Alta Lake
Lillooet, British ColumbiaView mapDirections
No A–F letter for this lake. The letter is scored against EPA reference conditions for a lake’s ecoregion, and those stop at the US border. Here is what has been measured.
- Limited data
Alta Lake in Lillooet, British Columbia has water-quality measurements published by ENV and no A–F letter. The letter's EPA reference conditions stop at the US border. Water clarity: 6.4 m visibility. Phosphorus: 3.7 µg/L. Chlorophyll-a (algae): 1.1 µg/L.
- Clarity
- 6.4 m
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Why Alta Lake has no A–F letter
The LakeQuality letter is scored against EPA National Lakes Assessment reference conditions for a lake’s ecoregion, and those stop at the US border. There is no reference condition for British Columbia, so the scale cannot be applied to Alta Lake at any level of sampling. Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).
This is not a gap in the monitoring record. ENV publishes these measurements directly, and everything below that has been measured is reported on this page as ENV reports it.
Monitoring: the British Columbia Ministry of Environment and Parks. Read the full grading methodology.
Alta Lake is a lake in Lillooet County, British Columbia.
Source: the British Columbia Ministry of Environment and Parks — not the EPA Water Quality Portal, last sampled 2025-10-12. Grade methodology: LakeQuality methodology.
What Alta Lake is good for
From access and monitoring records, not editorial picks.
- Clear water21 ft of visibility
Swimming Safety
Not ratedLimited data
The letter is not a swimming clearance. Check local advisories before you swim.
Water quality measurements for Alta Lake
These are the measurements ENV publishes for Alta Lake. No A–F letter applies here: see why.
Crystal clear, you can see 21 ft down. Phosphorus 3.7 µg/L. Chlorophyll-a 1.1 µg/L. TSI 29.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.4 m | Measured, not scored |
| Phosphorus | 3.7 µg/L | Measured, not scored |
| Chlorophyll-a (Algae) | 1.1 µg/L | Measured, not scored |
| Trophic State Index (TSI) | 29 | Oligotrophic |
Low nutrients, clear water. The letter is not a swimming clearance.
Fishing Alta Lake
Nearby Lakes in Lillooet
Frequently asked questions about Alta Lake
Where is Alta Lake?
- Alta Lake is a lake in Lillooet, British Columbia. Its water-quality measurements are published by ENV, and it carries no A–F letter, because no reference condition exists for lakes in this region, so the assessment thresholds behind the A–F scale cannot be applied here.
What is the water quality grade for Alta Lake?
- Alta Lake in Lillooet, British Columbia has water-quality measurements published by ENV and no A–F letter. The letter's EPA reference conditions stop at the US border. Water clarity: 6.4 m visibility. Phosphorus: 3.7 µg/L. Chlorophyll-a (algae): 1.1 µg/L.
Is Alta Lake safe to swim in?
- The letter is not a swimming clearance. Check local advisories before you swim.
Explore Alta Lake across LakeQuality
More lakes in British Columbia
Other Lakes in British Columbia
Oligotrophic Lakes in British Columbia
Where this data comes from
166 measurements from 1 monitoring station, 2017–2025. Retrieved from British Columbia EnMoDS (not the EPA Water Quality Portal) on 2026-09-06.
Collected and reported by
- British Columbia Ministry of Environment and Parks
enmods-bc166 samples · 2017–2025
Monitoring station identifiers (1)
E275784
Canadian lakes are published with the measurements their provincial programme reports, and without a LakeQuality A–F letter. The letter is scored against EPA reference conditions for a lake’s ecoregion, and the EPA does not survey these lakes. See how grades are calculated and data sources.