Crystal Lake
Crystal Lake in Polk County, Florida has a water quality grade of C (Fair). Water clarity: 1.6 ft visibility. Phosphorus: 44 µg/L.
- Clarity
- 1.6 ft
- Typical in July
- 87°F
- Type
- Eutrophic
- Trend
- → Stable
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Crystal Lake is a productive, nutrient-rich eutrophic lake in Polk County, Florida. Water quality is graded C based on 1 sampling years through 2023. Water clarity is improving over recent sampling years. Compared to the 176 other monitored lakes in Polk County, Crystal Lake ranks #106 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2023-10-16. 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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Very murky, less than 1.6 ft of visibility. Phosphorus level: 44 µg/L. Trophic State Index: 64.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.6 ft | Not graded |
| Phosphorus | 44 µg/L | Fair |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 64 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Crystal Lake
Compare lakeside cabins, hotels, and vacation rentals near Crystal Lake in Polk 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 Crystal Lake
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Planning a whole trip? See where to stay at Florida’s top lakes →
Water Temperature
Crystal Lake typically sits around 87°F at the surface in July. Summer average is about 86°F. Usually warmest in Jul (about 87°F) and coldest in Jan (about 63°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 44 field readings (2020–2023) via the EPA Water Quality Portal. See the full Crystal Lake water temperature breakdown →
Fishing Crystal Lake
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.016 m/yr | 6 |
| Phosphorus | ↓ Declining | +6.07 µg/L/yr | 6 |
EPA Impairment Status
Crystal Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit FL1497A · Official waterbody report
County Ranking
Ranked #106 of 177 lakes in Polk County
Nearby Lakes in Polk County
Frequently asked questions about Crystal Lake
Where is Crystal Lake?
- Crystal Lake is a lake in Polk County, Florida. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Crystal Lake?
- Crystal Lake in Polk County, Florida has a water quality grade of C (Fair). Water clarity: 1.6 ft visibility. Phosphorus: 44 µg/L.
Is Crystal Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Crystal Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.
What is the water temperature of Crystal Lake?
- Crystal Lake typically sits around 87°F at the surface in July, from 44 EPA Water Quality Portal field readings (2020–2023). That is a typical value for the month, not a live reading.
Explore Crystal Lake across LakeQuality
More Florida Lake Rankings
Other Grade C Lakes in Florida
Eutrophic Lakes in Florida
Where this data comes from
32 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples32 samples · 2020–2023
Monitoring station identifiers (1)
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