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LakeQuality

Vandalia Lake

Fayette County, IllinoisView mapDirections

F
Algae-prone

Nutrients and algae run well above the regional average.

Water temp
~78°F
Typical for Aug · EPA WQP
Clarity
1.3 ft
Secchi · sampled 2022
Max depth
~55 ft est.
GLOBathy model
Level
No reading
No gauge
Trend
Stable
2 years of samples
  • Hypereutrophic
  • Impaired · Mercury
  • #1 of 1 in the county
  • 55 ft max depth
  • Public access

Vandalia Lake in Fayette County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 1.3 ft visibility. Phosphorus: 103.5 µg/L. Chlorophyll-a (algae): 84.4 µg/L.

Clarity
1.3 ft
Typical in August
78°F
Max depth
~55 ft est.
Type
Hypereutrophic
Phosphorus
103.5 µg/L
Chlorophyll-a
84.4 µg/L
Trend
Stable
Public access
Yes
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Stays near Vandalia Lake

Compare lakeside cabins, hotels, and vacation rentals near Vandalia Lake in Fayette County, Illinois — 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 Vandalia Lake are listed below.

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Vandalia Lake is a highly nutrient-loaded hypereutrophic lake in Fayette County, Illinois with an estimated average depth of about 55 feet. Water quality is graded F based on 2 sampling years through 2022. Phosphorus level is declining over recent sampling years. Limited fish-species data available. Public access is available with 2 public boat landings.

Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-10-27. Grade methodology: LakeQuality methodology.

What Vandalia Lake is good for

From access and monitoring records, not editorial picks.

  • Boat launch2 documented ramps

Swimming Safety

Grade only

Algae 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.

The F is nutrients and algae, not a swimming clearance. Vandalia Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.

Compare the safest swimming lakes near St. Louis

Get alerts for Vandalia Lake

Water Quality Grade: F (Algae-prone)

Very murky, less than 1.3 ft of visibility. Phosphorus 103.5 µg/L. Chlorophyll-a 84.4 µg/L. TSI 73. The letter is not a swimming clearance.

MetricValueGrade
Water Clarity (Secchi Depth)1.3 ftNot graded
Phosphorus103.5 µg/LPoor
Chlorophyll-a (Algae)84.4 µg/LPoor
Trophic State Index (TSI)73Hypereutrophic

Very high nutrients, dense algae, poor clarity

Water Temperature

Vandalia Lake typically sits around 78°F at the surface in August. Summer average is about 76°F. Usually warmest in Aug (about 78°F) and coldest in Nov (about 53°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
64°
Jun
74°
Jul
77°
Aug
78°
Sep
Oct
62°
Nov
53°
Dec

Typical surface water temperature by month, from 218 field readings (20102022) via the EPA Water Quality Portal. See the full Vandalia Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth~55 ft est.
Average Depth~11 ft est.
Public AccessYes

Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Illinois has not published bathymetry for Vandalia Lake.

Lake Size & Watershed

Watershed (drainage) area
25 sq mi
Surface area
608 acres
Shoreline
13.2 mi
Elevation
525 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.

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Vandalia LakePublic
  • Vandalia LakePublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Fishing Vandalia Lake

Based on 2 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Stable0 m/yr2
Phosphorus Declining+28.75 µg/L/yr2
Chlorophyll-a Improving-23.05 µg/L/yr2

EPA Impairment Status

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

Causes of impairment

MercuryNutrients (phosphorus, nitrogen)Turbidity

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

Source: EPA ATTAINS assessment unit IL_ROD · Official waterbody report

Regulated Pollution Sources Nearby

5 EPA-permitted facilities operate within about 5 miles of Vandalia Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.

  • Vandalia Stp
    Vandalia · 3.8 mi away · NPDES IL0023574
    MajorRecent violation
  • Danny George Private Sewage Disposal System
    Vandalia · 0.1 mi away · NPDES IL0080180
  • David Irwin Private Sewage Disposal System
    Vandalia · 0.2 mi away · NPDES IL0080309
  • Leskera Residence Private Sewage Disposal System
    Vandalia · 0.3 mi away · NPDES IL0080294
  • Vandalia Wtp, City Of
    Vandalia · 4.1 mi away · NPDES IL0036897

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 1 lakes in Fayette County

Nearby Lakes in Fayette County

Frequently asked questions about Vandalia Lake

Where is Vandalia Lake?

Vandalia Lake is a lake in Fayette County, Illinois. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Vandalia Lake?

Vandalia Lake in Fayette County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 1.3 ft visibility. Phosphorus: 103.5 µg/L. Chlorophyll-a (algae): 84.4 µg/L.

Is Vandalia Lake safe to swim in?

The F is nutrients and algae, not a swimming clearance. Vandalia Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.

What is the water temperature of Vandalia Lake?

Vandalia Lake typically sits around 78°F at the surface in August, from 218 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.

How deep is Vandalia Lake?

No published bathymetric survey covers Vandalia Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 55 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.

Are there boat ramps on Vandalia Lake?

Vandalia Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Vandalia Lake, Vandalia Lake. Public access is listed as yes.

Where this data comes from

93 measurements from 3 monitoring stations, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • illinois epaIL_EPA_WQX93 samples · 2020–2022

Analytical methods

  • MEASURED IN FIELD
  • Phosphorus by Colorimetry
  • 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (3)

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)

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