Apple River Flowage Lake
Polk County, WisconsinEutrophic
On the LakeGrade scale Apple River Flowage Lake grades a B, with clarity at 18.0 ft and 79 µg/L of phosphorus placing it above the Wisconsin median. Of the three parameters, phosphorus is the worst — at 79 µg/L of phosphorus, it keeps the lake susceptible to algal blooms in warm years.
A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. Apple River Flowage Lake reaches 18 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. Apple River Flowage Lake covers 604 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 77 graded lakes of Polk County, Apple River Flowage Lake sits at rank 59, near the bottom of the county list.
An invasive species record — Chinese Mystery Snail — has been logged at Apple River Flowage Lake; Wisconsin DNR maintains the official infested-waters list. Bass fishing is part of the appeal: the species list runs to 4, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-10-08. Grade methodology: LakeGrade methodology.
Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Crystal clear, you can see 18 ft down. Phosphorus level: 78.5 µg/L. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 18 ft | A |
| Phosphorus | 78.5 µg/L | D |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 18 ft |
| Surface Area | 604 acres |
| Public Access | Yes |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Apple River Flowage Lake (14-day solunar calendar)
→ Is it safe to eat fish from Apple River Flowage Lake? (mercury & PFAS guide)
→ Apple River Flowage Lake fishing regulations (limits, seasons, special rules)
Invasive Species
Water Quality Trend: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.079 m/yr | 6 |
| Phosphorus | ↑ Improving | -15.92 µg/L/yr | 4 |
Recreation & Access
Location
County Ranking
Ranked #59 of 77 lakes in Polk County
Cleaner Lakes Within 30 Miles
Apple River Flowage Lake holds Grade B. 5 nearby lakes hold higher grades.
- ASouth Twin LakePolk County · 1.2 mi · Higher grade (B → A)
- AKing LakePolk County · 2.4 mi · Higher grade (B → A)
- ABear Trap LakePolk County · 2.7 mi · Higher grade (B → A)
- BWapogasset LakePolk County · 3.3 mi · Higher overall water quality score
- BBlack Brook Flowage LakePolk County · 4 mi · Higher overall water quality score
Nearby Lakes in Polk County
More Wisconsin Lake Rankings
State Parks Near Apple River Flowage Lake
Other Grade B Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1986. 3 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Apple River Flowage Lake covering fish populations, stocking, water quality, and management. 1 report on file.
- 2024Apple River Flowage spring shocking survey, 2024Spring Shocking Survey · WI DNR · 2024 (PDF)
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Fish and recreation data from Wisconsin DNR Lakes
Most recent sample: 2025-10-08
Monitoring stations: 1