What is a TMDL?

A Total Maximum Daily Load (TMDL) is the amount of a specific pollutant allowed to be discharged into a water body while still allowing the water body to meet state water quality standards.

Collier County has four WBIDs that have TMDLs. Lake Trafford, Cocohatchee River, and Gordon River Extension were set in 2008. Townsend Canal TMDL was developed in 2019.

The Gordon River WBID has a TMDL for dissolved oxygen for which Florida Department of Environmental Protection (FDEP) has listed nutrients as the cause of the impairment. A total nitrogen (0.74 mg/l) limit has been established by the adopted TMDL based on concentrations in the water column.  

The Cocohatchee River WBID has a TMDL for fecal coliform. The TMDL requires a 65% reduction of fecal coliform from nonpoint sources. 

The Lake Trafford has TMDLs for three parameters—nutrients, unionized ammonia and dissolved oxygen. The TMDL requires a nutrient reduction of 60% total nitrogen and 77% total phosphorus. The assumption is made that if these load reductions are met, that dissolved oxygen and unionized ammonia will respond positively.  

Townsend Canal has a TMDLs for total nitrogen, total phosphorus and biochemical oxygen demand. These TMDLs require a 37% reduction in total nitrogen, a 38% reduction in total phosphorus, and a 37% reduction in biochemical oxygen demand.

Find out more about the Total Maximum Daily Loads process.

Once a TMDL is adopted, the next step would be to develop a Basin Management Action Plan (BMAP). 

Updated 2/20/2024