What is the water quality grade for Rocky Fork Lake?

Rocky Fork Lake in Boone County, Wisconsin received a water quality grade of F (Very Poor). Water clarity: 2.3 ft visibility. Phosphorus: 73.8 µg/L. Chlorophyll-a (algae): 38.1 µg/L. Surface area: 55 acres.

Is Rocky Fork Lake safe to swim in?

Avoid swimming, very poor water quality, potential algae toxins. Rocky Fork Lake has an overall water quality grade of F. Algae concentration (chlorophyll-a) is 38.1 µg/L. Always check local health department advisories before swimming.

Rocky Fork Lake

Boone County, WisconsinEutrophic

Rocky Fork Lake is a 55-acre productive, nutrient-rich eutrophic lake in Boone County, MO. Water quality is graded F based on 3 sampling years through 2023. Compared to the 11 other monitored lakes in Boone County, Rocky Fork Lake ranks #9 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2023-08-30. Grade methodology: LakeGrade methodology.

Swimming Safety

Avoid swimming, very poor water quality, potential algae toxins

Water Quality Grade: F, Very Poor

Very murky, less than 2.3 ft of visibility. Phosphorus level: 73.8 µg/L. Chlorophyll-a: 38.1 µg/L. Trophic State Index: 66.

Metric	Value	Grade
Water Clarity (Secchi Depth)	2.3 ft	F
Phosphorus	73.8 µg/L	D
Chlorophyll-a (Algae)	38.1 µg/L	F
Trophic State Index (TSI)	66	Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

Characteristic	Value
Surface Area	55 acres

Location

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County Ranking

Ranked #9 of 12 lakes in Boone County

Cleaner Lakes Within 30 Miles

Rocky Fork Lake holds Grade F. 5 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Boone County

More Wisconsin Lake Rankings

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Top 25 by overall water quality score

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Grade A/B + low algae filter

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Panfish-rich, public access

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Other Grade F Lakes in Wisconsin

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St. Louis County · Clarity: 1.6 ft

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Jackson County · Clarity: 2 ft

Lake St. Louis by Dam

St. Charles County · Clarity: 2.3 ft

Hemitite Lake

St. Francois County · Clarity: 1.1 ft

Blind Pony Lake

Saline County · Clarity: 2.3 ft

Stockton Lake Upstream of Hwy 123 Bridge

Polk County · Clarity: 1.2 ft

Eutrophic Lakes in Wisconsin

Aspen Lake Along Southern Arm Boathouse Lake Hunnewell Lake Long Branch Lk. Lake

Reservoir Info (USACE NID)

Rocky Fork Lake is a man-made reservoir impounded by the Rocky Fork Creek Dam (completed 1965), built primarily for other on the ROCKY FORK CREEK; earth-type dam, 15 ft tall.

Surface area: 55 ac
Normal storage: 275 ac-ft
Max storage: 441 ac-ft
Drainage area: 55 sq mi
Hazard class: Low
Owner: MO DEPT OF CONSERVATION

All listed purposes: Other;Recreation.

Source: USACE National Inventory of Dams, NID ID MO10844 · Operator website · Matched by proximity (0.13 km)

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2023-08-30

Monitoring stations: 1