Lakes / Illinois / Washington County / Washington County Lake
Washington County Lake, Illinois
287.14 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Illinois
38.28 degrees N, 89.35 degrees W - Washington County. State and county outlines drawn from Census boundary data; the lake marker is placed by its USGS National Hydrography Dataset coordinates, not by eye. Schematic - not a survey map.
How Washington County Lake Stacks Up
- Larger than 82% of the 511 lakes counted in Illinois.
- The largest lake in Washington County among those counted.
- About 39 miles from Carbondale, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Nashville City Reservoir | Washington | 4.7 mi | 43.98 acres |
| Pinckneyville Reservoir | Perry | 13 mi | 186.56 acres |
| Big Forked Lake | Clinton | 15 mi | 26.69 acres |
| City Reservoir | Randolph | 16 mi | 33.36 acres |
| Du Quoin Lake | Perry | 16 mi | 244.39 acres |
| Long Lake | Clinton | 16 mi | 25.45 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Washington County Lake
How Big Is Washington County Lake?
Washington County Lake covers 287.14 acres in Washington County, Illinois.
What Is the Largest Lake in Washington County?
Washington County Lake is the largest lake in Washington County, at 287.14 acres.
Largest Lakes in Illinois
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Carlyle Lake | Clinton | 22,796.77 acres | - |
| 2 | Mine Number 21 Reservoir | Franklin | 17,062.04 acres | - |
| 3 | Upper Peoria Lake | Woodford | 15,460.64 acres | - |
| 4 | Lake Shelbyville | Shelby | 10,235.1 acres | - |
| 5 | Crab Orchard Lake | Williamson | 7,292.57 acres | - |
All 511 Illinois lakes ranked by surface area
Sources: USGS National Hydrography Dataset (The National Map) lake data (ID 48771176). Verified October 30, 2026.