Vernor Lake
Richland County, Illinois45 acresView mapDirections
Nutrients and algae run above the regional average.
- Eutrophic
- Impaired · Algal growth
- #2 of 3 in the county
- 26 ft max depth
- Limited data
Vernor Lake in Richland County, Illinois has a water quality grade of D (Nutrient-rich). Water clarity: 4.8 ft visibility. Phosphorus: 114 µg/L. Chlorophyll-a (algae): 29.1 µg/L. Surface area: 45 acres.
- Clarity
- 4.8 ft
- Typical in August
- 73°F
- Max depth
- ~26 ft est.
- Area
- 45 acres
- Type
- Eutrophic
- Phosphorus
- 114 µg/L
- Chlorophyll-a
- 29.1 µg/L
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Stays near Vernor Lake
Compare lakeside cabins, hotels, and vacation rentals near Vernor Lake in Richland 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 Vernor Lake are listed below.
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Watch Vernor Lake’s letter
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Vernor Lake is a 45-acre productive, nutrient-rich eutrophic lake in Richland County, Illinois with an estimated average depth of about 26 feet. Water quality is graded D based on 2 sampling years through 2022. Compared to the 2 other monitored lakes in Richland County, Vernor Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-10-25. 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 D is nutrients and algae, not a swimming clearance. Vernor Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 4.8 ft. Phosphorus 114 µg/L. Chlorophyll-a 29.1 µg/L. TSI 64. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.8 ft | Not graded |
| Phosphorus | 114 µg/L | Poor |
| Chlorophyll-a (Algae) | 29.1 µg/L | Poor |
| Trophic State Index (TSI) | 64 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Temperature
Vernor Lake typically sits around 73°F at the surface in August. Summer average is about 72°F. Usually warmest in Jul (about 75°F) and coldest in Oct (about 59°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 217 field readings (2014–2022) via the EPA Water Quality Portal. See the full Vernor Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~26 ft est. |
| Average Depth | ~6 ft est. |
| Surface Area | 45 acres |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Illinois has not published bathymetry for Vernor 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 Vernor Lake
Reservoir Info (USACE NID)
Vernor Lake is a man-made reservoir impounded by the Vernor Lake Dam (completed 1924), built primarily for recreation on the TRIB FOX RIVER; earth-type dam, 42 ft tall and 820 ft long.
- Surface area
- 45 ac
- Normal storage
- 900 ac-ft
- Max storage
- 972 ac-ft
- Drainage area
- 0.4 sq mi
- Hazard class
- Significant
- Owner
- CITY OF OLNEY
All listed purposes: Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID IL00793 · Operator website
EPA Impairment Status
Vernor Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit IL_RCA · Official waterbody report
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Vernor Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 2 facilities have a reported Clean Water Act violation in the past three years.
- Olney Stp, City OfOlney · 3.2 mi away · NPDES IL0048755MajorRecent violation
- Kincaid Acres Mhp StpOlney · 0.2 mi away · NPDES IL0056146Recent 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 #2 of 3 lakes in Richland County
Nearby Lakes in Richland County
Frequently asked questions about Vernor Lake
Where is Vernor Lake?
- Vernor Lake is a lake in Richland County, Illinois. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Vernor Lake?
- Vernor Lake in Richland County, Illinois has a water quality grade of D (Nutrient-rich). Water clarity: 4.8 ft visibility. Phosphorus: 114 µg/L. Chlorophyll-a (algae): 29.1 µg/L. Surface area: 45 acres.
Is Vernor Lake safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Vernor Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Vernor Lake?
- Vernor Lake typically sits around 73°F at the surface in August, from 217 EPA Water Quality Portal field readings (2014–2022). That is a typical value for the month, not a live reading.
How deep is Vernor Lake?
- No published bathymetric survey covers Vernor Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 26 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 45 acres.
Explore Vernor Lake across LakeQuality
More Illinois Lake Rankings
Other Grade D Lakes in Illinois
Eutrophic Lakes in Illinois
Where this data comes from
41 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_WQX41 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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)