Second Lake
Clearwater County, Minnesota72 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Second Lake. Here is what has been measured.
- Mesotrophic
- 47 ft max depth
- Public access
Second Lake in Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 7.4 ft visibility. Phosphorus: 21 µg/L. Chlorophyll-a (algae): 7.8 µg/L. Maximum depth: 47 ft. Surface area: 72.29 acres.
Minnesota DNR's Standard Survey on July 6, 1976 caught 1.25 walleye per gill net at Second Lake. DNR survey details →
Second Lake is a 72-acre mesotrophic lake in Clearwater County, Minnesota with a maximum depth of 47 feet. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 36 other monitored lakes in Clearwater County, Second Lake ranks #31 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-09. Methodology: how these readings are compared.
What Second Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Deep water47 ft surveyed max depth
Swimming conditions
Readings onlyModerate algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Second Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Second Lake
These are the measurements Minnesota PCA publishes for Second Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 7.4 ft. Phosphorus 21 µg/L. Chlorophyll-a 7.8 µg/L. TSI 49.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 7.4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 21µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 7.8µg/L | Fair GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 49 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Second Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Second Lake typically sits around 54°F at the surface in September. Summer average is about 55°F. Usually warmest in Jul (about 56°F) and coldest in May (about 46°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (46°F) to its warmest (56°F).
Typical surface water temperature by month, from 115 field readings (2010–2025) via the EPA Water Quality Portal. See the full Second Lake water temperature breakdown →
Minnesota DNR's Standard Survey on July 6, 1976 caught 1.25 walleye per gill net at Second Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Second Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1976-07-06 (Standard Survey).
1 survey on file · most recent 1976-07-06 (Standard Survey)
50 years old| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Brown Bullhead | 90.04 | 0.16 lb | |
| Yellow Perch | 30.41 | 0.15 lb | |
| White Sucker | 5.79 | 1.21 lb | |
| Northern Pike | 1.54 | 2.06 lb | |
| Walleye | 1.25 | 2.32 lb | |
| Black Crappie | 0.67 | 0.8 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
From the 1976-07-06 survey
Bullheads, Suckers and Perch dominate the fishery and are below average in size. N Pike and Blk Crappies are present in moderate numbers. Walleye are present in small numbers.
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Second Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — SecondFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Second (1706)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — SecondPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
47 ft
Surface area
72 acres
Shoreline
1.7 mi
Littoral zone
24%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
27 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,427 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Second LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Second Lake
Compare lakeside cabins, hotels, and vacation rentals near Second Lake in Clearwater County, Minnesota — 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.
Top-rated places to stay near Second Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 Minnesota’s top lakes →
Follow Second Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Second Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Worsening+1.23 µg/L/yr6 years
Chlorophyll-a
Worsening+0.55 µg/L/yr6 years
Nearby Lakes in Clearwater County
Frequently asked questions about Second Lake
Where is Second Lake?
- Second Lake is a lake in Clearwater County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Second Lake?
- Second Lake in Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 7.4 ft visibility. Phosphorus: 21 µg/L. Chlorophyll-a (algae): 7.8 µg/L. Maximum depth: 47 ft. Surface area: 72.29 acres.
Is Second Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Second Lake?
- Second Lake typically sits around 54°F at the surface in September, from 115 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Second Lake?
- Second Lake has a maximum depth of 47 feet. The lake covers 72.29 acres.
What did the DNR fisheries survey find at Second Lake?
- Minnesota DNR's Standard Survey on July 6, 1976 caught 1.25 walleye per gill net at Second Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Second Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Second Lake?
- Second Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Second Lake. Public access is listed as yes.
Can I fish at Second Lake?
- Second Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Second Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Clearwater County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Mississippi Headwaters, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Second Lake
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
27 measurements from 1 monitoring station, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA27 samples · 2024–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory