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LakeQuality
D

Seven Hills Lake

Putnam County, WisconsinLimited DataEutrophic

Seven Hills Lake is a 56-acre productive, nutrient-rich eutrophic lake in Putnam County, NY. Water quality is graded D based on 1 sampling years through 2020. Compared to the 12 other monitored lakes in Putnam County, Seven Hills Lake ranks #12 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2020-09-14. Grade methodology: LakeGrade methodology.

Swimming Safety

Swimming not recommended, poor water quality with high algae risk

Water Quality Grade: D, Poor

Murky, only visible to about 4.8 ft. Trophic State Index: 54.

MetricValueGrade
Water Clarity (Secchi Depth)4.8 ftD
PhosphorusNo data
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)54Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Surface Area56 acres

Location

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County Ranking

Ranked #12 of 13 lakes in Putnam County

Nearby Lakes in Putnam County

A
China Pond
Putnam County
A
Indian Lake
Putnam County
B
Barrett Pond
Putnam County
C
Roaring Brook Lake
Putnam County
C
Peach Lake
Putnam County
D
Palmer Lake
Putnam 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

All Wisconsin lakes

Full state directory

Other Grade D Lakes in Wisconsin

Irondequoit Bay Lake

Monroe County · Clarity: 5.3 ft

Pleasure Lake

Sullivan County · Clarity: 4.3 ft

Fresh Pond

Suffolk County · Clarity: 6.5 ft

Duck Lake

Cayuga County · Clarity: 4.3 ft

Eagle Pond

Franklin County · Clarity: 5.2 ft

Otisco Lake

Onondaga County · Clarity: 5.2 ft

Eutrophic Lakes in Wisconsin

Irondequoit Bay LakeIrondequoit Bay LakePleasure LakeFresh Pond

Reservoir Info (USACE NID)

Seven Hills Lake is a man-made reservoir impounded by the Seven Hills Realty CO INC Dam (completed 1957), built primarily for recreation on the TR-W BRANCH CROTON RIVER; earth-type dam, 15 ft tall and 345 ft long.

Surface area
56 ac
Normal storage
380 ac-ft
Max storage
570 ac-ft
Drainage area
5.5 sq mi
Hazard class
Low
Owner
NYCDEP DAMS EAST OF THE HUDSON RIVER;SEVEN HILLS LAKE PROPERTY OWNERS ASSOC.

Source: USACE National Inventory of Dams, NID ID NY01143 · Operator website · Matched by proximity (0.62 km)

EPA Impairment Status

Seven Hills Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).

Causes of impairment

MercuryNutrients (phosphorus, nitrogen)

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

Source: EPA ATTAINS assessment unit NY1302-0045 · Official waterbody report · Matched by proximity (2.91 km)

Data Sources

Water quality data from the EPA Water Quality Portal

Impairment status from EPA ATTAINS 303(d) database

Grading methodology based on Metropolitan Council standards

Most recent sample: 2020-09-14

Monitoring stations: 1