Withlacoochee / Tsala Apopka Update - 9/16/2026

Vegetation Causing High Water at Dunnellon; Tsala Apopka Structures Open

 

Important: We do not have the Tsala Apoka structures open because of flooding along the Withlacoochee. Besides Dunnellon, the remainder of the Withlacoochee River is below normal for this time of year.

 

Rainfall and Water Levels

• Our region is still being impacted by below average rainfall over the past 18 months.
• The Withlacoochee River remains below normal for this time of year and the Tsala Apopka Chain of Lakes are still 4 to 5 feet below their high levels.
• Last week, the Green Swamp got some decent rain and we’re finally seeing the Withlacoochee River rise near Trilby, Ridge Manor, Croom, Nobleton and Hwy 48.

 

Flood Warning at Dunnellon

• You may have seen a flood alert for the Withlacoochee River at Dunnellon (US 41).
• River levels don’t fluctuate much at that location because of the Inglis Dam and Lake Rousseau.
• But over the past several weeks, the water has been steadily rising and has now reached minor flood stage, 18 inches higher than its normal level.
• This high water has nothing to due with rainfall or river conditions anywhere else along the Withlacoochee. Remember the rest of the Withlacoochee is very low.
• Field inspections on Monday evening identified excessive hydrilla growth between US 41 and Lake Rousseau that is causing a damming effect, leading to elevated water levels at Dunnellon.
• We are coordinating with the proper agencies to identify a solution and take action.

 

Tsala Apopka Chain of Lakes

• Totally separate from the high-water situation in Dunnellon, river levels from the Green Swamp to Hwy 48 have begun to rise from rainfall over the past week.
• This has allowed us to finally open structures to begin moving water into the Tsala Apopka Chain of Lakes.
• Here is a breakdown of which structures are open or closed:
  • Leslie Heifner and Floral City structures are both fully open, bringing all available river water into the Floral City Pool.
  • Golf Course structure is also fully open, however, the flow into the Inverness Pool is negligible because of how low the Floral City Pool is. Basically, there’s hardly any water in the canal between them.
  • Moccasin Slough structure remains closed because the wetlands upstream are still dry, no water is available to flow.
  • Brogden Bridge structure remains closed because we’re unable to move any measurable flow into the Inverness Pool, so nothing can be let into Hernando yet.
  • Once the Floral City Pool rises, and flow is moving into the Inverness lakes, we’ll be able to share that flow with the Hernando Pool.
  • S-353 and Van Ness structures, which are only used to move water out of the lake chain, have been closed since the fall of 2024 and remain closed.
• Last week’s rain should allow us to keep the structures open for a while, and more rainfall will prolong the flow into the lakes.
• The current inflow is minor, however, and will not cause a quick rise in the lakes, but if the river keeps rising and the lakes also receive above average rainfall, we could see the lakes come up some.

 

Best regards,

 Mark

 

Withlacoochee River near Dunnellon (9/14/2026)

 

 

Low Water in Canal Between Tsala Apopka Pools (9/15/2026)

 

 

Mark Fulkerson, Ph.D., P.E.

Chief Professional Engineer

Southwest Florida Water Management District

 (352) 269-6073 (office)

(352) 279-4493 (cell)

Mark.Fulkerson@WaterMatters.org

 Withlacoochee River Watershed Initiative