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LakeQuality

Yankton Lake

D
Grade D — Nutrient-rich
Nutrient-rich · #1 of 2 lakes in the county · 0.8 ft clear · Hypereutrophic · 403 acres · from F
Limited DataHypereutrophic

Yankton Lake in Lyon County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 0.8 ft visibility. Phosphorus: 98 µg/L. Chlorophyll-a (algae): 20.3 µg/L. Maximum depth: 8 ft. Surface area: 402.57 acres.

Clarity
0.8 ft
Typical in August
72°F
Max depth
8 ft
Area
403 acres
Type
Hypereutrophic
Public access
Yes
Ice-out
Apr 12

Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Yankton Lake

Next lake in Lyon County

FCottonwood Lake1.8 ft clear · Lyon CountyView →
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Yankton Lake is a 403-acre highly nutrient-loaded hypereutrophic lake in Lyon County, Minnesota with a maximum depth of 8 feet. Water quality is graded D based on 2 sampling years through 2025. The lake supports 15 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available with 1 public boat landing. Compared to the 1 other monitored lakes in Lyon County, Yankton Lake ranks #1 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-16. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Limited 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.

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum

Compare the safest swimming lakes near Sioux Falls

Get alerts for Yankton Lake

Water Quality Grade: D (Nutrient-rich)

Very murky, less than 0.8 ft of visibility. Phosphorus level: 98 µg/L. Chlorophyll-a: 20.3 µg/L. Trophic State Index: 70.

MetricValueGrade
Water Clarity (Secchi Depth)0.8 ftNot graded
Phosphorus98 µg/LPoor
Chlorophyll-a (Algae)20.3 µg/LPoor
Trophic State Index (TSI)70Hypereutrophic

Very high nutrients, dense algae, poor clarity

Where to stay near Yankton Lake

Compare lakeside cabins, hotels, and vacation rentals near Yankton Lake in Lyon 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 Yankton Lake are listed below.

Top-rated places to stay near Yankton 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

Yankton Lake typically sits around 72°F at the surface in August. Summer average is about 78°F. Usually warmest in Jul (about 83°F) and coldest in Aug (about 72°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
Jun
Jul
83°
Aug
72°
Sep
72°
Oct
Nov
Dec

Typical surface water temperature by month, from 9 field readings (20252025) via the EPA Water Quality Portal. See the full Yankton Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth8 ft
Surface Area403 acres
Shoreline Length4.9 mi
Littoral Zone100%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
2 sq mi
Elevation
1,506 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Yankton LakePublic

Fish Species

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

Fishing Yankton Lake

Ice Season

Historical ice data from Minnesota DNR (4 observations).

Typical Ice-Out
Apr 12
EarliestLatest
Ice-Out2017-03-05 (2017)2008-04-11 (2008)
Ice-In2008-11-28 (2008)2008-11-28 (2008)

Most recent ice-out: 2017-03-05

Reservoir Info (USACE NID)

Yankton Lake is a man-made reservoir impounded by the Lake Yankton (completed 1942), built primarily for flood risk reduction on the Dog Creek-TR; gravity-type dam, 8 ft tall and 17 ft long.

Surface area
380 ac
Normal storage
380 ac-ft
Max storage
380 ac-ft
Drainage area
4.6 sq mi
Hazard class
Low
Owner
City of Balaton

Source: USACE National Inventory of Dams, NID ID MN00230 · Operator website

EPA Impairment Status

Yankton Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Impaired biota (cause unknown)Nutrients (phosphorus, nitrogen)

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

Source: EPA ATTAINS assessment unit MN42-0047-00 · Official waterbody report

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Yankton Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.

  • Balaton Wwtp
    Balaton · 1 mi away · NPDES MN0020559
    Recent violation

Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.

County Ranking

Ranked #1 of 2 lakes in Lyon County

Nearby Lakes in Lyon County

Frequently asked questions about Yankton Lake

What is the water quality grade for Yankton Lake?

Yankton Lake in Lyon County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 0.8 ft visibility. Phosphorus: 98 µg/L. Chlorophyll-a (algae): 20.3 µg/L. Maximum depth: 8 ft. Surface area: 402.57 acres.

Is Yankton Lake safe to swim in?

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Yankton Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 20.3 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Yankton Lake?

Yankton Lake typically sits around 72°F at the surface in August, from 9 EPA Water Quality Portal field readings (2025–2025). That is a typical value for the month, not a live reading.

How deep is Yankton Lake?

Yankton Lake has a maximum depth of 8 feet. The lake covers 402.57 acres.

What fish are in Yankton Lake?

Fish species found in Yankton Lake include bigmouth buffalo, black bullhead, black crappie, bluegill, common carp, green sunfish, hybrid sunfish, northern pike, orangespotted sunfish, pumpkinseed, walleye, white crappie, white sucker, yellow bullhead, yellow perch. Yankton Lake is located in Lyon County, Minnesota.

When does Yankton Lake thaw?

Yankton Lake typically has ice-out around Apr 12.

Are there boat ramps on Yankton Lake?

Yankton Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Yankton Lake. Public access is listed as yes.

Hypereutrophic Lakes in Minnesota

Where this data comes from

9 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 WaterMNPCA9 samples · 2025

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by 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

Regulated discharger data from EPA ECHO (ICIS-NPDES)

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