Yankee Lake
Seminole County, FloridaMesotrophic
Yankee Lake is a mesotrophic lake in Seminole County, Florida. Water quality is graded C based on 2 sampling years through 2025. Compared to the 167 other monitored lakes in Seminole County, Yankee Lake ranks #69 for water quality.
Source: EPA Water Quality Portal sampling records, Florida DNR, last sampled 2025-04-10. Grade methodology: LakeGrade methodology.
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Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Very murky, less than 3 ft of visibility. Phosphorus level: 7.5 µg/L. Trophic State Index: 47.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3 ft | F |
| Phosphorus | 7.5 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 47 | Mesotrophic |
Moderate nutrients, good water quality
Location
County Ranking
Ranked #69 of 168 lakes in Seminole County
Cleaner Lakes Within 30 Miles
Yankee Lake holds Grade C. 5 nearby lakes hold higher grades.
- BLake MarkhamSeminole County · 1.1 mi · Higher grade (C → B)
- BSylvan LakeSeminole County · 1.2 mi · Higher grade (C → B)
- BSeminole-West Crystal LakeSeminole County · 5.4 mi · Higher grade (C → B)
- BSeminole-Sylvan LakeSeminole County · 1.1 mi · Higher grade (C → B)
- BSeminole-Como LakeSeminole County · 4.7 mi · Higher grade (C → B)
Nearby Lakes in Seminole County
More Florida Lake Rankings
Other Grade C Lakes in Florida
Orange County · Clarity: 3.5 ft
Walton County · Clarity: 4.2 ft
Polk County · Clarity: 3.5 ft
Volusia County · Clarity: 4.5 ft
Walton County · Clarity: 3 ft
Alachua County · Clarity: 3 ft
Mesotrophic Lakes in Florida
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Yankee Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger.
- Sces/Northwest Regional StpSanford · 0.6 mi away · NPDES FL0042625Major
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: 2025-04-10
Monitoring stations: 1
Where to stay near Yankee Lake
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