Florida has more than 50,000 miles of rivers and streams, 7,800 lakes, 4,000 square miles of estuaries, and more than 1,000 recognized springs. The 2024 Integrated Water Quality Assessment for Florida identified impairment across many kinds of stream and lake segments, including measures of oxygen, nutrients, bacteria, metals, and habitat. The figures below keep the geography and measurement context attached to each statistic.
Contents
- Florida’s water-quality footprint
- How Florida assesses its waters
- Impaired Florida streams by pollutant or condition
- Impaired Florida lakes by pollutant or condition
- Springs, coastlines, and aquatic preserves
- Wastewater and long-term monitoring
Florida’s water-quality footprint
Florida DEP Water Quality Standards describes a state with an unusually broad range of aquatic resources. The statewide inventory includes:
- Over 50,000 miles of rivers and streams.
- 7,800 lakes.
- 4,000 square miles of estuaries.
- More than 1,000 recognized springs.
These figures describe the scale of the waters being managed; they are not measurements of water condition. A river mile, lake segment, estuary area, or spring count can be part of an assessment system without being classified as impaired.
The 2024 Integrated Water Quality Assessment for Florida reports impairment in separate stream and lake tables. Those tables use segments rather than treating every waterbody as one uniform measurement. For streams, the listed results span 4,808 miles for the largest stream-mile entry. For lakes, the table covers 853 segments and 2,209,913 acres across all listed lake impairments.
The units matter when comparing results. Stream findings are reported in miles and segment counts, while lake findings are reported in acres and segment counts. A large acreage figure does not necessarily represent more individual lake segments, and a high segment count does not necessarily represent the greatest area.
How Florida assesses its waters
Florida DEP Assessment Lists says Florida uses 29 major watersheds, or basins, for assessment purposes. Those basins are organized into 5 basin groups. Historically, Florida’s watershed management approach rotated through the 29 basins on a 5-year cycle.
The current biennial assessment process evaluates all basins every 2 years rather than every 5 years. Florida DEP Hot Topic: State Water Quality also states that Florida assesses about 20% of its watersheds each year to identify impaired waters. These descriptions reflect related parts of the assessment system, so the time period and wording should be retained when using them: one source describes the biennial process, while the other gives an approximate annual share.
The assessment framework is designed to identify impaired waters, not to produce one single statewide “water quality score.” The 2024 assessment therefore presents separate entries for conditions such as dissolved oxygen, nutrients, bacteria, metals, turbidity, and biological indicators. Each entry pairs a number of impaired segments with the stream miles or lake acres covered by that entry.
Impaired Florida streams by pollutant or condition
The stream results in the 2024 Integrated Water Quality Assessment for Florida show dissolved oxygen as the largest listed stream-mile category. Dissolved oxygen, measured as percent saturation, impaired 469 stream segments covering 4,808 miles. That is also the largest stream-mile figure listed in the table.
Other prominent stream entries were:
- E. coli: 255 stream segments and 1,914 miles.
- Total phosphorus nutrients: 189 segments and 1,862 miles.
- Total nitrogen nutrients: 139 segments and 1,762 miles.
- Fecal coliform: 169 segments and 1,762 miles.
- Macrophytes nutrients: 113 segments and 1,228 miles.
- Iron: 97 segments and 1,201 miles.
- Chlorophyll a nutrients: 107 segments and 1,063 miles.
- Biology (SCI): 97 segments and 853 miles.
The bacteria and nutrient entries show why a segment count should be read alongside its mileage. E. coli appears in 255 stream segments, while total phosphorus appears in 189, but their listed coverage is 1,914 and 1,862 miles respectively. Fecal coliform has fewer segments than either of those entries, at 169, while covering 1,762 miles.
| Stream condition in the 2024 assessment | Impaired segments | Coverage |
|---|---|---|
| Dissolved oxygen, percent saturation | 469 | 4,808 miles |
| E. coli | 255 | 1,914 miles |
| Total phosphorus nutrients | 189 | 1,862 miles |
| Total nitrogen nutrients | 139 | 1,762 miles |
| Iron | 97 | 1,201 miles |
| Chlorophyll a nutrients | 107 | 1,063 miles |
The remaining listed stream categories were smaller in the table but still quantify distinct water-quality concerns. Algal mats nutrients impaired 28 segments covering 392 miles. Lead impaired 31 segments covering 380 miles. Nitrate-nitrite nutrients impaired 16 segments covering 245 miles. Turbidity impaired 3 segments covering 89 miles, while specific conductance impaired 7 segments covering 78 miles.
