Collier-Islandwalk Lake
Collier-Islandwalk Lake in Collier County, Florida has a water quality grade of C (Fair). Water clarity: 3.3 ft visibility. Phosphorus: 44.5 µg/L.
- Clarity
- 3.3 ft
- Type
- Eutrophic
- Trend
- ↑ Improving
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Collier-Islandwalk Lake is a productive, nutrient-rich eutrophic lake in Collier County, Florida. Water quality is graded C based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. Compared to the 16 other monitored lakes in Collier County, Collier-Islandwalk Lake ranks #13 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-03-07. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Very murky, less than 3.3 ft of visibility. Phosphorus level: 44.5 µg/L. Trophic State Index: 59.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.3 ft | Not graded |
| Phosphorus | 44.5 µg/L | Fair |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 59 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Collier-Islandwalk Lake
Compare lakeside cabins, hotels, and vacation rentals near Collier-Islandwalk Lake in Collier 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 Collier-Islandwalk Lake
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Fishing Collier-Islandwalk Lake
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.035 m/yr | 4 |
| Phosphorus | ↑ Improving | -8 µg/L/yr | 4 |
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Collier-Islandwalk Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger.
- San Carlos Estates Water Control DistrictFort Myers · 3.3 mi away · NPDES FLS266981Major
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.
County Ranking
Ranked #13 of 17 lakes in Collier County
Nearby Lakes With Higher Grades
Collier-Islandwalk Lake holds Grade C. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Collier County
Frequently asked questions about Collier-Islandwalk Lake
Where is Collier-Islandwalk Lake?
- Collier-Islandwalk Lake is a lake in Collier County, Florida. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Collier-Islandwalk Lake?
- Collier-Islandwalk Lake in Collier County, Florida has a water quality grade of C (Fair). Water clarity: 3.3 ft visibility. Phosphorus: 44.5 µg/L.
Is Collier-Islandwalk Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Collier-Islandwalk Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.
Explore Collier-Islandwalk Lake across LakeQuality
More Florida Lake Rankings
Other Grade C Lakes in Florida
Eutrophic Lakes in Florida
Where this data comes from
386 measurements from 8 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- FLORIDA LAKEWATCH
21FLKWAT_WQX386 samples · 2020–2025
Monitoring station identifiers (8)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)