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LakeQuality

Lake Hancock

D
Grade D — Nutrient-rich
Nutrient-rich · #143 of 177 lakes in the county · 1 ft clear · Hypereutrophic · 4,541 acres · from F
Hypereutrophic

Lake Hancock in Polk County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 1 ft visibility. Phosphorus: 265 µg/L. Surface area: 4541 acres.

Clarity
1 ft
Area
4,541 acres
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 Lake Hancock

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Lake Hancock is a 4,541-acre highly nutrient-loaded hypereutrophic lake in Polk County, Florida. Water quality is graded D based on 1 sampling years through 2025. Overall water quality is declining over recent sampling years. Compared to the 176 other monitored lakes in Polk County, Lake Hancock ranks #143 for water quality.

Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-04-21. Grade methodology: LakeQuality methodology.

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Swimming Safety

Grade only

Elevated 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

Get alerts for Lake Hancock

Water Quality Grade: D (Nutrient-rich)

Very murky, less than 1 ft of visibility. Phosphorus level: 265 µg/L. Trophic State Index: 81.

MetricValueGrade
Water Clarity (Secchi Depth)1 ftNot graded
Phosphorus265 µg/LPoor
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)81Hypereutrophic

Very high nutrients, dense algae, poor clarity

Where to stay near Lake Hancock

Compare lakeside cabins, hotels, and vacation rentals near Lake Hancock 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 Lake Hancock are listed below.

Top-rated places to stay near Lake Hancock

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Florida’s top lakes →

Lake Details

CharacteristicValue
Surface Area4,541 acres

No bathymetric survey has been published for Lake Hancock, so its depth is not documented here.

Fishing Lake Hancock

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.009 m/yr6
Phosphorus Declining+37.94 µg/L/yr6
See year-by-year chart →

Reservoir Info (USACE NID)

Lake Hancock is a man-made reservoir impounded by the P-11 (completed 1965), built primarily for flood risk reduction on the Saddle Creek; concrete-type dam, 10 ft tall and 110 ft long.

Surface area
4,541 ac
Normal storage
44,048 ac-ft
Max storage
31,787 ac-ft
Drainage area
131 sq mi
Hazard class
Significant
Owner
SWFWMD

Source: USACE National Inventory of Dams, NID ID FL13003 · Operator website

EPA Impairment Status

Lake Hancock is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).

Causes of impairment

Algal growthImpaired biota (cause unknown)Nutrients (phosphorus, nitrogen)Oxygen depletion (low DO)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit FL1623L · Official waterbody report

County Ranking

Ranked #143 of 177 lakes in Polk County

Nearby Lakes in Polk County

Frequently asked questions about Lake Hancock

Where is Lake Hancock?

Lake Hancock 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 Lake Hancock?

Lake Hancock in Polk County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 1 ft visibility. Phosphorus: 265 µg/L. Surface area: 4541 acres.

Is Lake Hancock safe to swim in?

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Lake Hancock has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.

Where this data comes from

55 measurements from 4 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Submitting organization not recorded for these samples55 samples · 2020–2025
Monitoring station identifiers (4)

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