Lakes / Illinois / Putnam County / Senachwine Lake
Senachwine Lake, Illinois
5,449.75 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Illinois
41.19 degrees N, 89.36 degrees W - Putnam 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 Senachwine Lake Stacks Up
- Ranks #6 for surface area among the Illinois lakes counted so far - 5,449.75 acres.
- The largest lake in Putnam County among those counted.
- About 36 miles from Peoria, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Swan Lake | Putnam | 2.9 mi | 167.31 acres |
| Lake Thunderbird | Putnam | 4.8 mi | 107.24 acres |
| Sawmill Lake | Putnam | 5.0 mi | 556.48 acres |
| Hickory Ridge Lake | Bureau | 5.4 mi | 62.02 acres |
| Coleman Lake | Putnam | 7.1 mi | 148.55 acres |
| Lake Rawson | Bureau | 7.4 mi | 134.43 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Senachwine Lake
How Big Is Senachwine Lake?
Senachwine Lake covers 5,449.75 acres in Putnam County, Illinois.
What Is the Largest Lake in Putnam County?
Senachwine Lake is the largest lake in Putnam County, at 5,449.75 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 152225331). Verified October 30, 2026.