Rio Reservoir
Sullivan County, New York422 acresView mapDirections
No nutrient or algae sampling on record from NY DEC for this lake.
- Impaired · Mercury
- 34 ft max depth
Rio Reservoir in Sullivan County, New York has water-quality measurements published by NY DEC, shown here as reported. Maximum depth: 34.4 ft. Surface area: 422 acres.
Rio Reservoir is a 422-acre lake in Sullivan County, New York with a maximum depth of 34 feet.
Source: EPA Water Quality Portal sampling records, NYSDEC. Methodology: how these readings are compared.
What Rio Reservoir is good for
From access and monitoring records, not editorial picks.
- Deep water34.4 ft surveyed max depth
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Rio Reservoir is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Rio Reservoir is safe to swim in today is a call for the New York Department of Environmental Conservation and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Rio Reservoir
These are the measurements NY DEC publishes for Rio Reservoir, 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 Rio Reservoir
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
34.4 ft
Surface area
422 acres
Shoreline
8.9 mi
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Fishing Rio Reservoir
EPA Impairment Status
Rio Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Aquatic life.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NY1401-0074 · Official waterbody report
Nearby Lakes in Sullivan County
Frequently asked questions about Rio Reservoir
Where is Rio Reservoir?
- Rio Reservoir is a lake in Sullivan County, New York. Its water-quality measurements are published by NY DEC and shown on this page as reported.
What is the water quality of Rio Reservoir?
- Rio Reservoir in Sullivan County, New York has water-quality measurements published by NY DEC, shown here as reported. Maximum depth: 34.4 ft. Surface area: 422 acres.
Is Rio Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Rio Reservoir is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
How deep is Rio Reservoir?
- Rio Reservoir has a maximum depth of 34.4 feet. The lake covers 422 acres.
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Where this data comes from
Measurements for Rio Reservoir come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database