Lake Henry
Lake Henry in Polk County, Florida is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 1.3 ft visibility. Phosphorus: 119.5 µg/L. Surface area: 861 acres.
- Clarity
- 1.3 ft
- Area
- 861 acres
- Trend
- ↑ Improving
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Why Lake Henry 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 Lake Henry, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity and phosphorus, but not algae (chlorophyll-a).
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.
Lake Henry is a 861-acre lake in Polk County, Florida. Overall water quality is improving over recent sampling years.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2022-11-09. 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 Lake Henry
These readings exist but are not enough for an A–F grade — see why.
Very murky, less than 1.3 ft of visibility. Phosphorus level: 119.5 µg/L. Trophic State Index: 73.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.3 ft | Not graded |
| Phosphorus | 119.5 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 73 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Lake Henry
Compare lakeside cabins, hotels, and vacation rentals near Lake Henry 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 Lake Henry
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 861 acres |
No bathymetric survey has been published for Lake Henry, so its depth is not documented here.
Fishing Lake Henry
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.1 m/yr | 4 |
| Phosphorus | ↑ Improving | -15.15 µg/L/yr | 4 |
Reservoir Info (USACE NID)
Lake Henry is a man-made reservoir impounded by the P-5 (completed 1964), built primarily for flood risk reduction on the P5 Canal; concrete-type dam, 33 ft tall and 60 ft long.
- Surface area
- 861 ac
- Normal storage
- 5,166 ac-ft
- Max storage
- 12,312 ac-ft
- Drainage area
- 4.3 sq mi
- Hazard class
- Significant
- Owner
- SWFWMD
Source: USACE National Inventory of Dams, NID ID FL12012 · Operator website
EPA Impairment Status
Lake Henry is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5A).
Causes of impairment
Source: EPA ATTAINS assessment unit FL15002 · Official waterbody report · Matched by proximity (2.22 km)
Graded lakes near Lake Henry
Lake Henry has no grade, but these lakes within a short drive do.
Nearby Lakes in Polk County
Frequently asked questions about Lake Henry
Where is Lake Henry?
- Lake Henry is a lake in Polk 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 Lake Henry?
- Lake Henry in Polk County, Florida is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 1.3 ft visibility. Phosphorus: 119.5 µg/L. Surface area: 861 acres.
Is Lake Henry safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Lake Henry is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
Explore Lake Henry across LakeQuality
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Where this data comes from
8 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples8 samples · 2022
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