’s effects on the irrigation supplies and shortages for the Seminole Tribe of Florida Big Cypress Reservation and for Brighton Reservation.

Majority of water shortages come during drought periods when lake level is low.

Mallet noted that any schedule that has higher stages in the lake increases local basin runoff into the St. Lucie.

If the lake is higher, it limits the ability of St. Lucie basin runoff to backflow into the lake, she explained. As a result, plans with reductions in damaging flows from the lake increase damaging flows from the basin runoff. 

All of the LOSOM plans target moving more water south to the stormwater treatment areas (STAs) south of Lake Okeechobee.

“We will take the deep dive into the data in our subteam meeting,” explained Lisa Aley, of the USACE Jacksonville District. She said they will look at results they like and don’t like and what factors are responsible for those results.

The goal is to have the final LOSOM document out for discussion by January 2022, with the plan to have the plan ready to implement in July 2022.

The LOSOM plan can’t control all of the factors involved, said Newton Cook of United Waterfowlers Florida. “I would like to see the lake stay between 12 and 15 feet,” he said, adding “Mother Nature is not going to let that happen.

“We all know when we get something like Irma, water is going to go east and west,” he added.

Cook urged SFWMD and the corps to take care of Lake O, the liquid heart of the Everglades system. “If you manage the lake so the lake is healthy, the Everglades will be healthy,” he said.

Nyla Pipes of One Florida Foundation noted higher lake stages in Lake Okeechobee mean more local basin runoff will go into the St. Lucie because C-44 canal won’t be able to backflow into the lake.

She said LOSOM is not the Comprehensive Everglades Restoration Plan (CERP).

“Until we open up the very bottom of the system, we cannot send more water south,” she said. “We risk blowing out the STAs if we send too much nutrient-rich Lake O water through them.”

Pipes also pointed out the water levels are just now coming down in the Water Conservation Areas (WCAs), which were flooded after Tropical Storm Eta. The WCAs need time to recover.

“If we continue to drown the tree islands, we are losing the very thing we are trying to save with the Everglades restoration project,” she added.