Bonnet-Col Lake
Bonnet-Col Lake in Polk County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 0.8 ft visibility. Phosphorus: 223 µg/L. Surface area: 79 acres.
- Clarity
- 0.8 ft
- Typical in August
- 85°F
- Area
- 79 acres
- Type
- Hypereutrophic
- Trend
- → Stable
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Bonnet-Col Lake →
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Bonnet-Col Lake is a 79-acre highly nutrient-loaded hypereutrophic lake in Polk County, Florida. Water quality is graded D based on 1 sampling years through 2025. 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. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyElevated nutrients
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 0.8 ft of visibility. Phosphorus level: 223 µg/L. Trophic State Index: 81.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 0.8 ft | Not graded |
| Phosphorus | 223 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 81 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay 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 grade measures 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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Planning a whole trip? See where to stay at Florida’s top lakes →
Water Temperature
Bonnet-Col Lake typically sits around 85°F at the surface in August. 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.
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
| Characteristic | Value |
|---|---|
| Surface Area | 79 acres |
No bathymetric survey has been published for Bonnet-Col Lake, so its depth is not documented here.
Fishing Bonnet-Col Lake
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.12 m/yr | 6 |
| Phosphorus | ↓ Declining | +15.47 µg/L/yr | 6 |
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
Source: EPA ATTAINS assessment unit FL1537A · Official waterbody report · Matched by proximity (0.84 km)
County Ranking
Ranked #145 of 177 lakes in Polk County
Nearby Lakes With Higher Grades
Bonnet-Col Lake holds Grade D. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →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. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Bonnet-Col Lake?
- Bonnet-Col Lake in Polk County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 0.8 ft visibility. Phosphorus: 223 µg/L. Surface area: 79 acres.
Is Bonnet-Col 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. Bonnet-Col Lake has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.
What is the water temperature of Bonnet-Col Lake?
- Bonnet-Col Lake typically sits around 85°F at the surface in August, from 51 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
Explore Bonnet-Col Lake across LakeQuality
More Florida Lake Rankings
Other Grade D Lakes in Florida
Hypereutrophic Lakes in Florida
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)
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