Rock Island Lake
Tuolumne County, California40 acresView mapDirections
No nutrient or algae sampling on record from SWRCB for this lake.
Rock Island Lake in Tuolumne County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 40 acres.
Rock Island Lake is a 40-acre lake in Tuolumne County, California.
Source: EPA Water Quality Portal sampling records, your state environmental agency. 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 Rock Island Lake is safe to swim in today is a call for the California State Water Resources Control Board and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Rock Island Lake
These are the measurements SWRCB publishes for Rock Island 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. TSI undefined.
Ask about Rock Island Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
40 acres
Shoreline
2 mi
No bathymetric survey has been published for Rock Island Lake, so its depth is not documented here.
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Frequently asked questions about Rock Island Lake
Where is Rock Island Lake?
- Rock Island Lake is a lake in Tuolumne County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of Rock Island Lake?
- Rock Island Lake in Tuolumne County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 40 acres.
Is Rock Island Lake 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 Rock Island Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.