Secret Lake
Secret Lake in Seminole County, Florida has a water quality grade of B (Good). Water clarity: 3.7 ft visibility. Phosphorus: 18 µg/L.
- Clarity
- 3.7 ft
- Typical in September
- 85°F
- Type
- Eutrophic
- Trend
- ↑ Improving
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Secret Lake is a productive, nutrient-rich eutrophic lake in Seminole County, Florida. Water quality is graded B based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. Compared to the 121 other monitored lakes in Seminole County, Secret Lake ranks #77 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-03-25. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyBacteria C
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Based on E. coli testing, Secret Lake occasionally exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 5% of 20 samples across 6 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.
Water Quality Grade: B (Good)
Murky, only visible to about 3.7 ft. Phosphorus level: 18 µg/L. Trophic State Index: 52.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.7 ft | Not graded |
| Phosphorus | 18 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 52 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Secret Lake
Compare lakeside cabins, hotels, and vacation rentals near Secret Lake in Seminole 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 Secret Lake
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 →
Water Temperature
Secret Lake typically sits around 85°F at the surface in September. Summer average is about 85°F. Usually warmest in Jun (about 85°F) and coldest in Dec (about 68°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 20 field readings (2020–2025) via the EPA Water Quality Portal. See the full Secret Lake water temperature breakdown →
Fishing Secret Lake
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.118 m/yr | 5 |
| Phosphorus | ↑ Improving | -1.8 µg/L/yr | 5 |
EPA Impairment Status
Secret Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5A).
Causes of impairment
Source: EPA ATTAINS assessment unit FL2994K · Official waterbody report · Matched by proximity (0.68 km)
County Ranking
Ranked #77 of 122 lakes in Seminole County
Nearby Lakes in Seminole County
Frequently asked questions about Secret Lake
Where is Secret Lake?
- Secret Lake is a lake in Seminole County, Florida. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Secret Lake?
- Secret Lake in Seminole County, Florida has a water quality grade of B (Good). Water clarity: 3.7 ft visibility. Phosphorus: 18 µg/L.
Is Secret Lake safe to swim in?
- Based on E. coli testing, Secret Lake occasionally exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 5% of 20 samples across 6 seasons. That works out to a bacteria swim-safety grade of C — a historical summary of past testing, not a current reading. Secret Lake has a water quality grade of B (Good). Bacteria levels can spike quickly after heavy rain, so always check Florida's current beach and health-department advisories before you swim.
What is the water temperature of Secret Lake?
- Secret Lake typically sits around 85°F at the surface in September, from 20 EPA Water Quality Portal field readings (2020–2025). That is a typical value for the month, not a live reading.
Explore Secret Lake across LakeQuality
Planning a trip around Canaveral?
Secret Lake is about 36 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 Florida Lake Rankings
Other Grade B Lakes in Florida
Eutrophic Lakes in Florida
Where this data comes from
40 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples40 samples · 2020–2025
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database