St Lawrence River Lake
Leeds and Grenville Counties, OntarioView mapDirections
Ontario MECP publishes the water-quality measurements for St Lawrence River Lake. Here is what has been measured.
St Lawrence River Lake in Leeds and Grenville Counties, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 9.5 m visibility. Phosphorus: 10.1 µg/L.
St Lawrence River Lake is a lake in Leeds and Grenville Counties County, Ontario.
Source: Ontario open-data programmes (Lake Partner Program and Broad-scale Monitoring) — not the EPA Water Quality Portal, last sampled 2010-11-02. Methodology: how these readings are compared.
What St Lawrence River Lake is good for
From access and monitoring records, not editorial picks.
- Clear water31.2 ft of visibility
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether St Lawrence River Lake is safe to swim in today is a call for the Ontario Ministry of the Environment, Conservation and Parks and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for St Lawrence River Lake
These are the measurements Ontario MECP publishes for St Lawrence River Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 31.2 ft down. Phosphorus 10.1 µg/L. TSI 33.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9.5m | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10.1µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 33 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about St Lawrence River Lake
Answers come straight from the public measurements and survey records on this page.
Stays via Stay22
Stays near St Lawrence River Lake
Compare lakeside cabins, hotels, and vacation rentals near St Lawrence River Lake in Leeds and Grenville Counties, Ontario — 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 St Lawrence River Lake
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Follow St Lawrence River Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing St Lawrence River Lake
Nearby Lakes in Leeds and Grenville Counties
Frequently asked questions about St Lawrence River Lake
Where is St Lawrence River Lake?
- St Lawrence River Lake is a lake in Leeds and Grenville Counties, Ontario. Its water-quality measurements are published by Ontario MECP and shown on this page as reported.
What is the water quality of St Lawrence River Lake?
- St Lawrence River Lake in Leeds and Grenville Counties, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 9.5 m visibility. Phosphorus: 10.1 µg/L.
Is St Lawrence River Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore St Lawrence River Lake across LakeQuality
More lakes in Ontario
Other Lakes in Ontario
Oligotrophic Lakes in Ontario
Where this data comes from
Measurements for St Lawrence River Lake come from Ontario open-data programmes (Lake Partner Program and Broad-scale Monitoring), not the EPA Water Quality Portal. Per-sample source details are not recorded for this lake. Contains information licensed under the Open Government Licence – Ontario. See data sources.