Long Trade Lake
Long Trade Lake in Polk County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 84.8 µg/L. Maximum depth: 13 ft. Surface area: 150 acres.
Wisconsin DNR lists Panfish as common on Long Trade Lake. DNR survey details →
- Clarity
- 3 ft
- Typical in August
- 76°F
- Max depth
- 13 ft
- Area
- 150 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Long Trade Lake →
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Long Trade Lake is a 150-acre productive, nutrient-rich eutrophic lake in Polk County, Wisconsin with a maximum depth of 13 feet. Water quality is graded D based on 1 sampling years through 2026. Overall water quality is improving over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 54 other monitored lakes in Polk County, Long Trade Lake ranks #41 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-21. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyElevated nutrients
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
Water Quality Grade: D (Nutrient-rich)
Very murky, less than 3 ft of visibility. Phosphorus level: 84.8 µg/L. Trophic State Index: 65.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3 ft | Not graded |
| Phosphorus | 84.8 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 65 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Long Trade Lake
Compare lakeside cabins, hotels, and vacation rentals near Long Trade Lake in Polk 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 Long Trade Lake are listed below.
Top-rated places to stay near Long Trade 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
Long Trade Lake typically sits around 76°F at the surface in August. Summer average is about 75°F. Usually warmest in Jul (about 79°F) and coldest in Sep (about 70°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 12 field readings (2024–2025) via the EPA Water Quality Portal. See the full Long Trade Lake water temperature breakdown →
Wisconsin DNR lists Panfish as common on Long Trade Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Long Trade Lake D from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is improving. 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. Monitored by volunteers since 1986. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 13 ft |
| Surface Area | 150 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Atlas ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Long Trade 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.
Water Quality Trend: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.1 m/yr | 6 |
| Phosphorus | → Stable | -1.62 µg/L/yr | 7 |
Reservoir Info (USACE NID)
Long Trade Lake is a man-made reservoir impounded by the Atlas Feed Mill (completed 1874), built primarily for recreation on the Trade River; gravity-type dam, 14 ft tall and 92 ft long.
- Surface area
- 153 ac
- Normal storage
- 1,100 ac-ft
- Max storage
- 1,610 ac-ft
- Drainage area
- 45 sq mi
- Hazard class
- Significant
- Owner
- Polk County
All listed purposes: Recreation;Recreation;Hydroelectric.
Source: USACE National Inventory of Dams, NID ID WI00173 · Operator website
EPA Impairment Status
Long Trade Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10005131 · Official waterbody report
County Ranking
Ranked #41 of 55 lakes in Polk County
Nearby Lakes With Higher Grades
Long Trade Lake holds Grade D. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Polk County
Frequently asked questions about Long Trade Lake
Where is Long Trade Lake?
- Long Trade Lake is a lake in Polk County, Wisconsin. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Long Trade Lake?
- Long Trade Lake in Polk County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 84.8 µg/L. Maximum depth: 13 ft. Surface area: 150 acres.
Is Long Trade Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Long Trade Lake has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.
What is the water temperature of Long Trade Lake?
- Long Trade Lake typically sits around 76°F at the surface in August, from 12 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Long Trade Lake?
- Long Trade Lake has a maximum depth of 13 feet. The lake covers 150 acres.
What fish are in Long Trade Lake?
- Fish species found in Long Trade Lake include Panfish, Largemouth Bass, Northern Pike. Long Trade Lake is located in Polk County, Wisconsin.
What did the DNR fisheries survey find at Long Trade Lake?
- Wisconsin DNR lists Panfish as common on Long Trade Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Long Trade Lake D from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Long Trade Lake?
- Long Trade Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Atlas Park. Public access is listed as yes.
Explore Long Trade Lake across LakeQuality
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Where this data comes from
69 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 Resources
WIDNR_WQX69 samples · 2020–2026
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
Impairment status from EPA ATTAINS 303(d) database
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