What is the water quality grade for Lost Valley Lake?

Lost Valley Lake in Gasconade County, Wisconsin received a water quality grade of C (Fair). Water clarity: 3.9 ft visibility. Phosphorus: 22.7 µg/L. Chlorophyll-a (algae): 7.2 µg/L. Surface area: 39 acres.

Is Lost Valley Lake safe to swim in?

Generally safe for swimming, moderate water quality. Lost Valley Lake has an overall water quality grade of C. Algae concentration (chlorophyll-a) is 7.2 µg/L. Always check local health department advisories before swimming.

Lost Valley Lake

Gasconade County, WisconsinEutrophic

Lost Valley Lake is a 39-acre productive, nutrient-rich eutrophic lake in Gasconade County, MO. Water quality is graded C based on 3 sampling years through 2022. Compared to the 3 other monitored lakes in Gasconade County, Lost Valley Lake ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2022-09-22. Grade methodology: LakeGrade methodology.

Swimming Safety

Generally safe for swimming, moderate water quality

Water Quality Grade: C, Fair

Murky, only visible to about 3.9 ft. Phosphorus level: 22.7 µg/L. Chlorophyll-a: 7.2 µg/L. Trophic State Index: 52.

Metric	Value	Grade
Water Clarity (Secchi Depth)	3.9 ft	D
Phosphorus	22.7 µg/L	B
Chlorophyll-a (Algae)	7.2 µg/L	B
Trophic State Index (TSI)	52	Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

Characteristic	Value
Surface Area	39 acres

Location

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County Ranking

Ranked #2 of 4 lakes in Gasconade County

Cleaner Lakes Within 30 Miles

Lost Valley Lake holds Grade C. 2 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Gasconade 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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Other Grade C Lakes in Wisconsin

Aspen Lake Along Southern Arm

Warren County · Clarity: 3.8 ft

Mark Twain Lake by Hwy J

Ralls County · Clarity: 3.7 ft

Red Fox Lake

Warren County · Clarity: 3.3 ft

Waukomis Lake

Platte County · Clarity: 4.7 ft

Table Rock L. Nr. Greens Hollow Lake

Barry County · Clarity: 5 ft

Little Prairie Lake by Dam

Phelps County · Clarity: 4.9 ft

Eutrophic Lakes in Wisconsin

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

Reservoir Info (USACE NID)

Lost Valley Lake is a man-made reservoir impounded by the Lost Valley Lake Dam (completed 1974), built primarily for recreation on the TR-BIG BRCH-BOEUF CREEK; earth-type dam, 30 ft tall.

Surface area: 39 ac
Normal storage: 455 ac-ft
Max storage: 626 ac-ft
Drainage area: 1,300 sq mi
Hazard class: High
Owner: RON DOLPH

Source: USACE National Inventory of Dams, NID ID MO30757 · Operator website

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2022-09-22

Monitoring stations: 2