Johnstown Reservoir
Weld County, Colorado38 acresView mapDirections
No nutrient or algae sampling on record from Colorado WQCD for this lake.
Johnstown Reservoir in Weld County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Surface area: 38 acres.
Johnstown Reservoir is a 38-acre lake in Weld County, Colorado.
Source: EPA Water Quality Portal sampling records, CDPHE. 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 Johnstown Reservoir is safe to swim in today is a call for the Water Quality Control Division of the Colorado Department of Public Health and Environment and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Johnstown Reservoir
These are the measurements Colorado WQCD publishes for Johnstown 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.
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Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
38 acres
Shoreline
1.1 mi
No bathymetric survey has been published for Johnstown Reservoir, so its depth is not documented here.
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Frequently asked questions about Johnstown Reservoir
Where is Johnstown Reservoir?
- Johnstown Reservoir is a lake in Weld County, Colorado. Its water-quality measurements are published by Colorado WQCD and shown on this page as reported.
What is the water quality of Johnstown Reservoir?
- Johnstown Reservoir in Weld County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Surface area: 38 acres.
Is Johnstown 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 Johnstown Reservoir come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.