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LakeQuality

Jensen Lake

C
Grade C — Fair
Fair · #19 of 45 lakes in the county · 4.6 ft clear · Eutrophic
Eutrophic

Jensen Lake in Dakota County, Minnesota has a water quality grade of C (Fair). Water clarity: 4.6 ft visibility. Phosphorus: 28 µg/L. Chlorophyll-a (algae): 12 µg/L.

Clarity
4.6 ft
Typical in August
66°F
Mean depth
~14 ft est.
Type
Eutrophic
Trend
Improving
Public access
Yes
Ice-out
Apr 4

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CEast Thomas Lake5.6 ft clear · Dakota CountyView →
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Jensen Lake is a productive, nutrient-rich eutrophic lake in Dakota County, Minnesota with an estimated average depth of about 14 feet. Water quality is graded C based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 44 other monitored lakes in Dakota County, Jensen Lake ranks #19 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-05. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Moderate

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

Compare the safest swimming lakes near St. Paul

Get alerts for Jensen Lake

Water Quality Grade: C (Fair)

Murky, only visible to about 4.6 ft. Phosphorus level: 28 µg/L. Chlorophyll-a: 12 µg/L. Trophic State Index: 54.

MetricValueGrade
Water Clarity (Secchi Depth)4.6 ftNot graded
Phosphorus28 µg/LFair
Chlorophyll-a (Algae)12 µg/LFair
Trophic State Index (TSI)54Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Jensen Lake

Compare lakeside cabins, hotels, and vacation rentals near Jensen Lake in Dakota 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 Jensen Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Minnesota’s top lakes →

Water Temperature

Jensen Lake typically sits around 66°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 78°F) and coldest in Apr (about 58°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
58°
May
67°
Jun
76°
Jul
78°
Aug
66°
Sep
68°
Oct
Nov
Dec

Typical surface water temperature by month, from 35 field readings (20172025) via the EPA Water Quality Portal. See the full Jensen Lake water temperature breakdown →

Lake Details

CharacteristicValue
Average Depth~14 ft est.
Public AccessYes

Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Jensen Lake.

Lake Size & Watershed

Watershed (drainage) area
1 sq mi
Surface area
37 acres
Mean depth (modeled estimate)
~14 ft est.
Shoreline
1.6 mi
Elevation
919 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.

Fishing Jensen Lake

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Jensen Lake. 1 report on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.107 m/yr6
Phosphorus Improving-14.21 µg/L/yr6
Chlorophyll-a Improving-13.71 µg/L/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (10 observations).

Typical Ice-Out
Apr 4
EarliestLatest
Ice-Out2016-03-13 (2016)1996-04-19 (1996)
Ice-In2023-11-24 (2023)2023-11-24 (2023)

Most recent ice-out: 2023-04-14

EPA Impairment Status

Jensen Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Nutrients (phosphorus, nitrogen)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN19-0023-00 · Official waterbody report · Matched by proximity (2.2 km)

County Ranking

Ranked #19 of 45 lakes in Dakota County

Nearby Lakes With Higher Grades

Jensen Lake holds Grade C. 2 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 Dakota County

Frequently asked questions about Jensen Lake

What is the water quality grade for Jensen Lake?

Jensen Lake in Dakota County, Minnesota has a water quality grade of C (Fair). Water clarity: 4.6 ft visibility. Phosphorus: 28 µg/L. Chlorophyll-a (algae): 12 µg/L.

Is Jensen Lake safe to swim in?

Generally safe for swimming, moderate water quality. Jensen Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 12 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Jensen Lake?

Jensen Lake typically sits around 66°F at the surface in August, from 35 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.

How deep is Jensen Lake?

No published bathymetric survey covers Jensen Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 14 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.

When does Jensen Lake thaw?

Jensen Lake typically has ice-out around Apr 4.

Where this data comes from

179 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 WaterMNPCA179 samples · 2020–2025

Analytical methods

  • Field measurement/observation, generic method
  • Total Phosphorus After Block Digestion
  • Phosphorus by Colorimetry
  • Analysis of Chlorophyll in Periphyton and Plankton
  • 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