Cornwell Reservoir
Valley County, Montana43 acresView mapDirections
No nutrient or algae sampling on record from Montana DEQ for this lake.
Cornwell Reservoir in Valley County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Surface area: 43 acres.
Cornwell Reservoir is a 43-acre lake in Valley County, Montana.
Source: EPA Water Quality Portal sampling records, Montana DEQ. Methodology: how these readings are compared.
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Cornwell Reservoir is safe to swim in today is a call for the Montana Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Cornwell Reservoir
These are the measurements Montana DEQ publishes for Cornwell 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 Cornwell Reservoir
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
43 acres
Shoreline
1.5 mi
No bathymetric survey has been published for Cornwell Reservoir, so its depth is not documented here.
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Frequently asked questions about Cornwell Reservoir
Where is Cornwell Reservoir?
- Cornwell Reservoir is a lake in Valley County, Montana. Its water-quality measurements are published by Montana DEQ and shown on this page as reported.
What is the water quality of Cornwell Reservoir?
- Cornwell Reservoir in Valley County, Montana has water-quality measurements published by Montana DEQ, shown here as reported. Surface area: 43 acres.
Is Cornwell Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
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Where this data comes from
Measurements for Cornwell Reservoir come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.