Centralia Lake
Marion County, Illinois300 acresView mapDirections
Nutrients and algae run well above the regional average.
↓ down from D at the last regrade
- Hypereutrophic
- Impaired · Mercury
- #3 of 6 in the county
- 39 ft max depth
- Public access
- Limited data
Centralia Lake in Marion County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 1.5 ft visibility. Phosphorus: 132 µg/L. Chlorophyll-a (algae): 69.7 µg/L. Surface area: 300 acres.
- Clarity
- 1.5 ft
- Typical in September
- 73°F
- Max depth
- ~39 ft est.
- Area
- 300 acres
- Type
- Hypereutrophic
- Phosphorus
- 132 µg/L
- Chlorophyll-a
- 69.7 µg/L
- Public access
- Yes
Stays via Stay22
Stays near Centralia Lake
Compare lakeside cabins, hotels, and vacation rentals near Centralia 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 Centralia Lake are listed below.
Top-rated places to stay near Centralia Lake
Prices for Sep 11–13, 4 adults. Change dates on the map below.
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? Cabins and lodging at Centralia Lake → · more Illinois lake trips
Watch Centralia Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Centralia Lake is a 300-acre highly nutrient-loaded hypereutrophic lake in Marion County, Illinois with an estimated average depth of about 39 feet. Water quality is graded F based on 2 sampling years through 2021. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 5 other monitored lakes in Marion County, Centralia Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2021-10-27. Grade methodology: LakeQuality methodology.
What Centralia Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
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. Centralia Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), pCBs. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 1.5 ft of visibility. Phosphorus 132 µg/L. Chlorophyll-a 69.7 µg/L. TSI 73. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.5 ft | Not graded |
| Phosphorus | 132 µg/L | Poor |
| Chlorophyll-a (Algae) | 69.7 µg/L | Poor |
| Trophic State Index (TSI) | 73 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Centralia Lake typically sits around 73°F at the surface in September. Summer average is about 79°F. Usually warmest in Jul (about 82°F) and coldest in Apr (about 63°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 301 field readings (2012–2022) via the EPA Water Quality Portal. See the full Centralia Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~39 ft est. |
| Average Depth | ~10 ft est. |
| Surface Area | 300 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 Centralia 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.
Recreation & Access
- Centralia LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Centralia Lake
Reservoir Info (USACE NID)
Centralia Lake is a man-made reservoir impounded by the Lake Centralia Dam (completed 1911), built primarily for recreation on the MARTIN BRANCH; earth-type dam, 31 ft tall and 720 ft long.
- Surface area
- 300 ac
- Normal storage
- 2,772 ac-ft
- Max storage
- 4,165 ac-ft
- Drainage area
- 6.7 sq mi
- Hazard class
- Significant
- Owner
- CITY OF CENTRALIA
All listed purposes: Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID IL00239 · Operator website
EPA Impairment Status
Centralia 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_ROI · Official waterbody report
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Centralia Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Raccoon School District C-1 StpCentralia · 3.1 mi away · NPDES IL0052981Recent violation
- Fosters Mobile Home Park StpSalem · 3.5 mi away · NPDES IL0053040
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 #3 of 6 lakes in Marion County
Nearby Lakes in Marion County
Frequently asked questions about Centralia Lake
Where is Centralia Lake?
- Centralia 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 Centralia Lake?
- Centralia Lake in Marion County, Illinois has a water quality grade of F (Algae-prone). Water clarity: 1.5 ft visibility. Phosphorus: 132 µg/L. Chlorophyll-a (algae): 69.7 µg/L. Surface area: 300 acres.
Is Centralia Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Centralia Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), pCBs. Check local advisories before you swim.
What is the water temperature of Centralia Lake?
- Centralia Lake typically sits around 73°F at the surface in September, from 301 EPA Water Quality Portal field readings (2012–2022). That is a typical value for the month, not a live reading.
How deep is Centralia Lake?
- No published bathymetric survey covers Centralia Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 39 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 300 acres.
Are there boat ramps on Centralia Lake?
- Centralia Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Centralia Lake. Public access is listed as yes.
Explore Centralia Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
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
Where this data comes from
51 measurements from 3 monitoring stations, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- illinois epa
IL_EPA_WQX51 samples · 2021
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