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LakeQuality

Second Lake

NR
Not yet rated
3.7 ft clear · Eutrophic · 103 acres
Limited DataEutrophic

Second Lake in Oneida County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.7 ft visibility. Maximum depth: 11 ft. Surface area: 103 acres.

Wisconsin DNR lists Panfish as common on Second Lake. DNR survey details →

Clarity
3.7 ft
Max depth
11 ft
Area
103 acres
Trend
Stable

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Why Second 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 Second 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, but not phosphorus and 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.

Second Lake is a 103-acre lake in Oneida County, Wisconsin with a maximum depth of 11 feet. Water clarity is declining over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2023-08-21. Grade methodology: LakeQuality methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

Compare the safest swimming lakes near Rhinelander

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Water quality measurements for Second Lake

These readings exist but are not enough for an A–F grade — see why.

Murky, only visible to about 3.7 ft. Trophic State Index: 58.

MetricValueGrade
Water Clarity (Secchi Depth)3.7 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)58Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Second Lake

Compare lakeside cabins, hotels, and vacation rentals near Second 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 Second 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 whole trip? See where to stay at Wisconsin’s top lakes →

DNR fisheries survey

Wisconsin DNR lists Panfish as common on Second 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 Second Lake — official chemistry is on file, not a letter, and the water-quality trend over 7 years of monitoring is stable. 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 2023).

DNR Assessment
Good · Shallow Lowland lake
Trophic State Index 57 (eutrophic) · 5-year average

Fish Species (DNR-rated)

Panfish(Common)Largemouth Bass(Common)Walleye(Common)Musky(Present)Smallmouth Bass(Present)Northern Pike(Present)

Lake Details

CharacteristicValue
Maximum Depth11 ft
Surface Area103 acres

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Second Lake

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.201 m/yr7
Phosphorus Improving-0.79 µg/L/yr7
See year-by-year chart →

EPA Impairment Status

Second Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Mercury

Source: EPA ATTAINS assessment unit WI10007424 · Official waterbody report

Graded lakes near Second Lake

Second Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Oneida County

Frequently asked questions about Second Lake

Where is Second Lake?

Second 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 Second Lake?

Second Lake in Oneida County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.7 ft visibility. Maximum depth: 11 ft. Surface area: 103 acres.

Is Second Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Second 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 Second Lake?

Second Lake has a maximum depth of 11 feet. The lake covers 103 acres.

What fish are in Second Lake?

Fish species found in Second Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Second Lake is located in Oneida County, Wisconsin.

What did the DNR fisheries survey find at Second Lake?

Wisconsin DNR lists Panfish as common on Second 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 Second Lake — official chemistry is on file, not a letter, and the water-quality trend over 7 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.

Where this data comes from

19 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX19 samples · 2020–2023
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

Impairment status from EPA ATTAINS 303(d) database

Lake size & watershed from HydroLAKES (HydroSHEDS)

Fish and recreation data from Wisconsin DNR Lakes