Willis Lake
Hamilton County, New YorkView mapDirections
NY DEC publishes the water-quality measurements for Willis Lake. Here is what has been measured.
- Oligotrophic
- Limited data
Willis Lake in Hamilton County, New York has water-quality measurements published by NY DEC, shown here as reported. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 0.5 µg/L.
Willis Lake is a cold, clear oligotrophic lake in Hamilton County, New York. Overall water quality is improving over recent sampling years. Compared to the 3 other monitored lakes in Hamilton County, Willis Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, NYSDEC, last sampled 2023-07-12. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Willis Lake is safe to swim in today is a call for the New York Department of Environmental Conservation and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Willis Lake
These are the measurements NY DEC publishes for Willis 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. Phosphorus 8 µg/L. Chlorophyll-a 0.5 µg/L. TSI 29.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 8µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 0.5µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 29 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Willis Lake
Answers come straight from the public measurements and survey records on this page.
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Stays near Willis Lake
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Fishing Willis Lake
Water quality readings over time
3 seasons of samples on record (2020–2023). Calling a direction takes at least 4 years of the same measurement.
Phosphorus
Improving-0.5 µg/L/yr3 years
Chlorophyll-a
Improving-0.65 µg/L/yr3 years
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Willis Lake under Clean Water Act (NPDES) discharge permits.
- Sacandaga CampgroundWells · 2.1 mi away · NPDES NY0034371
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Hamilton County
Frequently asked questions about Willis Lake
Where is Willis Lake?
- Willis Lake is a lake in Hamilton County, New York. Its water-quality measurements are published by NY DEC and shown on this page as reported.
What is the water quality of Willis Lake?
- Willis Lake in Hamilton County, New York has water-quality measurements published by NY DEC, shown here as reported. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 0.5 µg/L.
Is Willis Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Willis Lake across LakeQuality
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Where this data comes from
6 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- USGS New York Water Science Center
USGS-NY6 samples · 2020–2023
Analytical methods
- P, wu, WCA, persulfate CF color
- Chlorophyll a,fluorometric,uncor
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)