Where is Boulder Reservoir?

Boulder Reservoir is a lake in Boulder County, Colorado. Its water-quality measurements are published by Colorado WQCD and shown on this page as reported.

Boulder Reservoir

Boulder County, Colorado536 acresView map Directions

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

Area

536 acres

Surface area

Shoreline

4.3 mi

Measured length

Impaired · Metals (other than mercury)

See the measurements Directions Where to stay

Boulder Reservoir in Boulder County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Surface area: 536 acres.

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Boulder Reservoir is a 536-acre lake in Boulder County, Colorado.

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

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Boulder Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for metals (other than mercury). Check local advisories before you swim.

Whether Boulder 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.

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Water quality measurements for Boulder Reservoir

These are the measurements Colorado WQCD publishes for Boulder 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 Boulder Reservoir

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

Lake Details

Surface area

536 acres

Shoreline

4.3 mi

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

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Stays near Boulder Reservoir

Compare lakeside cabins, hotels, and vacation rentals near Boulder Reservoir in Boulder County, Colorado — 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 Boulder Reservoir

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Fishing Boulder Reservoir

→ Boulder Reservoir fishing regulations (limits, seasons, special rules)

EPA Impairment Status

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

Causes of impairment

Metals (other than mercury)

Designated uses not supporting: Drinking water.

Source: EPA ATTAINS assessment unit COSPSV07_B · Official waterbody report

Nearby Lakes in Boulder County

Sixmile Reservoir0.8 miView →Dodd Reservoir2.4 miView →Hayden Lake2.9 miView →Left Hand Valley Reservoir2.7 miView →Leggett and Hillcrest Reservoir4 miView →Lagerman Reservoir4.2 miView →

Frequently asked questions about Boulder Reservoir

Where is Boulder Reservoir?: Boulder Reservoir is a lake in Boulder County, Colorado. Its water-quality measurements are published by Colorado WQCD and shown on this page as reported.
What is the water quality of Boulder Reservoir?: Boulder Reservoir in Boulder County, Colorado has water-quality measurements published by Colorado WQCD, shown here as reported. Surface area: 536 acres.
Is Boulder Reservoir safe to swim in?: Nutrient and algae readings are not a swimming clearance. Boulder Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for metals (other than mercury). Check local advisories before you swim.