Pinellas-Harbor-Isle Lake
Pinellas County, FloridaView mapDirections
Florida DEP publishes the water-quality measurements for Pinellas-Harbor-Isle Lake. Here is what has been measured.
- Eutrophic
- Public access
- Limited data
Pinellas-Harbor-Isle Lake in Pinellas County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 3.5 ft visibility. Phosphorus: 115.5 µg/L.
Pinellas-Harbor-Isle Lake is a productive, nutrient-rich eutrophic lake in Pinellas County, Florida. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 33 other monitored lakes in Pinellas County, Pinellas-Harbor-Isle Lake ranks #22 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2021-07-30. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Pinellas-Harbor-Isle Lake is safe to swim in today is a call for the Florida Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Pinellas-Harbor-Isle Lake
These are the measurements Florida DEP publishes for Pinellas-Harbor-Isle Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 3.5 ft. Phosphorus 115.5 µg/L. TSI 66.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 116µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 66 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Pinellas-Harbor-Isle Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Pinellas-Harbor-Isle Lake typically sits around 78°F at the surface in October. Summer average is about 89°F. Usually warmest in Jul (about 90°F) and coldest in Feb (about 65°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (65°F) to its warmest (90°F).
Typical surface water temperature by month, from 29 field readings (2020–2022) via the EPA Water Quality Portal. See the full Pinellas-Harbor-Isle Lake water temperature breakdown →
Stays via Stay22
Stays near Pinellas-Harbor-Isle Lake
Compare lakeside cabins, hotels, and vacation rentals near Pinellas-Harbor-Isle Lake in Pinellas 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Pinellas-Harbor-Isle Lake are listed below.
Top-rated places to stay near Pinellas-Harbor-Isle Lake
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Fishing Pinellas-Harbor-Isle Lake
Water quality readings over time
3 seasons of samples on record (2020–2022). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Phosphorus
Improving-8.5 µg/L/yr3 years
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Pinellas-Harbor-Isle Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Duke Energy Florida - Bartow PlantSt Petersburg · 1.7 mi away · NPDES FL0000132MajorRecent 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.
Nearby Lakes in Pinellas County
Frequently asked questions about Pinellas-Harbor-Isle Lake
Where is Pinellas-Harbor-Isle Lake?
- Pinellas-Harbor-Isle Lake is a lake in Pinellas County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Pinellas-Harbor-Isle Lake?
- Pinellas-Harbor-Isle Lake in Pinellas County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 3.5 ft visibility. Phosphorus: 115.5 µg/L.
Is Pinellas-Harbor-Isle Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Pinellas-Harbor-Isle Lake?
- Pinellas-Harbor-Isle Lake typically sits around 78°F at the surface in October, from 29 EPA Water Quality Portal field readings (2020–2022). That is a typical value for the month, not a live reading.
Can I fish at Pinellas-Harbor-Isle Lake?
- Public access to Pinellas-Harbor-Isle Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Florida's fish and wildlife agency, so check its current regulations before you go.
Explore Pinellas-Harbor-Isle Lake across LakeQuality
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Where this data comes from
42 measurements from 3 monitoring stations, 2020–2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- FLORIDA LAKEWATCH
21FLKWAT_WQX42 samples · 2020–2021
Monitoring station identifiers (3)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)