Bonnet-Col Lake
Polk County, Florida79 acresView mapDirections
Florida DEP publishes the water-quality measurements for Bonnet-Col Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Algal growth
Bonnet-Col Lake in Polk County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 0.8 ft visibility. Phosphorus: 223 µg/L. Surface area: 79 acres.
Bonnet-Col Lake is a 79-acre highly nutrient-loaded hypereutrophic lake in Polk County, Florida. Water clarity is improving over recent sampling years. Compared to the 176 other monitored lakes in Polk County, Bonnet-Col Lake ranks #145 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-09-03. Methodology: how these readings are compared.
Swimming conditions
Readings onlyRecreation use not supported
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. Bonnet-Col Lake is listed impaired under Clean Water Act §303(d) (IR 5A) for algal growth, impaired biota (cause unknown), metals (other than mercury), nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Bonnet-Col 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 Bonnet-Col Lake
These are the measurements Florida DEP publishes for Bonnet-Col Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 0.8 ft of visibility. Phosphorus 223 µg/L. TSI 81.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 0.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 223µg/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. | 81 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Bonnet-Col Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Bonnet-Col Lake typically sits around 80°F at the surface in October. Summer average is about 84°F. Usually warmest in Jul (about 86°F) and coldest in Jan (about 63°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (63°F) to its warmest (86°F).
Typical surface water temperature by month, from 51 field readings (2010–2025) via the EPA Water Quality Portal. See the full Bonnet-Col Lake water temperature breakdown →
Lake Details
Surface area
79 acres
No bathymetric survey has been published for Bonnet-Col Lake, so its depth is not documented here.
Stays via Stay22
Stays near Bonnet-Col Lake
Compare lakeside cabins, hotels, and vacation rentals near Bonnet-Col 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Bonnet-Col Lake are listed below.
Top-rated places to stay near Bonnet-Col Lake
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Fishing Bonnet-Col Lake
Water Quality Trend: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Worsening+15.47 µg/L/yr6 years
Reservoir Info (USACE NID)
Bonnet-Col Lake is a man-made reservoir impounded by the Lake Bonnet Dam, built primarily for flood risk reduction on the Unt Itchepackesassa Creek; earth-type dam, 10 ft tall and 1,220 ft long.
- Surface area
- 79 ac
- Normal storage
- 134 ac-ft
- Max storage
- 629 ac-ft
- Drainage area
- 1.6 sq mi
- Hazard class
- High
- Owner
- MAY MANOR MHC, LLC.
All listed purposes: Flood Risk Reduction;Recreation.
Source: USACE National Inventory of Dams, NID ID FL13357 · Operator website · Matched by proximity (0.3 km)
EPA Impairment Status
Bonnet-Col Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5A).
Causes of impairment
Designated uses not supporting: Aquatic life, Recreation.
Source: EPA ATTAINS assessment unit FL1537A · Official waterbody report
Nearby Lakes in Polk County
Frequently asked questions about Bonnet-Col Lake
Where is Bonnet-Col Lake?
- Bonnet-Col Lake is a lake in Polk County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Bonnet-Col Lake?
- Bonnet-Col Lake in Polk County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 0.8 ft visibility. Phosphorus: 223 µg/L. Surface area: 79 acres.
Is Bonnet-Col Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Bonnet-Col Lake is listed impaired under Clean Water Act §303(d) (IR 5A) for algal growth, impaired biota (cause unknown), metals (other than mercury), nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Bonnet-Col Lake?
- Bonnet-Col Lake typically sits around 80°F at the surface in October, from 51 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
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Where this data comes from
48 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples48 samples · 2020–2025
Monitoring station identifiers (1)
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
Impairment status from EPA ATTAINS 303(d) database