What is the water quality grade for Willis Lake?

Willis Lake in Orange County, Florida received a water quality grade of B (Good). Water clarity: 7.2 ft visibility. Phosphorus: 6 µg/L.

Is Willis Lake safe to swim in?

Good for swimming, clear water with low algae levels. Willis Lake has an overall water quality grade of B. Always check local health department advisories before swimming.

Willis Lake

Orange County, FloridaOligotrophic

Willis Lake is a cold, clear oligotrophic lake in Orange County, Florida. Water quality is graded B based on 2 sampling years through 2025. Compared to the 531 other monitored lakes in Orange County, Willis Lake ranks #124 for water quality.

Source: EPA Water Quality Portal sampling records, Florida DNR, last sampled 2025-02-17. Grade methodology: LakeGrade methodology.

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Swimming Safety

Good for swimming, clear water with low algae levels

Water Quality Grade: B, Good

Moderate clarity, visible to about 7.2 ft. Phosphorus level: 6 µg/L. Trophic State Index: 39.

Metric	Value	Grade
Water Clarity (Secchi Depth)	7.2 ft	C
Phosphorus	6 µg/L	A
Chlorophyll-a (Algae)	No data
Trophic State Index (TSI)	39	Oligotrophic

Low nutrients, clear water, excellent for swimming

Location

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County Ranking

Ranked #124 of 532 lakes in Orange County

Cleaner Lakes Within 30 Miles

Willis Lake holds Grade B. 2 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Orange County

Big Sand Lake From Dock

More Florida Lake Rankings

Cleanest lakes in Florida

Top 25 by overall water quality score

Best swimming lakes in Florida

Grade A/B + low algae filter

Family fishing lakes in Florida

Panfish-rich, public access

All Florida lakes

Full state directory

Other Grade B Lakes in Florida

Bay-Deer Point Lake

Bay County · Clarity: 4 ft

Brevard-Clear Lake

Brevard County · Clarity: 9.8 ft

Alachua-Santa Fe Painter Canal Lake

Alachua County · Clarity: 5.5 ft

Seminole-Little Howell Lake

Seminole County · Clarity: 5 ft

Marion-Deerback Lake

Marion County · Clarity: 7 ft

Hillsborough-Flynn Lake

Hillsborough County · Clarity: 6 ft

Oligotrophic Lakes in Florida

Highlands-Sirena Lake Highlands-Verona Lake Volusia-Winnemissett Lake Bay-St. Andrew Bay Lake

Lake Size & Watershed

Watershed (drainage) area

1 sq mi

Surface area

111 acres

Mean depth (est.)

9.8 ft

Shoreline

1.6 mi

Elevation

102 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.

Regulated Pollution Sources Nearby

2 EPA-permitted facilities operate within about 5 miles of Willis Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.

Sea World
Orlando · 1.2 mi away · NPDES FL0629332
Recent violation
Discovery Cove
Orlando · 1.2 mi away · NPDES FL0622648

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)

Lake size & watershed from HydroLAKES (HydroSHEDS)

Grading methodology based on Metropolitan Council standards

Most recent sample: 2025-02-17

Monitoring stations: 1

Where to stay near Willis Lake

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