Where is Lake Winthrop?

Lake Winthrop is a lake in Middlesex County, Massachusetts. Its water-quality measurements are published by MassDEP and shown on this page as reported.

Lake Winthrop

Middlesex County, Massachusetts132 acresView map Directions

No nutrient or algae sampling on record from MassDEP for this lake.

Area

132 acres

Surface area

Shoreline

2.5 mi

Measured length

Impaired · Algal growth

See the measurements Directions Where to stay

Lake Winthrop in Middlesex County, Massachusetts has water-quality measurements published by MassDEP, shown here as reported. Surface area: 132 acres.

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Lake Winthrop is a 132-acre lake in Middlesex County, Massachusetts.

Source: EPA Water Quality Portal sampling records, MassDEP. Methodology: how these readings are compared.

Swimming conditions

No reading

Recreation use not supported

Nutrient and algae readings are not a swimming clearance. Lake Winthrop is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, dioxins, noxious aquatic plants, nuisance exotic species. Check local advisories before you swim.

Whether Lake Winthrop is safe to swim in today is a call for the Massachusetts Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Lake Winthrop

These are the measurements MassDEP publishes for Lake Winthrop, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

No clarity data. TSI undefined.

Ask about Lake Winthrop

Answers come straight from the public measurements and survey records on this page.

Lake Details

Surface area

132 acres

Shoreline

2.5 mi

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

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Stays near Lake Winthrop

Compare lakeside cabins, hotels, and vacation rentals near Lake Winthrop in Middlesex County, Massachusetts — 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.

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Fishing Lake Winthrop

→ Lake Winthrop fishing regulations (limits, seasons, special rules)

EPA Impairment Status

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

Causes of impairment

Algal growthDioxinsNoxious aquatic plantsNuisance exotic species

Designated uses not supporting: Aquatic life, Fish consumption, Recreation, Other.

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

Source: EPA ATTAINS assessment unit MA72140 · Official waterbody report

Nearby Lakes in Middlesex County

Ashland Reservoir4.1 miView →Waushakum Pond5.2 miView →Bracket Reservoir (Number Two)6 miView →Echo Lake4.5 miView →Farm Pond19.5 ft clear5.1 miView →Farm Pond—View →

Frequently asked questions about Lake Winthrop

Where is Lake Winthrop?: Lake Winthrop is a lake in Middlesex County, Massachusetts. Its water-quality measurements are published by MassDEP and shown on this page as reported.
What is the water quality of Lake Winthrop?: Lake Winthrop in Middlesex County, Massachusetts has water-quality measurements published by MassDEP, shown here as reported. Surface area: 132 acres.
Is Lake Winthrop safe to swim in?: Nutrient and algae readings are not a swimming clearance. Lake Winthrop is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, dioxins, noxious aquatic plants, nuisance exotic species. Check local advisories before you swim.