Watap Lake
Cook County, MinnesotaLimited DataMesotrophic
The LakeGrade rubric puts Watap Lake at a C: clarity at 9.0 ft, phosphorus readings still being added, and a TSI of 45 signal an intermediate trophic state.
The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. The lake's 210 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. Watap Lake covers 1,993 acres alongside 35.7 miles of shoreline, large enough that conditions can vary meaningfully between bays. Watap Lake sits at rank 93 of 128 in Cook County, in the lower half of the local distribution.
Watap Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. 1 fish species are documented at Watap Lake, a mixed warm-water community typical for Minnesota lakes of this size. No formal public access is documented at Watap Lake — most use is by shoreline residents and their guests. 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, Minnesota DNR LakeFinder, last sampled 2024-07-30. Grade methodology: LakeGrade methodology.
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Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Moderate clarity, visible to about 9 ft. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9 ft | C |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 210 ft |
| Surface Area | 2.0K acres |
| Shoreline Length | 35.7 mi |
| Littoral Zone | 25% |
| Public Access | No |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Watap Lake (14-day solunar calendar)
→ Is it safe to eat fish from Watap Lake? (mercury & PFAS guide)
→ Watap Lake fishing regulations (limits, seasons, special rules)
Location
County Ranking
Ranked #93 of 128 lakes in Cook County
Cleaner Lakes Within 30 Miles
Watap Lake holds Grade C. 4 nearby lakes hold higher grades.
Nearby Lakes in Cook County
More Minnesota Lake Rankings
State Parks Near Watap Lake
Other Grade C Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Compare Watap Lake With Nearby Lakes
DNR Fisheries Survey Summary
8 surveys on file from MN DNR Fisheries. Most recent: 2025-08-12 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Lake Trout | 9.79 | 1.36 lb |
| White Sucker | 6.86 | 1 lb |
| Spottail Shiner | 0.92 | — |
| Smallmouth Bass | 0.72 | 0.5 lb |
| SCU | 0.17 | 0.03 lb |
| Fathead Minnow | 0.08 | — |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Lake Trout
White Sucker
Smallmouth Bass
SCU
From the 2025-08-12 survey
Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Mountain Lake on August 12th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Trout, the most sensitive coldwater species present in this lake. During the…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Watap Lake. 1 report on file.
- —Fisheries Lake Survey — MountainFisheries Lake Survey · MN DNR LakeFinder
EPA Impairment Status
Watap Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN16-0139-00 · Official waterbody report · Matched by proximity (2.68 km)
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2024-07-30
Monitoring stations: 1