What is the water quality grade for Lake Avalon?

Lake Avalon in Collier County, Florida received a water quality grade of C (Fair). Water clarity: 1.1 ft visibility. Phosphorus: 20 µg/L.

Is Lake Avalon safe to swim in?

Generally safe for swimming, moderate water quality. Lake Avalon has an overall water quality grade of C. Always check local health department advisories before swimming.

Lake Avalon

Collier County, FloridaEutrophic

Lake Avalon is a productive, nutrient-rich eutrophic lake in Collier County, Florida. Water quality is graded C based on 2 sampling years through 2024. Compared to the 23 other monitored lakes in Collier County, Lake Avalon ranks #16 for water quality.

Source: EPA Water Quality Portal sampling records, Florida DNR, last sampled 2024-12-16. 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 1.1 ft of visibility. Phosphorus level: 20 µg/L. Trophic State Index: 61.

Metric	Value	Grade
Water Clarity (Secchi Depth)	1.1 ft	F
Phosphorus	20 µg/L	B
Chlorophyll-a (Algae)	No data
Trophic State Index (TSI)	61	Eutrophic

High nutrients, frequent algae, reduced clarity

Location

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County Ranking

Ranked #16 of 24 lakes in Collier County

Cleaner Lakes Within 30 Miles

Lake Avalon holds Grade C. 4 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Collier County

Collier-Heron Pointe Lake

Collier County

Collier-Islandwalk Lake

Collier County

Collier-Beachwalk A Lake

Collier County

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 C Lakes in Florida

Lake Lancaster West

Orange County · Clarity: 3.5 ft

Eastern Lake Outlet

Walton County · Clarity: 4.2 ft

Seminole-Secret Lake

Seminole County · Clarity: 4.5 ft

Spring Lake

Seminole County · Clarity: 2.9 ft

Polk-Fannie Lake

Polk County · Clarity: 3.5 ft

Volusia-North Talmadge Lake

Volusia County · Clarity: 4.5 ft

Eutrophic Lakes in Florida

Lake Lancaster West Flagler-Emerald Lake Eastern Lake Outlet Seminole-Secret Lake

Lake Size & Watershed

Watershed (drainage) area

6 sq mi

Surface area

47 acres

Mean depth (est.)

6.6 ft

Shoreline

1.1 mi

Elevation

13 ft

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

Regulated Pollution Sources Nearby

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

Collier County South County Wrf
Naples · 2.5 mi away · NPDES FL0141356
Recent violation

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: 2024-12-16

Monitoring stations: 1

Where to stay near Lake Avalon

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