Diamond Lake
Diamond Lake in Oneida County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.5 ft visibility. Phosphorus: 25.4 µg/L. Maximum depth: 17 ft. Surface area: 117 acres.
Wisconsin DNR rates Panfish as abundant on Diamond Lake. DNR survey details →
- Clarity
- 3.5 ft
- Max depth
- 17 ft
- Area
- 117 acres
- Public access
- Yes
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Why Diamond Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Diamond Lake, 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. Sampling here has recorded water clarity and phosphorus, but not algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Diamond Lake is a 117-acre lake in Oneida County, Wisconsin with a maximum depth of 17 feet. The lake supports 5 documented fish species including Panfish, Largemouth Bass, and Smallmouth Bass. Public access is available with 3 public boat landings.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2020-07-20. Grade methodology: LakeQuality methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Diamond Lake
These readings exist but are not enough for an A–F grade — see why.
Murky, only visible to about 3.5 ft. Phosphorus level: 25.4 µg/L. Trophic State Index: 55.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.5 ft | Not graded |
| Phosphorus | 25.4 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 55 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Diamond Lake
Compare lakeside cabins, hotels, and vacation rentals near Diamond Lake in Oneida County, Wisconsin — 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 Diamond Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Wisconsin DNR rates Panfish as abundant on Diamond Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Diamond Lake — official chemistry is on file, not a letter. Catch rate is not a swim clearance and is not a weekly bite report.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2020).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 17 ft |
| Surface Area | 117 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Squirrel Lake - Kobart RoadPublic
- Squirrel Lake - Carter RoadPublic
- Diamond LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Diamond Lake
Graded lakes near Diamond Lake
Diamond Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Oneida County
Frequently asked questions about Diamond Lake
Where is Diamond Lake?
- Diamond Lake is a lake in Oneida County, Wisconsin. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Diamond Lake?
- Diamond Lake in Oneida County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.5 ft visibility. Phosphorus: 25.4 µg/L. Maximum depth: 17 ft. Surface area: 117 acres.
Is Diamond Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Diamond Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Diamond Lake?
- Diamond Lake has a maximum depth of 17 feet. The lake covers 117 acres.
What fish are in Diamond Lake?
- Fish species found in Diamond Lake include Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Diamond Lake is located in Oneida County, Wisconsin.
What did the DNR fisheries survey find at Diamond Lake?
- Wisconsin DNR rates Panfish as abundant on Diamond Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Diamond Lake — official chemistry is on file, not a letter. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Diamond Lake?
- Diamond Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Squirrel Lake - Kobart Road, Squirrel Lake - Carter Road, Diamond Lake. Public access is listed as yes.
Explore Diamond Lake across LakeQuality
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Where this data comes from
5 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX5 samples · 2020
Analytical methods
- Phosphorus by Colorimetry
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory