Friendship Lake
Friendship Lake in Adams County, Wisconsin has a water quality grade of C (Fair). Water clarity: 4 ft visibility. Phosphorus: 31 µg/L. Maximum depth: 15 ft. Surface area: 125 acres.
- Clarity
- 4 ft
- Typical in August
- 74°F
- Max depth
- 15 ft
- Area
- 125 acres
- Type
- Eutrophic
- Trend
- → Stable
- Public access
- Yes
Next lake in Adams County
Friendship Lake is a 125-acre productive, nutrient-rich eutrophic lake in Adams County, Wisconsin with a maximum depth of 15 feet. Water quality is graded C based on 1 sampling years through 2026. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 17 other monitored lakes in Adams County, Friendship Lake ranks #16 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-23. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 4 ft. Phosphorus level: 31 µg/L. Trophic State Index: 55.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4 ft | Not graded |
| Phosphorus | 31 µg/L | Fair |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 55 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Friendship Lake
Compare lakeside cabins, hotels, and vacation rentals near Friendship Lake in Adams 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.
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Water Temperature
Friendship Lake typically sits around 74°F at the surface in August. Summer average is about 69°F. Usually warmest in Aug (about 74°F) and coldest in Jun (about 64°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 38 field readings (2024–2026) via the EPA Water Quality Portal. See the full Friendship Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 15 ft |
| Surface Area | 125 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Friendship LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Friendship 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.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1994. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Water Quality Trend: → Stable
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.018 m/yr | 7 |
| Phosphorus | → Stable | +0.18 µg/L/yr | 7 |
Reservoir Info (USACE NID)
Friendship Lake is a man-made reservoir impounded by the Friendship (completed 1928), built primarily for recreation; gravity-type dam, 22 ft tall and 400 ft long.
- Surface area
- 114 ac
- Normal storage
- 681 ac-ft
- Max storage
- 1,000 ac-ft
- Drainage area
- 60 sq mi
- Hazard class
- Significant
- Owner
- Friendship Lake District
All listed purposes: Recreation;Hydroelectric.
Source: USACE National Inventory of Dams, NID ID WI00061 · Operator website
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Friendship Lake under Clean Water Act (NPDES) discharge permits. 2 facilities have a reported Clean Water Act violation in the past three years.
- Adams Wastewater Treatment FacilityFriendship · 1 mi away · NPDES WI0023159Recent violation
- Grande Cheese Co Food IngredieFriendship · 1.3 mi away · NPDES WI0050547Recent 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 #16 of 18 lakes in Adams County
Nearby Lakes With Higher Grades
Friendship Lake holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Adams County
Frequently asked questions about Friendship Lake
What is the water quality grade for Friendship Lake?
- Friendship Lake in Adams County, Wisconsin has a water quality grade of C (Fair). Water clarity: 4 ft visibility. Phosphorus: 31 µg/L. Maximum depth: 15 ft. Surface area: 125 acres.
Is Friendship Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Friendship Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.
What is the water temperature of Friendship Lake?
- Friendship Lake typically sits around 74°F at the surface in August, from 38 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is Friendship Lake?
- Friendship Lake has a maximum depth of 15 feet. The lake covers 125 acres.
What fish are in Friendship Lake?
- Fish species found in Friendship Lake include Panfish, Largemouth Bass, Northern Pike, Walleye. Friendship Lake is located in Adams County, Wisconsin.
Are there boat ramps on Friendship Lake?
- Friendship Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Friendship Lake. Public access is listed as yes.
Explore Friendship Lake across LakeGrade
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Where this data comes from
85 measurements from 2 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX85 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (2)
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