Kinmundy New Lake
Marion County, Illinois100 acresView mapDirections
Nutrients and algae run well above the regional average.
↓ down from D at the last regrade
- Hypereutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- #6 of 6 in the county
- 38 ft max depth
- Public access
- Limited data
Kinmundy New Lake in Marion County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 2.9 ft visibility. Phosphorus: 49.5 µg/L. Chlorophyll-a (algae): 38 µg/L. Surface area: 100 acres.
- Clarity
- 2.9 ft
- Typical in August
- 79°F
- Max depth
- ~38 ft est.
- Area
- 100 acres
- Type
- Hypereutrophic
- Phosphorus
- 49.5 µg/L
- Chlorophyll-a
- 38 µg/L
- Public access
- Yes
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Compare lakeside cabins, hotels, and vacation rentals near Kinmundy New 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Kinmundy New Lake are listed below.
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Kinmundy New Lake is a 100-acre highly nutrient-loaded hypereutrophic lake in Marion County, Illinois with an estimated average depth of about 38 feet. 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 New Lake ranks #6 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-10-12. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyLimited 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.
The F is nutrients and algae, not a swimming clearance. Kinmundy New Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 2.9 ft of visibility. Phosphorus 49.5 µg/L. Chlorophyll-a 38 µg/L. TSI 63. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.9 ft | Not graded |
| Phosphorus | 49.5 µg/L | Fair |
| Chlorophyll-a (Algae) | 38 µg/L | Poor |
| Trophic State Index (TSI) | 63 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Kinmundy New Lake typically sits around 79°F at the surface in August. Summer average is about 77°F. Usually warmest in Aug (about 79°F) and coldest in Apr (about 60°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 410 field readings (2010–2022) via the EPA Water Quality Portal. See the full Kinmundy New Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~38 ft est. |
| Average Depth | ~7 ft est. |
| Surface Area | 100 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Illinois has not published bathymetry for Kinmundy New Lake.
Lake Size & Watershed
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 Kinmundy New Lake
Reservoir Info (USACE NID)
Kinmundy New Lake is a man-made reservoir impounded by the Kinmundy New Lake Dam (completed 1998), built primarily for recreation on the TRIB EAST FORK KASKASKIA RIVER; earth-type dam, 38 ft tall and 1,250 ft long.
- Surface area
- 100 ac
- Normal storage
- 1,192 ac-ft
- Max storage
- 2,250 ac-ft
- Drainage area
- 1.91 sq mi
- Hazard class
- High
- Owner
- CITY OF KINMUNDY
All listed purposes: Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID IL50271 · Operator website
EPA Impairment Status
Kinmundy New 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_SOF · Official waterbody report
County Ranking
Ranked #6 of 6 lakes in Marion County
Nearby Lakes in Marion County
Frequently asked questions about Kinmundy New Lake
Where is Kinmundy New Lake?
- Kinmundy New Lake is a lake in Marion County, Illinois. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Kinmundy New Lake?
- Kinmundy New Lake in Marion County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 2.9 ft visibility. Phosphorus: 49.5 µg/L. Chlorophyll-a (algae): 38 µg/L. Surface area: 100 acres.
Is Kinmundy New Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Kinmundy New Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Kinmundy New Lake?
- Kinmundy New Lake typically sits around 79°F at the surface in August, from 410 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.
How deep is Kinmundy New Lake?
- No published bathymetric survey covers Kinmundy New Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 38 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 100 acres.
Explore Kinmundy New Lake across LakeQuality
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
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Where this data comes from
42 measurements from 3 monitoring stations, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- illinois epa
IL_EPA_WQX42 samples · 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
Lake size & watershed from HydroLAKES (HydroSHEDS)