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LakeQuality

Charleston Side Channel Lake

Coles County, IllinoisView mapDirections

F
Algae-prone

Nutrients and algae run well above the regional average.

↓ down from D at the last regrade

Water temp
~83°F
Typical for Aug · EPA WQP
Clarity
No reading
No sample
Level
No reading
No gauge
Trend
No reading
Not enough history
  • Hypereutrophic
  • Impaired · Nutrients (phosphorus, nitrogen)
  • #2 of 2 in the county
  • 27 ft max depth
  • Public access
  • Limited data

Charleston Side Channel Lake in Coles County, Illinois has a water quality grade of F (Algae-prone). Phosphorus: 121 µg/L. Chlorophyll-a (algae): 56.1 µg/L.

Typical in August
83°F
Max depth
~27 ft est.
Type
Hypereutrophic
Public access
Yes
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Stays near Charleston Side Channel Lake

Compare lakeside cabins, hotels, and vacation rentals near Charleston Side Channel Lake in Coles 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 Charleston Side Channel Lake are listed below.

Top-rated places to stay near Charleston Side Channel Lake

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Charleston Side Channel Lake is a highly nutrient-loaded hypereutrophic lake in Coles County, Illinois with an estimated average depth of about 27 feet. Water quality is graded F based on 2 sampling years through 2021. Limited fish-species data available. Public access is available with 2 public boat landings. Compared to the 1 other monitored lakes in Coles County, Charleston Side Channel Lake ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2021-10-13. Grade methodology: LakeQuality methodology.

What Charleston Side Channel Lake is good for

From access and monitoring records, not editorial picks.

  • Boat launch2 documented ramps

Swimming Safety

Grade only

Limited 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. Charleston Side Channel Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.

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Get alerts for Charleston Side Channel Lake

Water Quality Grade: F (Algae-prone)

No clarity data. Phosphorus 121 µg/L. Chlorophyll-a 56.1 µg/L. TSI 72. The letter is not a swimming clearance.

MetricValueGrade
Water Clarity (Secchi Depth)No recent samples
Phosphorus121 µg/LPoor
Chlorophyll-a (Algae)56.1 µg/LPoor
Trophic State Index (TSI)72Hypereutrophic

Very high nutrients, dense algae, poor clarity

Water Temperature

Charleston Side Channel Lake typically sits around 83°F at the surface in August. Summer average is about 81°F. Usually warmest in Jul (about 85°F) and coldest in Apr (about 61°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
61°
May
Jun
74°
Jul
85°
Aug
83°
Sep
Oct
67°
Nov
Dec

Typical surface water temperature by month, from 156 field readings (20112021) via the EPA Water Quality Portal. See the full Charleston Side Channel Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth~27 ft est.
Average Depth~23 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 Charleston Side Channel Lake.

Lake Size & Watershed

Watershed (drainage) area
783 sq mi
Surface area
405 acres
Shoreline
4.1 mi
Elevation
584 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
  • Charleston Side ChannelPublic
  • Lake Charleston Spillway ParkPublic

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

Fishing Charleston Side Channel Lake

Reservoir Info (USACE NID)

Charleston Side Channel Lake is a man-made reservoir impounded by the Lake Charleston Dam (completed 1981), built primarily for water supply on the TRIB EMBARASS RIVER; earth-type dam, 29 ft tall and 4,400 ft long.

Normal storage
2,360 ac-ft
Max storage
3,775 ac-ft
Hazard class
Significant
Owner
CITY OF CHARLESTON

Source: USACE National Inventory of Dams, NID ID IL01240 · Operator website · Matched by proximity (0.33 km)

EPA Impairment Status

Charleston Side Channel Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Nutrients (phosphorus, nitrogen)

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

Source: EPA ATTAINS assessment unit IL_RBC · Official waterbody report · Matched by proximity (0.25 km)

Regulated Pollution Sources Nearby

2 EPA-permitted facilities operate within about 5 miles of Charleston Side Channel 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.

  • Charleston Stp, City Of
    Charleston · 3.8 mi away · NPDES IL0021644
    MajorRecent violation
  • Illinois Department Of Natural Resources - Fox Ridge State Park Stp
    Charleston · 4.5 mi away · NPDES IL0051250

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 2 lakes in Coles County

Nearby Lakes in Coles County

Frequently asked questions about Charleston Side Channel Lake

Where is Charleston Side Channel Lake?

Charleston Side Channel Lake is a lake in Coles County, Illinois. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Charleston Side Channel Lake?

Charleston Side Channel Lake in Coles County, Illinois has a water quality grade of F (Algae-prone). Phosphorus: 121 µg/L. Chlorophyll-a (algae): 56.1 µg/L.

Is Charleston Side Channel Lake safe to swim in?

The F is nutrients and algae, not a swimming clearance. Charleston Side Channel Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.

What is the water temperature of Charleston Side Channel Lake?

Charleston Side Channel Lake typically sits around 83°F at the surface in August, from 156 EPA Water Quality Portal field readings (2011–2021). That is a typical value for the month, not a live reading.

How deep is Charleston Side Channel Lake?

No published bathymetric survey covers Charleston Side Channel Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 27 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 Charleston Side Channel Lake?

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

Hypereutrophic Lakes in Illinois

Where this data comes from

55 measurements from 3 monitoring stations, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • illinois epaIL_EPA_WQX55 samples · 2021

Analytical methods

  • 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