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LakeQuality

Forestville Millpond

D
Grade D — Nutrient-rich
Nutrient-rich · #5 of 5 lakes in the county · 3 ft clear · Eutrophic · 65 acres · from F
Limited DataEutrophic

Forestville Millpond in Door County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 94.3 µg/L. Maximum depth: 5 ft. Surface area: 65 acres.

Clarity
3 ft
Max depth
5 ft
Area
65 acres
Type
Eutrophic
Trend
Declining
Public access
Yes

Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Forestville Millpond

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BDunes Lake4 ft clear · Door CountyView →
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Forestville Millpond is a 65-acre productive, nutrient-rich eutrophic lake in Door County, Wisconsin with a maximum depth of 5 feet. Water quality is graded D based on 1 sampling years through 2023. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Smallmouth Bass. Public access is available with 1 public boat landing. Compared to the 4 other monitored lakes in Door County, Forestville Millpond ranks #5 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2023-08-16. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Limited data

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum

Compare the safest swimming lakes near Green Bay

Get alerts for Forestville Millpond

Water Quality Grade: D (Nutrient-rich)

Very murky, less than 3 ft of visibility. Phosphorus level: 94.3 µg/L. Trophic State Index: 66.

MetricValueGrade
Water Clarity (Secchi Depth)3 ftNot graded
Phosphorus94.3 µg/LPoor
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)66Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Forestville Millpond

Compare lakeside cabins, hotels, and vacation rentals near Forestville Millpond in Door 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Forestville Millpond are listed below.

Top-rated places to stay near Forestville Millpond

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 →

Lake Details

CharacteristicValue
Maximum Depth5 ft
Surface Area65 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
51 sq mi
Shoreline
2.6 mi
Elevation
604 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Forestville Dam ParkPublic

Fish Species

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

Fishing Forestville Millpond

Invasive & Introduced Species

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

Curly-Leaf PondweedEurasian Water-Milfoil

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 2005. 3 stations on file (most recent sample 2025).

Fish Species (DNR-rated)

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

DNR Reports & Resources

Wisconsin DNR Fisheries scientists publish multi-year survey reports for Forestville Millpond 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 4 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.449 m/yr4
See year-by-year chart →

Reservoir Info (USACE NID)

Forestville Millpond is a man-made reservoir impounded by the Forestville (completed 1877), built primarily for recreation on the AHNAPEE RIVER; earth-type dam, 10 ft tall and 1,200 ft long.

Surface area
72 ac
Normal storage
170 ac-ft
Max storage
300 ac-ft
Drainage area
31 sq mi
Hazard class
Low
Owner
Door County

Source: USACE National Inventory of Dams, NID ID WI00256 · Operator website · Matched by proximity (0.06 km)

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Forestville Millpond under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.

  • Forestville Wastewater Treatment Facility
    Forestville · 0.9 mi away · NPDES WI0028894
    Recent 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.

County Ranking

Ranked #5 of 5 lakes in Door County

Nearby Lakes With Higher Grades

Forestville Millpond holds Grade D. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

Nearby Lakes in Door County

Frequently asked questions about Forestville Millpond

What is the water quality grade for Forestville Millpond?

Forestville Millpond in Door County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 94.3 µg/L. Maximum depth: 5 ft. Surface area: 65 acres.

Is Forestville Millpond safe to swim in?

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Forestville Millpond has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.

How deep is Forestville Millpond?

Forestville Millpond has a maximum depth of 5 feet. The lake covers 65 acres.

What fish are in Forestville Millpond?

Fish species found in Forestville Millpond include Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike. Forestville Millpond is located in Door County, Wisconsin.

Are there boat ramps on Forestville Millpond?

Forestville Millpond has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Forestville Dam Park. Public access is listed as yes.

Where this data comes from

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

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX20 samples · 2023

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

Regulated discharger data from EPA ECHO (ICIS-NPDES)

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