Hillsborough-Calm Lake
Hillsborough-Calm Lake in Hillsborough County, Florida is not rated for water quality — its monitoring record does not meet the evidence bar.
- Typical in August
- 88°F
- Max depth
- ~37 ft est.
- Trend
- ↓ Declining
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Why Hillsborough-Calm Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Hillsborough-Calm Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by FDEP and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Hillsborough-Calm Lake is a lake in Hillsborough County, Florida with an estimated average depth of about 37 feet. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-05-06. Grade methodology: LakeQuality methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Hillsborough-Calm Lake
These readings exist but are not enough for an A–F grade — see why.
No clarity data.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples |
Where to stay near Hillsborough-Calm Lake
Compare lakeside cabins, hotels, and vacation rentals near Hillsborough-Calm Lake in Hillsborough 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 Hillsborough-Calm Lake
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Planning a whole trip? See where to stay at Florida’s top lakes →
Water Temperature
Hillsborough-Calm Lake typically sits around 88°F at the surface in August. Summer average is about 88°F. Usually warmest in Jun (about 89°F) and coldest in Dec (about 55°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 84 field readings (2010–2017) via the EPA Water Quality Portal. See the full Hillsborough-Calm Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~37 ft est. |
| Average Depth | ~10 ft est. |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Florida has not published bathymetry for Hillsborough-Calm Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Hillsborough-Calm Lake
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.664 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.44 µg/L/yr | 6 |
EPA Impairment Status
Hillsborough-Calm Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit FL1474W · Official waterbody report · Matched by proximity (1.78 km)
Graded lakes near Hillsborough-Calm Lake
Hillsborough-Calm Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Hillsborough County
Frequently asked questions about Hillsborough-Calm Lake
Where is Hillsborough-Calm Lake?
- Hillsborough-Calm Lake is a lake in Hillsborough County, Florida. LakeQuality has not rated this lake (UNRATED) — no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).
What is the water quality grade for Hillsborough-Calm Lake?
- Hillsborough-Calm Lake in Hillsborough County, Florida is not rated for water quality — its monitoring record does not meet the evidence bar.
Is Hillsborough-Calm Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Hillsborough-Calm Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Hillsborough-Calm Lake?
- Hillsborough-Calm Lake typically sits around 88°F at the surface in August, from 84 EPA Water Quality Portal field readings (2010–2017). That is a typical value for the month, not a live reading.
How deep is Hillsborough-Calm Lake?
- No published bathymetric survey covers Hillsborough-Calm Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 37 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Hillsborough-Calm Lake across LakeQuality
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Other Lakes in Florida
Where this data comes from
6 measurements from 3 monitoring stations, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- FLORIDA LAKEWATCH
21FLKWAT_WQX6 samples · 2025
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.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)