Trtl Lake
Lake County, FloridaView mapDirections
Florida DEP publishes the water-quality measurements for Trtl Lake. Here is what has been measured.
- Eutrophic
- Impaired · Algal growth
Trtl Lake in Lake County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 1.8 ft visibility. Phosphorus: 81.2 µg/L.
Trtl Lake is a productive, nutrient-rich eutrophic lake in Lake County, Florida. Compared to the 127 other monitored lakes in Lake County, Trtl Lake ranks #121 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-04-16. Methodology: how these readings are compared.
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Trtl Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, impaired biota (cause unknown), nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Trtl Lake 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 Trtl Lake
These are the measurements Florida DEP publishes for Trtl Lake, 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 1.8 ft of visibility. Phosphorus 81.2 µg/L. TSI 68.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 81.2µg/L | Poor GoodFairPoor |
| 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. | 68 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Trtl Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Trtl Lake typically sits around 78°F at the surface in October. Summer average is about 87°F. Usually warmest in Aug (about 88°F) and coldest in Dec (about 61°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (61°F) to its warmest (88°F).
Typical surface water temperature by month, from 128 field readings (2010–2025) via the EPA Water Quality Portal. See the full Trtl Lake water temperature breakdown →
Stays via Stay22
Stays near Trtl Lake
Compare lakeside cabins, hotels, and vacation rentals near Trtl Lake in Lake 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Trtl Lake are listed below.
Top-rated places to stay near Trtl Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Florida’s top lakes →
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Fishing Trtl Lake
Water Quality Trend: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Stable+0.29 µg/L/yr6 years
EPA Impairment Status
Trtl Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit FL2819A · Official waterbody report
Nearby Lakes in Lake County
Frequently asked questions about Trtl Lake
Where is Trtl Lake?
- Trtl Lake is a lake in Lake County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Trtl Lake?
- Trtl Lake in Lake County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 1.8 ft visibility. Phosphorus: 81.2 µg/L.
Is Trtl Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Trtl Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, impaired biota (cause unknown), nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Trtl Lake?
- Trtl Lake typically sits around 78°F at the surface in October, from 128 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
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Where this data comes from
96 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- St. Johns River Water Management District
21FLSJWM_WQX96 samples · 2020–2025
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.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database