Lake Theresa
Orange County, FloridaView mapDirections
Florida DEP publishes the water-quality measurements for Lake Theresa. Here is what has been measured.
- Limited data
Lake Theresa in Orange County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 2.4 ft visibility.
Lake Theresa is a lake in Orange County, Florida. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2022-10-17. Methodology: how these readings are compared.
Swimming conditions
No readingBacteria tested: exceedances
Based on E. coli testing, Lake Theresa routinely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 28.6% of 7 samples across 2 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Florida’s current beach and health-department advisories before swimming.
Whether Lake Theresa is safe to swim in today is a call for the Florida Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lake Theresa
These are the measurements Florida DEP publishes for Lake Theresa, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2.4 ft of visibility. TSI 65.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 65 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Lake Theresa
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Lake Theresa typically sits around 81°F at the surface in October. Summer average is about 86°F. Usually warmest in Jun (about 87°F) and coldest in Feb (about 66°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (66°F) to its warmest (87°F).
Typical surface water temperature by month, from 92 field readings (2010–2022) via the EPA Water Quality Portal. See the full Lake Theresa water temperature breakdown →
Stays via Stay22
Stays near Lake Theresa
Compare lakeside cabins, hotels, and vacation rentals near Lake Theresa in Orange County, Florida — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Lake Theresa
Prices for Oct 16–18, 4 adults. Change dates on the map below.
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Planning a whole trip? See where to stay at Florida’s top lakes →
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Fishing Lake Theresa
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Phosphorus
Worsening+1.76 µg/L/yr6 years
Nearby Lakes in Orange County
Frequently asked questions about Lake Theresa
Where is Lake Theresa?
- Lake Theresa is a lake in Orange County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Lake Theresa?
- Lake Theresa in Orange County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 2.4 ft visibility.
Is Lake Theresa safe to swim in?
- Based on E. coli testing, Lake Theresa routinely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 28.6% of 7 samples across 2 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Lake Theresa is safe to swim in today is a call for Florida's water agency and the county health department; check their current beach advisories before you swim.
What is the water temperature of Lake Theresa?
- Lake Theresa typically sits around 81°F at the surface in October, from 92 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.
Explore Lake Theresa across LakeQuality
Planning a trip around Canaveral?
Lake Theresa is about 39 miles from Canaveral National Seashore. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Canaveral →More lakes in Florida
Other Lakes in Florida
Eutrophic Lakes in Florida
Where this data comes from
8 measurements from 1 monitoring station, 2021–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples8 samples · 2021–2022
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.