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LakeQuality

Langdon Lake

NR
Not yet rated
1.5 ft clear · Hypereutrophic · 143 acres
Limited DataHypereutrophic

Langdon Lake in Hennepin County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 1.5 ft visibility. Maximum depth: 38 ft. Surface area: 143.34 acres.

Clarity
1.5 ft
Typical in August
68°F
Max depth
38 ft
Area
143 acres
Trend
Improving
Public access
Yes
Ice-out
Mar 31
Open water
237 days

Next lake in Hennepin County

CLittle Long Lake18.7 ft clear · Hennepin CountyView →
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Why Langdon 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 Langdon 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.

Langdon Lake is a 143-acre lake in Hennepin County, Minnesota with a maximum depth of 38 feet. Overall water quality is improving over recent sampling years. The lake supports 8 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 2 public boat landings.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-11-23. Grade methodology: LakeGrade methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

Compare the safest swimming lakes near Minneapolis

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Water quality measurements for Langdon Lake

These readings exist but do not meet the evidence bar for an A–F grade — see why.

Very murky, less than 1.5 ft of visibility. Trophic State Index: 71.

MetricValueGrade
Water Clarity (Secchi Depth)1.5 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)71Hypereutrophic

Very high nutrients, dense algae, poor clarity

Where to stay near Langdon Lake

Compare lakeside cabins, hotels, and vacation rentals near Langdon Lake in Hennepin 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 Langdon 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

Langdon Lake typically sits around 68°F at the surface in August. Summer average is about 67°F. Usually warmest in Jul (about 70°F) and coldest in Mar (about 41°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
41°
Apr
49°
May
55°
Jun
64°
Jul
70°
Aug
68°
Sep
64°
Oct
55°
Nov
43°
Dec

Typical surface water temperature by month, from 325 field readings (20102024) via the EPA Water Quality Portal. See the full Langdon Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth38 ft
Surface Area143 acres
Shoreline Length2.1 mi
Littoral Zone58%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
1 sq mi
Elevation
919 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Lake Minnetonka, Phelp'sPublic
  • Lake Minnetonka, Mounds Bay ParkPublic

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Langdon 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.

Eurasian watermilfoil

DNR Fisheries Survey Summary

2 surveys on file from MN DNR Fisheries. Most recent: 1993-07-06 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Fathead Minnow622.33
Black Bullhead120.590.83 lb
BST36.33
Northern Pike7.702.75 lb
Bluegill4.550.16 lb
Green Sunfish3.430.14 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.

Black Bullhead

876 fish · 411 in · 1993-07-06
30615304567891011

Bluegill

150 fish · 17 in · 1993-07-06
713601234567

Green Sunfish

54 fish · 25 in · 1993-07-06
281402345

From the 1993-07-06 survey

Black bullhead are by far the most common species found in Langdon lake. Their population is considered high for lake class 38, and they are of above average weight. Green sunfish were also found to be very abundant, but are mainly 3.5 to 5 inches in length. Bluegill numbers are average for this lake class. Of 79 fish…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Langdon 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 Improving+0.131 m/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (8 observations).

Typical Ice-Out
Mar 31
Typical Ice-In
Nov 23

Estimated open water season: 237 days

EarliestLatest
Ice-Out2017-03-07 (2017)2023-04-14 (2023)
Ice-In2022-11-19 (2022)2024-11-30 (2024)

Most recent ice-out: 2023-04-14

EPA Impairment Status

Langdon 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 MN27-0182-00 · Official waterbody report

Graded lakes near Langdon Lake

Langdon Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Hennepin County

Frequently asked questions about Langdon Lake

What is the water quality grade for Langdon Lake?

Langdon Lake in Hennepin County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 1.5 ft visibility. Maximum depth: 38 ft. Surface area: 143.34 acres.

Is Langdon Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Langdon 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 Langdon Lake?

Langdon Lake typically sits around 68°F at the surface in August, from 325 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.

How deep is Langdon Lake?

Langdon Lake has a maximum depth of 38 feet. The lake covers 143.34 acres.

What fish are in Langdon Lake?

Fish species found in Langdon Lake include black bullhead, black crappie, bluegill, brown bullhead, green sunfish, hybrid sunfish, pumpkinseed, yellow bullhead. Langdon Lake is located in Hennepin County, Minnesota.

When does Langdon Lake thaw?

Langdon Lake typically has ice-out around Mar 31. Ice typically forms around Nov 23. The open water season is approximately 237 days.

Are there boat ramps on Langdon Lake?

Langdon Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Lake Minnetonka, Phelp's, Lake Minnetonka, Mounds Bay Park. Public access is listed as yes.

Where this data comes from

182 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA182 samples · 2020–2024

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

Named boat-access points from the USGS National Boat Ramps inventory

Ice data from Minnesota DNR Climate