St Lucie-Margaret Lake
St Lucie-Margaret Lake in St. Lucie County, Florida has a water quality grade of B (Good). Water clarity: 3.8 ft visibility. Phosphorus: 22 µg/L.
- Clarity
- 3.8 ft
- Type
- Eutrophic
- Trend
- ↓ Declining
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St Lucie-Margaret Lake is a productive, nutrient-rich eutrophic lake in St. Lucie County, Florida. Water quality is graded B based on 1 sampling years through 2023. Overall water quality is declining over recent sampling years. Compared to the 4 other monitored lakes in St. Lucie County, St Lucie-Margaret Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2023-04-11. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyLow algae
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.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Murky, only visible to about 3.8 ft. Phosphorus level: 22 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.8 ft | Not graded |
| Phosphorus | 22 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near St Lucie-Margaret Lake
Compare lakeside cabins, hotels, and vacation rentals near St Lucie-Margaret Lake in St. Lucie 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.
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Fishing St Lucie-Margaret Lake
Water Quality Trend: ↓ Declining
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.9 m/yr | 3 |
| Phosphorus | ↓ Declining | +5.25 µg/L/yr | 3 |
County Ranking
Ranked #1 of 5 lakes in St. Lucie County
Nearby Lakes in St. Lucie County
Frequently asked questions about St Lucie-Margaret Lake
Where is St Lucie-Margaret Lake?
- St Lucie-Margaret Lake is a lake in St. Lucie County, Florida. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for St Lucie-Margaret Lake?
- St Lucie-Margaret Lake in St. Lucie County, Florida has a water quality grade of B (Good). Water clarity: 3.8 ft visibility. Phosphorus: 22 µg/L.
Is St Lucie-Margaret Lake safe to swim in?
- Good for swimming, clear water with low algae levels. St Lucie-Margaret Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
Explore St Lucie-Margaret Lake across LakeQuality
More Florida Lake Rankings
Other Grade B Lakes in Florida
Eutrophic Lakes in Florida
Where this data comes from
189 measurements from 3 monitoring stations, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- FLORIDA LAKEWATCH
21FLKWAT_WQX189 samples · 2020–2023
Monitoring station identifiers (3)
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.