Big Carr Lake
Oneida County, WisconsinLimited DataMesotrophic
On the LakeGrade scale Big Carr Lake grades a B, with clarity at 13.0 ft and phosphorus readings still being added placing it above the Wisconsin median. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.
A TSI near 40 places Big Carr Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. Big Carr Lake is unusually deep for Wisconsin at 75 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. At 209 acres, Big Carr Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Big Carr Lake ranks 54 of 134 in Oneida County — solidly in the upper half of the local distribution.
An invasive species record — Chinese Mystery Snail — has been logged at Big Carr Lake; Wisconsin DNR maintains the official infested-waters list. Walleye are documented at Big Carr Lake, one of 6 fish species on record for the lake. A documented public access point at Big Carr Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-08-16. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Good clarity, visible to about 13 ft. Trophic State Index: 40.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 13 ft | B |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 40 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 75 ft |
| Surface Area | 209 acres |
| Public Access | Yes |
Fish Species
Click a species to see every graded lake where it is documented.
→ Best fishing times for Big Carr Lake (14-day solunar calendar)
→ Is it safe to eat fish from Big Carr Lake? (mercury & PFAS guide)
→ Big Carr Lake fishing regulations (limits, seasons, special rules)
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Recreation & Access
Location
County Ranking
Ranked #54 of 134 lakes in Oneida County
Cleaner Lakes Within 30 Miles
Big Carr Lake holds Grade B. One nearby lake has a higher grade.
Nearby Lakes in Oneida County
More Wisconsin Lake Rankings
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
EPA Impairment Status
Big Carr Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10026824 · Official waterbody report · Matched by proximity (1.12 km)
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Fish and recreation data from Wisconsin DNR Lakes
Public boat-access points from the USGS National Boat Ramps inventory
Most recent sample: 2022-08-16
Monitoring stations: 1
Where to stay near Big Carr Lake
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