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LakeQuality

Lily Lake

NR
Not yet rated
11.5 ft clear · Mesotrophic · 217 acres
Limited DataMesotrophic

Lily Lake in Forest County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.5 ft visibility. Maximum depth: 24 ft. Surface area: 217 acres.

Clarity
11.5 ft
Typical in August
74°F
Max depth
24 ft
Area
217 acres
Trend
Stable
Public access
Yes

Next lake in Forest County

BArbutus Lake16 ft clear · Forest CountyView →
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Why Lily Lake has no grade

We grade a lake only when its monitoring record clears the evidence bar: 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 Lily 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.

Lily Lake is a 217-acre lake in Forest County, Wisconsin with a maximum depth of 24 feet. The lake supports 5 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-07-13. Grade methodology: LakeGrade 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 Lily Lake

These readings exist but do not meet the evidence bar for an A–F grade — see why.

Good clarity, visible to about 11.5 ft. Trophic State Index: 42.

MetricValueGrade
Water Clarity (Secchi Depth)11.5 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)42Mesotrophic

Moderate nutrients, good water quality

Where to stay near Lily Lake

Compare lakeside cabins, hotels, and vacation rentals near Lily Lake in Forest 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 Lily 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 →

Water Temperature

Lily Lake typically sits around 74°F at the surface in August. Summer average is about 72°F. Usually warmest in Jul (about 75°F) and coldest in May (about 61°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
61°
Jun
68°
Jul
75°
Aug
74°
Sep
66°
Oct
Nov
Dec

Typical surface water temperature by month, from 26 field readings (20252026) via the EPA Water Quality Portal. See the full Lily Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth24 ft
Surface Area217 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
28 sq mi
Shoreline
2.6 mi
Elevation
1,532 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Lily LakePublic

Fish Species

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

Fishing Lily Lake

Invasive & Introduced Species

Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.

Banded Mystery SnailRusty Crayfish

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 2009. 1 station on file (most recent sample 2025).

DNR Assessment
Excellent · Shallow Lowland lake
Trophic State Index 43 (mesotrophic) · 5-year average

Fish Species (DNR-rated)

Walleye(Abundant)Musky(Present)Panfish(Present)Largemouth Bass(Present)Northern Pike(Present)

DNR Reports & Resources

Wisconsin DNR Fisheries scientists publish multi-year survey reports for Lily Lake covering fish populations, stocking, water quality, and management. 1 report on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

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

MetricTrendChange/YearYears
Water Clarity Stable+0.089 m/yr7
See year-by-year chart →

Reservoir Info (USACE NID)

Lily Lake is a man-made reservoir impounded by the Lily Lake (completed 1976), built primarily for recreation on the LILY RIVER; earth-type dam, 7 ft tall.

Surface area
213 ac
Normal storage
600 ac-ft
Max storage
1,000 ac-ft
Drainage area
18 sq mi
Hazard class
Low
Owner
Town Of Nashville

Source: USACE National Inventory of Dams, NID ID WI12668 · Operator website

Graded lakes near Lily Lake

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

Nearby Lakes in Forest County

Frequently asked questions about Lily Lake

What is the water quality grade for Lily Lake?

Lily Lake in Forest County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.5 ft visibility. Maximum depth: 24 ft. Surface area: 217 acres.

Is Lily Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Lily Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.

What is the water temperature of Lily Lake?

Lily Lake typically sits around 74°F at the surface in August, from 26 EPA Water Quality Portal field readings (2025–2026). That is a typical value for the month, not a live reading.

How deep is Lily Lake?

Lily Lake has a maximum depth of 24 feet. The lake covers 217 acres.

What fish are in Lily Lake?

Fish species found in Lily Lake include Musky, Panfish, Largemouth Bass, Northern Pike, Walleye. Lily Lake is located in Forest County, Wisconsin.

Are there boat ramps on Lily Lake?

Lily Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lily Lake. Public access is listed as yes.

Mesotrophic Lakes in Wisconsin

Where this data comes from

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

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX75 samples · 2020–2026
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