Spectacle Lake
Spectacle Lake in Isanti County, Minnesota has a water quality grade of A (Excellent). Water clarity: 13.8 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 2.2 µg/L. Maximum depth: 51.5 ft. Surface area: 246.19 acres.
- Clarity
- 13.8 ft
- Typical in August
- 76°F
- Max depth
- 51.5 ft
- Area
- 246 acres
- Type
- Oligotrophic
- Trend
- ↓ Declining
- Public access
- Yes
Next lake in Isanti County
Spectacle Lake is a 246-acre cold, clear oligotrophic lake in Isanti County, Minnesota with a maximum depth of 52 feet (9-foot average). Water quality is graded A based on 2 sampling years through 2022. Overall water quality is declining over recent sampling years. The lake supports 12 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 16 other monitored lakes in Isanti County, Spectacle Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-09-27. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLow algae
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)
Good clarity, visible to about 13.8 ft. Phosphorus level: 11 µg/L. Chlorophyll-a: 2.2 µg/L. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 13.8 ft | Not graded |
| Phosphorus | 11 µg/L | Good |
| Chlorophyll-a (Algae) | 2.2 µg/L | Good |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Spectacle Lake
Compare lakeside cabins, hotels, and vacation rentals near Spectacle Lake in Isanti 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
Spectacle Lake typically sits around 76°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 76°F) and coldest in May (about 59°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 27 field readings (2011–2021) via the EPA Water Quality Portal. See the full Spectacle Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 51.5 ft |
| Average Depth | 8.6 ft |
| Surface Area | 246 acres |
| Shoreline Length | 3.7 mi |
| Littoral Zone | 64% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Spectacle LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Spectacle Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
9 surveys on file from MN DNR Fisheries. Most recent: 2022-08-25 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| SFS | 47.52 | — |
| BNS | 42.87 | — |
| Bluegill | 38.37 | 0.1 lb |
| Bluntnose Minnow | 35.39 | — |
| MMS | 24.51 | — |
| Largemouth Bass | 11.68 | 0.99 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.
Bluegill
Largemouth Bass
From the 2022-08-25 survey
A targeted survey of the nearshore fish community in Spectacle Lake was conducted by Fisheries Index of Biological Integrity (IBI) Program Staff on 25 August 2022. Ten sampling sites were evenly spaced around the lake and each was sampled by backpack electrofishing and seining with a 15-foot or 50-foot seine, where…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Spectacle Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — SpectacleFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Spectacle (1840)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — SpectaclePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.17 m/yr | 3 |
| Phosphorus | ↑ Improving | -0.5 µg/L/yr | 3 |
| Chlorophyll-a | ↓ Declining | +0.55 µg/L/yr | 3 |
EPA Impairment Status
Spectacle Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN30-0136-00 · Official waterbody report · Matched by proximity (2.69 km)
County Ranking
Ranked #2 of 17 lakes in Isanti County
Nearby Lakes in Isanti County
Frequently asked questions about Spectacle Lake
What is the water quality grade for Spectacle Lake?
- Spectacle Lake in Isanti County, Minnesota has a water quality grade of A (Excellent). Water clarity: 13.8 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 2.2 µg/L. Maximum depth: 51.5 ft. Surface area: 246.19 acres.
Is Spectacle Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Spectacle Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 2.2 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Spectacle Lake?
- Spectacle Lake typically sits around 76°F at the surface in August, from 27 EPA Water Quality Portal field readings (2011–2021). That is a typical value for the month, not a live reading.
How deep is Spectacle Lake?
- Spectacle Lake has a maximum depth of 51.5 feet and an average depth of 8.6 feet. The lake covers 246.19 acres.
What fish are in Spectacle Lake?
- Fish species found in Spectacle Lake include black bullhead, black crappie, bluegill, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, white sucker, yellow bullhead, yellow perch. Spectacle Lake is located in Isanti County, Minnesota.
Are there boat ramps on Spectacle Lake?
- Spectacle Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Spectacle Lake. Public access is listed as yes.
Explore Spectacle Lake across LakeGrade
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Where this data comes from
50 measurements from 2 monitoring stations, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA50 samples · 2020–2022
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (2)
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