Additional entries included dissolved oxygen with 5 segments covering 68 miles, silver with 3 segments covering 59 miles, and chloride with 3 segments covering 41 miles. Monthly geometric-mean E. coli impaired 1 stream segment covering 31 miles. This monthly geometric-mean entry is distinct from the broader E. coli entry and should not be combined with it.
Impaired Florida lakes by pollutant or condition
The lake results in the 2024 Integrated Water Quality Assessment for Florida use acres as the coverage measure. Nutrients measured as total phosphorus impaired 211 lake segments covering 731,882 acres. This was the largest acreage entry in the lake table. Nutrients measured as total nitrogen impaired 173 segments covering 337,308 acres.
Several other lake categories also covered hundreds of thousands of acres:
- Turbidity: 8 lake segments and 334,209 acres.
- Iron: 7 segments and 295,298 acres.
- Chlorophyll a nutrients: 193 segments and 291,727 acres.
- Biology (LVI): 151 segments and 134,792 acres.
- Dissolved oxygen, percent saturation: 72 segments and 40,846 acres.
The combination of segment count and acreage produces useful contrasts. Turbidity covered 334,209 acres across 8 lake segments, while chlorophyll a nutrients covered 291,727 acres across 193 segments. Total phosphorus had both a high segment count, at 211, and the largest listed acreage, at 731,882 acres. These figures should be read as the coverage reported for each assessment category, not as additive totals across categories, because the same waterbody or area can appear in more than one category.
The rest of the lake entries were more limited by either segments or acreage. Pesticides in fish tissue impaired 4 lake segments covering 32,361 acres. Lead impaired 15 segments covering 7,707 acres. Fecal coliform impaired 8 segments covering 1,416 acres. Escherichia coli impaired 4 segments covering 156 acres.
The table also listed pH at 1 lake segment and 682 acres; nutrients described as other information at 1 segment and 485 acres; specific conductance at 1 segment and 363 acres; nutrients associated with algal mats at 1 segment and 274 acres; and nutrients associated with nitrate-nitrite at 1 segment and 274 acres. Copper impaired 1 lake segment covering 122 acres, and silver impaired 1 segment covering 11 acres.
Across all listed lake impairment entries, the assessment table covered 853 segments and 2,209,913 acres. That total is a table-wide coverage figure, not a claim that every listed category represents separate, non-overlapping acreage.
Springs, coastlines, and aquatic preserves
Springs are a major part of Florida’s water-quality landscape. Florida DEP Springs recognizes more than 1,000 springs, while Florida DEP Protect and Restore Springs lists 24 springs as impaired. The two figures have different meanings: one is a count of recognized springs, and the other is a count identified as impaired by that source.
Florida’s coastal and estuarine resources are also measured at a large geographic scale. Florida DEP Water Topics reports 43 aquatic preserves encompassing 2.9 million acres. The same source reports 825 miles of sandy coastline under Florida management.
The preserve acreage and coastline mileage are management figures, not impairment totals. They help define the extent of protected or managed waters and shoreline where water-quality programs operate. Similarly, the statewide total of 4,000 square miles of estuaries describes the resource base rather than a quantified condition rating.
Wastewater and long-term monitoring
Florida DEP Wastewater in Florida reports over 4,100 individually permitted domestic wastewater and industrial wastewater facilities. This is a facility count, not a discharge volume or an impairment count. It indicates the scale of the permitted wastewater-management system across the state.
Florida DEP Coral Reef Water Quality Data Compilation Year 4 states that the coral reef water-quality database was updated through 2023 for 8 programs meeting the inclusion criteria. The “through 2023” date is important: it identifies the latest period covered by that database update rather than a current-year measurement.
The Florida DEP Water Quality Monitoring at ANERR source reports a longer-running monitoring program. The ANERR water-quality program has monitored four locations in the bay continuously since 1992. It also collects monthly nutrient and chlorophyll-a samples at 11 bay sites.
Those ANERR figures describe monitoring design and duration. Four locations monitored continuously since 1992 are not the same thing as 11 sites receiving monthly samples, and neither number should be treated as a statewide monitoring total. The program provides a specific bay-level example of how repeated measurements can be collected over time, while the 2024 Integrated Water Quality Assessment provides the statewide assessment categories and coverage figures.