Seneca Lake is a mesotrophic lake in Yates County, New York. Water quality is graded B based on 1 sampling years through 2020. The lake supports 1 documented fish species including Brown Trout. Public access is available with 2 public boat landings. Compared to the 1 other monitored lakes in Yates County, Seneca Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, New York DNR, last sampled 2020-09-26. Grade methodology: LakeGrade methodology.
Watch Seneca Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Good clarity, visible to about 10.3 ft. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.3 ft | B |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Seneca Lake
Compare lakeside cabins, hotels, and vacation rentals near Seneca Lake in Yates County, New York — 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 Seneca Lake
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip to Seneca Lake?
Get lake water-quality report cards plus the best cabin & lodging deals near Seneca Lake — straight to your inbox. No spam, unsubscribe anytime.
Planning a whole trip? See where to stay at New York’s top lakes →
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Seneca Lake
Recreation & Access
Location
County Ranking
Ranked #2 of 2 lakes in Yates County
Cleaner Lakes Within 30 Miles
Seneca Lake holds Grade B. One nearby lake has a higher grade.
Nearby Lakes in Yates County
Explore Seneca Lake across LakeGrade
Fish species and top-graded lakes across New York
Fish species and best lakes in Yates County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Finger Lakes area
Where to stay at New York's top lakes, each with its grade
Moderate nutrients, good water quality
New York's cleanest and most-polluted lakes, ranked
More New York Lake Rankings
Other Grade B Lakes in New York
Mesotrophic Lakes in New York
More records, surveys & data sources
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.
Regulated Pollution Sources Nearby
7 EPA-permitted facilities operate within about 5 miles of Seneca Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 4 facilities have a reported Clean Water Act violation in the past three years.
- Greenidge Generation LlcDresden · 4.8 mi away · NPDES NY0001325MajorRecent violation
- Ferro Electronic MaterialsPenn Yan · 4.5 mi away · NPDES NY0002097Recent violation
- Seneca Co Sd#1 StpWillard · 4.6 mi away · NPDES NY0160407Recent violation
- Lockwood Ash Disposal SiteDresden · 4.8 mi away · NPDES NY0107069Recent violation
- Camp Seneca LakePenn Yan · 1.3 mi away · NPDES NY0081523
- Presbytery Of Geneva Camp WhitmanTorrey · 1.8 mi away · NPDES NY0159573
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.
Data Sources
Water quality data from the EPA Water Quality Portal
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Grading methodology based on Metropolitan Council standards
Public boat-access points from the USGS National Boat Ramps inventory
Most recent sample: 2020-09-26
Monitoring stations: 1