Second Lake
Second Lake in Clearwater County, Minnesota has a water quality grade of C (Fair). 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.
- Clarity
- 7.4 ft
- Typical in August
- 56°F
- Max depth
- 47 ft
- Area
- 72 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- Yes
Next lake in Clearwater County
Second Lake is a 72-acre mesotrophic lake in Clearwater County, Minnesota with a maximum depth of 47 feet. Water quality is graded C based on 2 sampling years through 2025. 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. Grade methodology: LakeGrade methodology.
Watch Second Lake water quality
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Moderate clarity, visible to about 7.4 ft. Phosphorus level: 21 µg/L. Chlorophyll-a: 7.8 µg/L. Trophic State Index: 49.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.4 ft | Not graded |
| Phosphorus | 21 µg/L | Good |
| Chlorophyll-a (Algae) | 7.8 µg/L | Fair |
| Trophic State Index (TSI) | 49 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay 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.
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Water Temperature
Second Lake typically sits around 56°F at the surface in August. 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.
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 →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 47 ft |
| Surface Area | 72 acres |
| Shoreline Length | 1.7 mi |
| Littoral Zone | 24% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Second LakePublic
Fishing Second Lake
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1976-07-06 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | 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, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
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
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.049 m/yr | 6 |
| Phosphorus | ↓ Declining | +1.23 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.55 µg/L/yr | 6 |
County Ranking
Ranked #31 of 37 lakes in Clearwater County
Nearby Lakes With Higher Grades
Second Lake holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Clearwater County
Frequently asked questions about Second Lake
What is the water quality grade for Second Lake?
- Second Lake in Clearwater County, Minnesota has a water quality grade of C (Fair). 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?
- Generally safe for swimming, moderate water quality. Second Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 7.8 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Second Lake?
- Second Lake typically sits around 56°F at the surface in August, 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.
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.
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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)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory