Lake Bonaparte
Lewis County, New York1,286 acresView mapDirections
Not Rated: one monitoring station are on record, but they measured water clarity only. LakeQuality’s A–F method grades total phosphorus, total nitrogen, chlorophyll-a, and turbidity; clarity is shown, not scored.
- 52 ft max depth
- Public access
- Limited data
Lake Bonaparte in Lewis County, New York is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 15.8 ft visibility. Surface area: 1286 acres.
- Clarity
- 15.8 ft
- Max depth
- ~52 ft est.
- Area
- 1,286 acres
- Public access
- Yes
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Stays near Lake Bonaparte
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Watch Lake Bonaparte’s letter
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Why Lake Bonaparte has no grade
Lake Bonaparte has monitoring on record from one station, but only water clarity was measured. LakeQuality’s A–F letter uses total phosphorus, total nitrogen, chlorophyll-a, and turbidity against EPA National Lakes Assessment condition classes. With none of those grading measurements on record, Lake Bonaparte is Not Rated — not an F. Its 15.8-foot median from 8 readings collected 2020 is still shown as clarity, but clarity alone cannot earn a letter.
Not Rated is EPA Integrated Reporting Category 3 — insufficient information. Everything below that has been measured is still reported on this page.
Sampling is run by NYSDEC and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Lake Bonaparte is a 1,286-acre lake in Lewis County, New York with an estimated average depth of about 52 feet. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, NYSDEC, last sampled 2020-09-21. Grade methodology: LakeQuality methodology.
What Lake Bonaparte is good for
From access and monitoring records, not editorial picks.
- Clear water15.8 ft of visibility
- Boat launch1 documented ramp
- Big water1,286 acres
Swimming Safety
Not ratedLimited data
The letter is not a swimming clearance. Check local advisories before you swim.
Water quality measurements for Lake Bonaparte
These readings exist but are not enough for an A–F grade — see why.
Crystal clear, you can see 15.8 ft down. TSI 37.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 15.8 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 37 | Oligotrophic |
Low nutrients, clear water. The letter is not a swimming clearance.
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~52 ft est. |
| Average Depth | ~32 ft est. |
| Surface Area | 1,286 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. New York has not published bathymetry for Lake Bonaparte.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Lake BonapartePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Lake Bonaparte
Reservoir Info (USACE NID)
Lake Bonaparte is a man-made reservoir impounded by the Alpina Dam (completed 1933), built primarily for other on the BONAPARTE CREEK; concrete-type dam, 7 ft tall and 120 ft long.
- Surface area
- 1,286 ac
- Normal storage
- 39,739 ac-ft
- Max storage
- 39,739 ac-ft
- Drainage area
- 18.4 sq mi
- Hazard class
- Low
- Owner
- NIAGARA MOHAWK POWER CORPORATION
Source: USACE National Inventory of Dams, NID ID NY00778 · Operator website
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Lake Bonaparte under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Gouverneur Minerals Div #4 MineDiana, Town Of · 2.3 mi away · NPDES NY0110779Recent 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.
Graded lakes near Lake Bonaparte
Lake Bonaparte has no grade, but these lakes within a short drive do.
Nearby Lakes in Lewis County
Frequently asked questions about Lake Bonaparte
Where is Lake Bonaparte?
- Lake Bonaparte is a lake in Lewis County, New York. LakeQuality has not rated this lake (UNRATED) — the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity.
What is the water quality grade for Lake Bonaparte?
- Lake Bonaparte in Lewis County, New York is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 15.8 ft visibility. Surface area: 1286 acres.
Is Lake Bonaparte safe to swim in?
- The letter is not a swimming clearance. Check local advisories before you swim.
How deep is Lake Bonaparte?
- No published bathymetric survey covers Lake Bonaparte, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 52 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 1286 acres.
Are there boat ramps on Lake Bonaparte?
- Lake Bonaparte has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Bonaparte. Public access is listed as yes.
Explore Lake Bonaparte across LakeQuality
Depth, room, public access, and the state wake-sport rules
Species activity outlook by water temperature and season
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Where this data comes from
8 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North American Lake Management Society
NALMS8 samples · 2020
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory