Alden Lake
Alden Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5 ft visibility. Maximum depth: 29 ft. Surface area: 189.7 acres.
- Clarity
- 5 ft
- Typical in August
- 71°F
- Max depth
- 29 ft
- Area
- 190 acres
- Trend
- → Stable
- Public access
- No
Next lake in St. Louis County
Why Alden Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Alden Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Alden Lake is a 190-acre lake in St. Louis County, Minnesota with a maximum depth of 29 feet (6-foot average). The lake supports 11 documented fish species including black crappie, bluegill, and largemouth bass. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Alden Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Murky, only visible to about 5 ft. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Alden Lake
Compare lakeside cabins, hotels, and vacation rentals near Alden Lake in St. Louis 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 Alden Lake
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Water Temperature
Alden Lake typically sits around 71°F at the surface in August. Summer average is about 70°F. Usually warmest in Jul (about 72°F) and coldest in May (about 60°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 36 field readings (2022–2025) via the EPA Water Quality Portal. See the full Alden Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 29 ft |
| Average Depth | 6 ft |
| Surface Area | 190 acres |
| Shoreline Length | 4.1 mi |
| Littoral Zone | 84% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Alden Lake
DNR Fisheries Survey Summary
3 surveys on file from MN DNR Fisheries. Most recent: 2001-07-30 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Yellow Perch | 5.18 | 0.15 lb |
| White Sucker | 4.40 | 2.48 lb |
| Smallmouth Bass | 2.31 | 1.17 lb |
| Walleye | 1.77 | 1.97 lb |
| Bluegill | 1.60 | 0.25 lb |
| Shorthead Redhorse | 1.38 | 1.92 lb |
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.
Yellow Perch
White Sucker
Smallmouth Bass
Walleye
From the 2001-07-30 survey
Big Alden is a 180 acre lake with 159 (88%) acres of littoral area and a maximum depth of 29 feet . Big Alden Lake is located 14 miles northeast of Duluth off St. Louis County Highway #44. Big Alden does not have a developed public access along the shoreline but can be accessed by canoe through the Cloquet River. The…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Alden Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — AldenFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Alden (0536)Aquatic Plant Report · MN DNR LakeFinder
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.028 m/yr | 6 |
EPA Impairment Status
Alden Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN69-0131-00 · Official waterbody report
Nearby Lakes in St. Louis County
Frequently asked questions about Alden Lake
What is the water quality grade for Alden Lake?
- Alden Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5 ft visibility. Maximum depth: 29 ft. Surface area: 189.7 acres.
Is Alden Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Alden Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Alden Lake?
- Alden Lake typically sits around 71°F at the surface in August, from 36 EPA Water Quality Portal field readings (2022–2025). That is a typical value for the month, not a live reading.
How deep is Alden Lake?
- Alden Lake has a maximum depth of 29 feet and an average depth of 6 feet. The lake covers 189.7 acres.
What fish are in Alden Lake?
- Fish species found in Alden Lake include black crappie, bluegill, largemouth bass, northern pike, pumpkinseed, rock bass, shorthead redhorse, smallmouth bass, walleye, white sucker, yellow perch. Alden Lake is located in St. Louis County, Minnesota.
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Where this data comes from
62 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA62 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder