Water Quality Impairments of Nine Southwest Florida Counties
Our Southwest Florida Water Quality Report
Understanding factors contributing to water quality impairment in Florida is important for determining sources and eventual planning for restoration.
The purpose of this assessment is to summarize water quality impairment in nine Southwest Florida counties between 2018 and 2020 using consistent assessment criteria gathered from FDEP’s (Florida Department of Environmental Protection) annual comprehensive verified list of impaired waters.
The counties included are Collier, Lee, Charlotte, Sarasota, Manatee, Hillsborough, Pinellas, Hendry and Glades.
Assessing water quality impairment on a geo-political basis, such as a county, is relevant in that most state-mandated restoration programs, such as Basin Management Action Plans, are implemented primarily by local government stakeholders.
About the Report
County Demographics and Land Area
- Among the nine counties assessed, population is largely independent of county land area
- Factors include local, state and federal land purchases for conservation along with high population density coastal communities
- Lee, Manatee, Collier and Hillsborough counties ranked as the highest rate of population increase respectively since 2018
- Population increase drastically raises the probability for increased water quality impairment
- Rapidly increasing impervious areas resulting from high growth rates and development accelerate stormwater runoff – a known contributor to water quality degradation
Water Quality Impairment Contributors
- Unique impairments help to establish a baseline for tracking cumulative change
- A waterbody can have multiple parameters verified as impaired by the FDEP
- Tracking the percent of total waterbodies impaired within a county can be an important component for understanding overall water quality status
- Comparing annual net change in total impairments ranks Lee County first at a 36% increase between 2018 and 2020
- Top factors that contribute pollutants to receiving waters include urban development and impervious area associated with development
Annual Change in Water Quality Parameters
- The four major impairments of waters within the nine-county region include fecal bacteria, nutrients, metals and dissolved oxygen (DO)
- Nitrogen and phosphorus are the primary nutrients that define impairment
- Fecal bacteria parameters include fecal coliform, E. coli and enterococci
- Representative metals that define impairment include iron, copper and lead
County Rank for Impairment Status
- Six metrics that define or contribute to water quality impairment were used to determine trends with respect to change in impairment status
- Each county was ranked for each of the six metrics and an average rank was calculated for determining the overall rank
- High-ranking counties (Manatee, Lee & Hillsborough respectively) indicate the greatest recent trend towards impairments and worsening water quality