Lakes / Iowa / Jefferson County / Reservoir Number One
Reservoir Number One, Iowa
25 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Iowa
41.02 degrees N, 91.95 degrees W - Jefferson 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 Reservoir Number One Stacks Up
- Larger than 0% of the 220 lakes counted in Iowa.
- About 68 miles from Cedar Rapids, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Reservoir Number Two | Jefferson | 0.6 mi | 48 acres |
| Walton Lake | Jefferson | 1.2 mi | 42 acres |
| Horse Shoe Lake | Jefferson | 12 mi | 32 acres |
| Lake Darling | Washington | 12 mi | 243 acres |
| Indian Lake | Van Buren | 29 mi | 49 acres |
| Lake Fisher | Davis | 31 mi | 73 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Reservoir Number One
How Big Is Reservoir Number One?
Reservoir Number One covers 25 acres in Jefferson County, Iowa.
What Is the Largest Lake in Jefferson County?
Reservoir Number Two is the largest lake in Jefferson County, at 48 acres.
Largest Lakes in Iowa
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Rathbun Lake | Appanoose | 13,869 acres | - |
| 2 | Lake Red Rock | Marion | 8,619 acres | - |
| 3 | Spirit Lake | Dickinson | 5,463 acres | - |
| 4 | Saylorville Lake | Polk | 5,428 acres | - |
| 5 | Clear Lake | Cerro Gordo | 3,632 acres | - |
All 220 Iowa lakes ranked by surface area
Sources: USGS NHD (The National Map NHD MapServer layer 12) named waterbodies FTYPE 390/436; counties via Census point-in-polygon lake data (ID 152819470). Verified October 30, 2026.