Sully Lake is a lake in Sully County, South Dakota. Its water-quality measurements are published by SD DANR and shown on this page as reported.

Sully Lake

Sully County, South Dakota212 acresView map Directions

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

Area

212 acres

Surface area

Shoreline

4.8 mi

Measured length

Impaired · Algal growth
Limited data

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Sully Lake in Sully County, South Dakota has water-quality measurements published by SD DANR, shown here as reported. Surface area: 212 acres.

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Sully Lake is a 212-acre lake in Sully County, South Dakota.

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

Swimming conditions

No reading

Recreation use not supported

Nutrient and algae readings are not a swimming clearance. Sully Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.

Whether Sully Lake is safe to swim in today is a call for the South Dakota Department of Agriculture and Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Sully Lake

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

No clarity data.

Ask about Sully Lake

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

Lake Details

Surface area

212 acres

Shoreline

4.8 mi

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

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Stays near Sully Lake

Compare lakeside cabins, hotels, and vacation rentals near Sully Lake in Sully County, South Dakota — 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.

Top-rated places to stay near Sully Lake

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Fishing Sully Lake

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

EPA Impairment Status

Sully Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Algal growth

Designated uses not supporting: Aquatic life, Recreation.

Source: EPA ATTAINS assessment unit SD-MI-L-SULLY_01 · Official waterbody report

Nearby Lakes in Sully County

Warnes Slough8.2 miView →Fuller Lake12.5 miView →Lake Okobojo12.5 miView →Post Lake15 miView →Cottonwood Lake15.9 miView →Durrstein Lake19.6 miView →

Frequently asked questions about Sully Lake

Where is Sully Lake?: Sully Lake is a lake in Sully County, South Dakota. Its water-quality measurements are published by SD DANR and shown on this page as reported.
What is the water quality of Sully Lake?: Sully Lake in Sully County, South Dakota has water-quality measurements published by SD DANR, shown here as reported. Surface area: 212 acres.
Is Sully Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Sully Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.