Skip to main content
LakeQuality
C

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.

Reviewed by LakeQuality Editorial Team · Updated

Track Watap Lake

Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.

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.

MetricValueGrade
Water Clarity (Secchi Depth)9 ftC
PhosphorusNo data
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)45Mesotrophic

Moderate nutrients, good water quality

Lake Details

CharacteristicValue
Maximum Depth210 ft
Surface Area2.0K acres
Shoreline Length35.7 mi
Littoral Zone25%
Public AccessNo

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

Loading map…

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

DNR Fisheries Survey Summary

8 surveys on file from MN DNR Fisheries. Most recent: 2025-08-12 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Lake Trout9.791.36 lb
White Sucker6.861 lb
Spottail Shiner0.92
Smallmouth Bass0.720.5 lb
SCU0.170.03 lb
Fathead Minnow0.08

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

73 fish · 1040 in · 2011-09-19
24120trophy 3010121416182022242628303234363840

White Sucker

34 fish · 1220 in · 2011-09-19
1050121314151617181920

Smallmouth Bass

8 fish · 1011 in · 2011-09-19
5301011

SCU

1 fish · 44 in · 2011-09-19
104

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…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Watap Lake. 1 report on file.

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

Mercury

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