Silver Island Lake
Silver Island Lake in Lake County, Minnesota has a water quality grade of A (Excellent). Water clarity: 4.4 ft visibility. Phosphorus: 22 µg/L. Chlorophyll-a (algae): 5.9 µg/L. Maximum depth: 16 ft. Surface area: 1238.88 acres.
- Clarity
- 4.4 ft
- Typical in August
- 70°F
- Max depth
- 16 ft
- Area
- 1,239 acres
- Type
- Eutrophic
- Public access
- Yes
Next lake in Lake County
Free interactive depth-contour map of Silver Island Lake, reaching a maximum surveyed depth of 15 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Silver Island Lake is a 1,239-acre productive, nutrient-rich eutrophic lake in Lake County, Minnesota with a maximum depth of 16 feet (8-foot average). Water quality is graded A based on 2 sampling years through 2025. The lake supports 11 documented fish species including black crappie, bluegill, and lake whitefish. Public access is available with 1 public boat landing. Compared to the 34 other monitored lakes in Lake County, Silver Island Lake ranks #15 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-23. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Murky, only visible to about 4.4 ft. Phosphorus level: 22 µg/L. Chlorophyll-a: 5.9 µg/L. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.4 ft | Not graded |
| Phosphorus | 22 µg/L | Good |
| Chlorophyll-a (Algae) | 5.9 µg/L | Good |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Silver Island Lake
Compare lakeside cabins, hotels, and vacation rentals near Silver Island Lake in Lake 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 Silver Island Lake
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Water Temperature
Silver Island Lake typically sits around 70°F at the surface in August. Summer average is about 69°F. Usually warmest in Aug (about 70°F) and coldest in Sep (about 63°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 27 field readings (2019–2025) via the EPA Water Quality Portal. See the full Silver Island Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 16 ft |
| Average Depth | 7.9 ft |
| Surface Area | 1,239 acres |
| Shoreline Length | 16.9 mi |
| Littoral Zone | 99% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Silver Island LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Silver Island Lake
EPA Impairment Status
Silver Island 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 MN38-0219-00 · Official waterbody report
County Ranking
Ranked #15 of 35 lakes in Lake County
Nearby Lakes in Lake County
Frequently asked questions about Silver Island Lake
What is the water quality grade for Silver Island Lake?
- Silver Island Lake in Lake County, Minnesota has a water quality grade of A (Excellent). Water clarity: 4.4 ft visibility. Phosphorus: 22 µg/L. Chlorophyll-a (algae): 5.9 µg/L. Maximum depth: 16 ft. Surface area: 1238.88 acres.
Is Silver Island Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Silver Island Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 5.9 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Silver Island Lake?
- Silver Island Lake typically sits around 70°F at the surface in August, from 27 EPA Water Quality Portal field readings (2019–2025). That is a typical value for the month, not a live reading.
How deep is Silver Island Lake?
- Silver Island Lake has a maximum depth of 16 feet and an average depth of 7.9 feet. The lake covers 1238.88 acres.
What fish are in Silver Island Lake?
- Fish species found in Silver Island Lake include black crappie, bluegill, lake whitefish, largemouth bass, northern pike, pumpkinseed, rock bass, sunfish, walleye, white sucker, yellow perch. Silver Island Lake is located in Lake County, Minnesota.
Are there boat ramps on Silver Island Lake?
- Silver Island Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Silver Island Lake. Public access is listed as yes.
Explore Silver Island Lake across LakeGrade
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Where this data comes from
16 measurements from 1 monitoring station, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA16 samples · 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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory