STUART -- At their meeting tonight, the Stuart City Commission will discuss a plan to file a lawsuit against the U.S. Army Corps of Engineers.

The agenda for the Jan. 27 meeting includes the following resolution:

“Whereas the City Commission believes that it is in the best interest of the residents of Stuart that it file a legal challenge against the Army Corps of Engineers to address the Lake Okeechobee Discharge schedule; and,

“Whereas, Commissioner Matheson has explained to commission that the current operational schedule for Lake Okeechobee will result in toxic discharges during the summer months and the only way to prevent irreparable harm is to file suit against the Army Corps of Engineers to prevent same from occurring.

“Whereas the City Commission believes it is in the best interests of the residents of Stuart to seek legal intervention and encourage the Army Corps of Engineers to use its additional operational flexibility to take the necessary steps to lower the current lake levels to the lake is below 11 feet above sea level on June 1, 2020 in order to prevent the toxic algae discharges during the summer months …

“The City Commission of the City of Stuart, Florida directs the City Attorney to pursue a lawsuit against the Army Corps of Engineers and relative defendants to seek to redress for the Lake Schedule and obtain relief from the toxic discharges.”

The meeting, which starts at 5:30 p.m. will be at the Stuart City Hall, 121 S.W. Flagler Ave. in Stuart.

On Monday, Lake Okeechobee was at 12.81 feet, down 0.12 feet from the previous week, and well below the average of 14.69 feet for this date, based on historical data from 1965-2007. With about 13 weeks to go before the start of the wet season, the slow lake level decline during the 2019-2020 dry season should bring the lake under 12 feet before the wet season starts.

On Friday, Jan. 24, the U.S. Army Corps of Engineers stated they plan to maintain the current dry season plan for Lake Okeechobee.

The Corps will continue to release water from the lake to the Caloosahatchee in a pulse pattern that averages 650 cubic feet per second (cfs) over a seven-day period measured at the W.P. Franklin Lock and Dam (S-79).

No releases are planned through the St. Lucie Lock and Dam (S-80).

For the past week, the flow at the Moore Haven Lock into the Caloosahatchee River has averaged 809 cubic feet per second. Flow into the St. Lucie Canal at Port Mayaca has averaged 376 cfs. When there is little or no local basin rainfall, some flow from the lake to the St. Lucie Canal is needed to maintain the water level in the canal required for boat traffic, offsetting water lost to evaporation into the air and percolation into the earth. No water from the lake has been released through the St. Lucie Lock.

For the past seven days, flow south from the lake has averaged 1,597 cfs for water supply to the agricultural areas, water conservation areas, urban and natural areas south of the lake.

According to the corps, when local basin runoff meets or exceeds the 650 cfs targeted release at W.P. Franklin Lock and Dam, no water will be released from Lake Okeechobee at Moore Haven Lock and Dam (S-77). However, when there is little or no rainfall in the basin, it may require that more than 650 cfs be released at Moore Haven in order to ensure the 650 cfs flow at the Franklin Lock, because some of the flow from the lake is lost along the way.

The low of 12 feet and high of 15 feet is optimal for the health of the lake according to the draft RECOVER Lake Okeechobee Stage Envelope Performance Measure, published online on Dec. 5, 2019.

“A wide body of published research documents the benefits of seasonally variable water levels within the range of 12.0 feet as a June-July low and 15.0 feet as a November-January high, on the plant and animal communities of Lake Okeechobee,” the documentation states.

Keeping the lake in the healthy 12-to-15 feet range has many benefits, the report continues:

• Falling water levels from late winter to spring concentrates prey resources in the littoral zone for improved wading bird foraging and nesting.

• Water levels near 12 feet benefit submerged plants and bulrush at the outer edges of the marsh by reducing light attenuation in the summer months and promoting growth of underground biomass for survival during turbid, high-water events.

• A natural rocky reef in the southern portion of the lake isolates turbid water from large areas of the near-shore zone at a lake stage around 14 feet. This helps improve water clarity, promotes submerged aquatic vegetation (SAV) and reduces phosphorus levels.

• Seasonal variation within the 12-to-15 feet envelope results in annual flooding and drying of the majority of the marsh, which favors development of a diverse emergent plant community and reduces muck accumulation.

• Extreme high stages allows wind-driven waves to uproot SAV.

• High stages allow deposition of mud into the near-shore regions, covering sand and peat sediments and reducing their suitability for SAV.

Levels above the target range are harmful to the lake, the report continues.

• High stages transport nutrient-rich water from the mid-lake region into the littoral zone where the higher nutrient levels encourage the growth of invasive aquatic vegetation which crowds out the native SAV.

While rare, occasional low lake stages can benefit the lake’s marshes, extreme low lake levels — more often than once a decade — can also be harmful, the report continues.

• Low lake stages result in direct losses of habitat and can severely limit or even eliminate entire breeding seasons for many species of fish and wildlife.

• Exposing peak in the southern portions of the lake can degrade habitat for the endangered Okeechobee gourd and increase risk of peak fires, leading to a permanent loss of marsh elevation.

• Ecological recovery from extreme low lake stages can take multiple years.

Ideally, the lake should slowly rise during the wet season and slowly fall during the dry season.