Isle la Motte Lake
Grade AExcellent · 15.4 ft clarity
Find places to stay →Isle la Motte Lake is a cold, clear oligotrophic lake in Clinton County, New York. Water quality is graded A based on 3 sampling years through 2024. Overall water quality is declining over recent sampling years. Compared to the 2 other monitored lakes in Clinton County, Isle la Motte Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, New York DNR, last sampled 2024-10-21. Grade methodology: LakeGrade methodology.
Watch Isle la Motte Lake water quality
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 15.4 ft down. Phosphorus level: 8.7 µg/L. Chlorophyll-a: 5 µg/L. Trophic State Index: 40.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 15.4 ft | A |
| Phosphorus | 8.7 µg/L | A |
| Chlorophyll-a (Algae) | 5 µg/L | B |
| Trophic State Index (TSI) | 40 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Isle la Motte Lake
Compare lakeside cabins, hotels, and vacation rentals near Isle la Motte Lake in Clinton 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 Isle la Motte Lake
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Fishing Isle la Motte Lake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.396 m/yr | 4 |
| Phosphorus | ↓ Declining | +0.3 µg/L/yr | 5 |
| Chlorophyll-a | ↑ Improving | -0.14 µg/L/yr | 3 |
Water Temperature
Isle la Motte Lake averages about 53°F at the surface in summer, usually warmest in Aug (about 56°F) and coldest in Apr (about 41°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 11,941 field readings (2010–2023) via the EPA Water Quality Portal. See the full Isle la Motte Lake water temperature breakdown →
Location
County Ranking
Ranked #1 of 3 lakes in Clinton County
Nearby Lakes in Clinton County
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Low nutrients, clear water, excellent for swimming
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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
1 EPA-permitted facility operate within about 5 miles of Isle la Motte Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Marine Village CottagesBeekmantown · 3.6 mi away · NPDES NY0240125Recent violation
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
Most recent sample: 2024-10-21
Monitoring stations: 1