Caroline Lake
Caroline Lake in Wright County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3.5 ft visibility. Phosphorus: 53 µg/L. Chlorophyll-a (algae): 31.6 µg/L. Maximum depth: 45 ft. Surface area: 137.15 acres.
Minnesota DNR surveys at Caroline Lake average 6.57 largemouth bass per unit of sampling effort (CPUE) across 7 surveys. The most recent is a Standard Survey dated July 1, 2019. Length samples in the latest survey that recorded them ran 10–18 inches. DNR survey details →
- Clarity
- 3.5 ft
- Typical in August
- 64°F
- Max depth
- 45 ft
- Area
- 137 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- No
- Ice-out
- Apr 11
- Open water
- 234 days
Grade F measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Caroline Lake →
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Caroline Lake is a 137-acre productive, nutrient-rich eutrophic lake in Wright County, Minnesota with a maximum depth of 45 feet (15-foot average). Water quality is graded F based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 17 documented fish species including black bullhead, black crappie, and bluegill. No public access — the lake is private or restricted. Compared to the 50 other monitored lakes in Wright County, Caroline Lake ranks #39 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-10. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyAlgae risk
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.
Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom
Water Quality Grade: F (Algae-prone)
Murky, only visible to about 3.5 ft. Phosphorus level: 53 µg/L. Chlorophyll-a: 31.6 µg/L. Trophic State Index: 62.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.5 ft | Not graded |
| Phosphorus | 53 µg/L | Poor |
| Chlorophyll-a (Algae) | 31.6 µg/L | Poor |
| Trophic State Index (TSI) | 62 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Caroline Lake
Compare lakeside cabins, hotels, and vacation rentals near Caroline Lake in Wright 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Caroline Lake are listed below.
Top-rated places to stay near Caroline Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Caroline Lake typically sits around 64°F at the surface in August. Summer average is about 63°F. Usually warmest in Mar (about 69°F) and coldest in May (about 54°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 354 field readings (2010–2025) via the EPA Water Quality Portal. See the full Caroline Lake water temperature breakdown →
Minnesota DNR surveys at Caroline Lake average 6.57 largemouth bass per unit of sampling effort (CPUE) across 7 surveys. The most recent is a Standard Survey dated July 1, 2019. Length samples in the latest survey that recorded them ran 10–18 inches.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Caroline Lake F from EPA Water Quality Portal chemistry, 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
7 surveys on file from MN DNR Fisheries. Most recent: 2019-07-01 (Standard Survey).
Top Species by Catch Rate
| Species | Avg catch rate (CPUE) | Avg Weight |
|---|---|---|
| Black Bullhead | 22.24 | 0.65 lb |
| Bluegill | 13.01 | 0.22 lb |
| Black Crappie | 10.68 | 0.31 lb |
| Largemouth Bass | 6.57 | 1.65 lb |
| Northern Pike | 2.77 | 3.14 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE means more abundant in standardized sampling. This is not a weekly bite report.
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.
Black Bullhead
Bluegill
Black Crappie
Largemouth Bass
From the 2019-07-01 survey
Lake Caroline is a 126 acre lake located along the Clearwater River in Wright County east of the city of Fairhaven. The lake has a surface area of 126 acres with a maximum depth of 45 feet and a mid-summer secchi depth of 5 feet. Lake Caroline has no public access; however it can be accessed from Lake Augusta via the…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Caroline Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — CarolineFisheries Lake Survey · MN DNR LakeFinder
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 45 ft |
| Average Depth | 15 ft |
| Surface Area | 137 acres |
| Shoreline Length | 3.1 mi |
| Littoral Zone | 33% |
| 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 Caroline 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.
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.246 m/yr | 6 |
| Phosphorus | ↓ Declining | +9.64 µg/L/yr | 5 |
| Chlorophyll-a | ↓ Declining | +0.92 µg/L/yr | 5 |
Ice Season
Historical ice data from Minnesota DNR (15 observations).
Estimated open water season: 234 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2016-03-14 (2016) | 2018-04-30 (2018) |
| Ice-In | 2018-11-13 (2018) | 2015-12-19 (2015) |
Most recent ice-out: 2022-04-14
EPA Impairment Status
Caroline 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 MN86-0281-00 · Official waterbody report
County Ranking
Ranked #39 of 51 lakes in Wright County
Nearby Lakes With Higher Grades
Caroline Lake holds Grade F. 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 Wright County
Frequently asked questions about Caroline Lake
Where is Caroline Lake?
- Caroline Lake is a lake in Wright County, Minnesota. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Caroline Lake?
- Caroline Lake in Wright County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3.5 ft visibility. Phosphorus: 53 µg/L. Chlorophyll-a (algae): 31.6 µg/L. Maximum depth: 45 ft. Surface area: 137.15 acres.
Is Caroline Lake safe to swim in?
- Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Caroline Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 31.6 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Caroline Lake?
- Caroline Lake typically sits around 64°F at the surface in August, from 354 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Caroline Lake?
- Caroline Lake has a maximum depth of 45 feet and an average depth of 15 feet. The lake covers 137.15 acres.
What fish are in Caroline Lake?
- Fish species found in Caroline Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, channel catfish, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Caroline Lake is located in Wright County, Minnesota.
What did the DNR fisheries survey find at Caroline Lake?
- Minnesota DNR surveys at Caroline Lake average 6.57 largemouth bass per unit of sampling effort (CPUE) across 7 surveys. The most recent is a Standard Survey dated July 1, 2019. Length samples in the latest survey that recorded them ran 10–18 inches. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Caroline Lake F from EPA Water Quality Portal chemistry, 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.
When does Caroline Lake thaw?
- Caroline Lake typically has ice-out around Apr 11. Ice typically forms around Dec 1. The open water season is approximately 234 days.
Explore Caroline Lake across LakeQuality
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Where this data comes from
140 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA140 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 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
Ice data from Minnesota DNR Climate