Brownor Lake
Brownor Lake in Putnam County, Florida has a water quality grade of B (Good). Water clarity: 7.4 ft visibility. Phosphorus: 9.5 µg/L.
- Clarity
- 7.4 ft
- Typical in August
- 87°F
- Type
- Mesotrophic
- Trend
- ↓ Declining
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Brownor Lake is a mesotrophic lake in Putnam County, Florida. Water quality is graded B based on 1 sampling years through 2022. Overall water quality is declining over recent sampling years. Compared to the 27 other monitored lakes in Putnam County, Brownor Lake ranks #17 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2022-08-15. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyBacteria A
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, Brownor Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 14 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.
Water Quality Grade: B (Good)
Moderate clarity, visible to about 7.4 ft. Phosphorus level: 9.5 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.4 ft | Not graded |
| Phosphorus | 9.5 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Brownor Lake
Compare lakeside cabins, hotels, and vacation rentals near Brownor Lake in Putnam 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 Brownor Lake
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Planning a whole trip? See where to stay at Florida’s top lakes →
Water Temperature
Brownor Lake typically sits around 87°F at the surface in August. Summer average is about 85°F. Usually warmest in Aug (about 87°F) and coldest in Jan (about 61°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 30 field readings (2021–2022) via the EPA Water Quality Portal. See the full Brownor Lake water temperature breakdown →
Fishing Brownor Lake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -1.354 m/yr | 5 |
| Phosphorus | ↓ Declining | +0.65 µg/L/yr | 5 |
EPA Impairment Status
Brownor Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit FL2617A · Official waterbody report · Matched by proximity (0.62 km)
County Ranking
Ranked #17 of 28 lakes in Putnam County
Nearby Lakes in Putnam County
Frequently asked questions about Brownor Lake
Where is Brownor Lake?
- Brownor Lake is a lake in Putnam County, Florida. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Brownor Lake?
- Brownor Lake in Putnam County, Florida has a water quality grade of B (Good). Water clarity: 7.4 ft visibility. Phosphorus: 9.5 µg/L.
Is Brownor Lake safe to swim in?
- Based on E. coli testing, Brownor Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 14 samples across 2 seasons. That works out to a bacteria swim-safety grade of A — a historical summary of past testing, not a current reading. Brownor 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 Brownor Lake?
- Brownor Lake typically sits around 87°F at the surface in August, from 30 EPA Water Quality Portal field readings (2021–2022). That is a typical value for the month, not a live reading.
Explore Brownor Lake across LakeQuality
Planning a trip around Fort Matanzas?
Brownor Lake is about 26 miles from Fort Matanzas National Monument. 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 Fort Matanzas →More Florida Lake Rankings
Other Grade B Lakes in Florida
Mesotrophic Lakes in Florida
Where this data comes from
28 measurements from 1 monitoring station, 2021–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- FL Dept. of Environmental Protection, Northeast District
21FLA_WQX28 samples · 2021–2022
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