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D

Lake Seminole

Pinellas County, FloridaHypereutrophic

Lake Seminole is a highly nutrient-loaded hypereutrophic lake in Pinellas County, Florida. Water quality is graded D based on 2 sampling years through 2025. Compared to the 54 other monitored lakes in Pinellas County, Lake Seminole ranks #30 for water quality.

Source: EPA Water Quality Portal sampling records, Florida DNR, last sampled 2025-02-13. Grade methodology: LakeGrade methodology.

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Swimming Safety

Swimming not recommended, poor water quality with high algae risk

Water Quality Grade: D, Poor

Very murky, less than 1 ft of visibility. Phosphorus level: 63 µg/L. Trophic State Index: 71.

MetricValueGrade
Water Clarity (Secchi Depth)1 ftF
Phosphorus63 µg/LD
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)71Hypereutrophic

Very high nutrients, dense algae, poor clarity

Location

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County Ranking

Ranked #30 of 55 lakes in Pinellas County

Nearby Lakes in Pinellas County

D
Pinellas-Seminole Lake
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D
Lake Seminole
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D
Lake Seminole
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B
Mckay Creek Lake
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F
Pinellas-Jungle North Inlet Lake
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Pinellas-Jungle Outlet Lake
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More Florida Lake Rankings

Cleanest lakes in Florida

Top 25 by overall water quality score

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Grade A/B + low algae filter

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Panfish-rich, public access

All Florida lakes

Full state directory

Other Grade D Lakes in Florida

Flagler-Emerald Lake

Flagler County · Clarity: 1.8 ft

Ftt Lake

Indian River County · Clarity: 2.3 ft

Lake Orlando East

Orange County · Clarity: 2 ft

Lake Rowena

Orange County · Clarity: 3 ft

Lake G

Orange County · Clarity: 2 ft

Putnam-Suggs Lake

Putnam County · Clarity: 2 ft

Hypereutrophic Lakes in Florida

Polk-Little Bass LakeAlicetst LakePolk-Big Bass LakeLake Roberta

Regulated Pollution Sources Nearby

5 EPA-permitted facilities operate within about 5 miles of Lake Seminole under Clean Water Act (NPDES) discharge permits, including 5 classified by the EPA as major dischargers.

  • Seminole, City Of
    Seminole · 1.4 mi away · NPDES FLS648388
    Major
  • Redington Beach, Town Of
    Redington Beach · 2.6 mi away · NPDES FLS648477
    Major
  • Madeira Beach, City Of
    Madeira Beach · 3.3 mi away · NPDES FLS648272
    Major
  • North Redington Beach, Town Of
    North Redington Beach · 3.3 mi away · NPDES FLS648469
    Major
  • Redington Shores, Town Of
    Redington Shores · 3.4 mi away · NPDES FLS648485
    Major

Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.

Data Sources

Water quality data from the EPA Water Quality Portal

Regulated discharger data from EPA ECHO (ICIS-NPDES)

Grading methodology based on Metropolitan Council standards

Most recent sample: 2025-02-13

Monitoring stations: 1

Where to stay near Lake Seminole

Compare lakeside cabins, hotels, and vacation rentals near Lake Seminole in Pinellas County, Florida — live availability and prices for your trip.

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