Hillsborough-Mystik Lake
Hillsborough-Mystik Lake in Hillsborough County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 2.5 ft visibility. Phosphorus: 323.5 µg/L.
- Clarity
- 2.5 ft
- Type
- Hypereutrophic
- Trend
- ↓ Declining
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Hillsborough-Mystik Lake →
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Hillsborough-Mystik Lake is a highly nutrient-loaded hypereutrophic lake in Hillsborough County, Florida. Water quality is graded D based on 1 sampling years through 2022. Overall water quality is declining over recent sampling years. Compared to the 123 other monitored lakes in Hillsborough County, Hillsborough-Mystik Lake ranks #98 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2022-04-29. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyLimited data
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.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Very murky, less than 2.5 ft of visibility. Phosphorus level: 323.5 µg/L. Trophic State Index: 76.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.5 ft | Not graded |
| Phosphorus | 323.5 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 76 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Hillsborough-Mystik Lake
Compare lakeside cabins, hotels, and vacation rentals near Hillsborough-Mystik 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Hillsborough-Mystik Lake are listed below.
Top-rated places to stay near Hillsborough-Mystik Lake
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Planning a whole trip? See where to stay at Florida’s top lakes →
Fishing Hillsborough-Mystik Lake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.52 m/yr | 5 |
| Phosphorus | ↓ Declining | +2.55 µg/L/yr | 5 |
EPA Impairment Status
Hillsborough-Mystik 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 FL1498C · Official waterbody report · Matched by proximity (0.4 km)
County Ranking
Ranked #98 of 124 lakes in Hillsborough County
Nearby Lakes With Higher Grades
Hillsborough-Mystik Lake holds Grade D. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Hillsborough County
Frequently asked questions about Hillsborough-Mystik Lake
Where is Hillsborough-Mystik Lake?
- Hillsborough-Mystik Lake is a lake in Hillsborough County, Florida. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Hillsborough-Mystik Lake?
- Hillsborough-Mystik Lake in Hillsborough County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 2.5 ft visibility. Phosphorus: 323.5 µg/L.
Is Hillsborough-Mystik Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Hillsborough-Mystik Lake has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.
Explore Hillsborough-Mystik Lake across LakeQuality
More Florida Lake Rankings
Other Grade D Lakes in Florida
Hypereutrophic Lakes in Florida
Where this data comes from
56 measurements from 3 monitoring stations, 2021–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- FLORIDA LAKEWATCH
21FLKWAT_WQX56 samples · 2021–2022
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