Lakes / Illinois / Washington County
Lakes in Washington County, Illinois
3 lakes counted in Washington County - the largest is Washington County Lake at 287.14 acres.
3
Lakes Counted
287.14 acres
Largest - Washington County Lake
Washington County, highlighted, with its largest counted lakes dotted. Outlines from Census boundary data.
All Counted Lakes
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Washington County Lake | Washington | 287.14 acres | - |
| 2 | Nashville City Reservoir | Washington | 43.98 acres | - |
| 3 | Calamus Lake | Washington | 31.88 acres | - |
Sources: USGS National Hydrography Dataset lake data; USGS. Verified October 30, 2026.