Kinmundy Old Lake is a highly nutrient-loaded hypereutrophic lake in Marion County, Illinois. Water quality is graded F based on 2 sampling years through 2022. Limited fish-species data available. Public access is available. Compared to the 5 other monitored lakes in Marion County, Kinmundy Old Lake ranks #6 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois DNR, last sampled 2022-10-05. Grade methodology: LakeGrade methodology.
Watch Kinmundy Old Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 1.5 ft of visibility. Phosphorus level: 212.5 µg/L. Trophic State Index: 76.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.5 ft | F |
| Phosphorus | 212.5 µg/L | F |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 76 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Kinmundy Old Lake
Compare lakeside cabins, hotels, and vacation rentals near Kinmundy Old Lake in Marion 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.
Top-rated places to stay near Kinmundy Old 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 trip to Kinmundy Old Lake?
Get lake water-quality report cards plus the best cabin & lodging deals near Kinmundy Old Lake — straight to your inbox. No spam, unsubscribe anytime.
Planning a whole trip? See where to stay at Illinois’s top lakes →
Fishing Kinmundy Old Lake
Water Temperature
Kinmundy Old Lake averages about 74°F at the surface in summer, usually warmest in Aug (about 76°F) and coldest in Apr (about 57°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 160 field readings (2011–2022) via the EPA Water Quality Portal. See the full Kinmundy Old Lake water temperature breakdown →
Location
County Ranking
Ranked #6 of 6 lakes in Marion County
Cleaner Lakes Within 30 Miles
Kinmundy Old Lake holds Grade F. 3 nearby lakes hold higher grades.
- DKinmundy New LakeMarion County · 0.5 mi · Higher grade (F → D)
- DForbes LakeMarion County · 6.2 mi · Higher grade (F → D)
- DCentralia LakeMarion County · 16.1 mi · Higher grade (F → D)
Nearby Lakes in Marion County
Explore Kinmundy Old Lake across LakeGrade
Species activity outlook by water temperature and season
Where to stay at Illinois's top lakes, each with its grade
Very high nutrients, dense algae, poor clarity
Illinois's cleanest and most-polluted lakes, ranked
More Illinois Lake Rankings
Other Grade F Lakes in Illinois
Hypereutrophic Lakes in Illinois
More records, surveys & data sources
Reservoir Info (USACE NID)
Kinmundy Old Lake is a man-made reservoir impounded by the Kinmundy Lake Dam (completed 1885), built primarily for recreation on the TRIB EAST FORK KASKASKIA RIVER; earth-type dam, 25 ft tall and 1,050 ft long.
- Normal storage
- 87 ac-ft
- Max storage
- 121 ac-ft
- Hazard class
- Low
- Owner
- CITY OF KINMUNDY
Source: USACE National Inventory of Dams, NID ID IL00248 · Operator website · Matched by proximity (0.19 km)
EPA Impairment Status
Kinmundy Old Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IL_ROZY · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Kinmundy Old Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Alma Stp, Village OfAlma · 2.8 mi away · NPDES IL0076422Recent 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.
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Grading methodology based on Metropolitan Council standards
Most recent sample: 2022-10-05
Monitoring stations: 2