Lakes / Massachusetts / Middlesex County / Foss Reservoir (Number Three)
Foss Reservoir (Number Three), Massachusetts
231.07 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Massachusetts
42.30 degrees N, 71.47 degrees W - Middlesex County. State and county outlines drawn from Census boundary data; the lake marker is placed by its Massachusetts Division of Fisheries and Wildlife coordinates, not by eye. Schematic - not a survey map.
How Foss Reservoir (Number Three) Stacks Up
- Larger than 88% of the 784 lakes counted in Massachusetts.
- About 17 miles from Worcester, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Stearns Reservoir (Number 1) | Middlesex | 1.2 mi | 118.17 acres |
| Bracket Reservoir (Number Two) | Middlesex | 2.1 mi | 110.46 acres |
| Farm Pond | Middlesex | 2.5 mi | 151 acres |
| Learned Pond | Middlesex | 2.7 mi | 33.85 acres |
| Sudbury Reservoir | Worcester | 2.7 mi | 1,240 acres |
| Gleason Pond | Middlesex | 3.0 mi | 12 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Foss Reservoir (Number Three)
How Big Is Foss Reservoir (Number Three)?
Foss Reservoir (Number Three) covers 231.07 acres in Middlesex County, Massachusetts.
What Is the Largest Lake in Middlesex County?
Whitehall Reservoir is the largest lake in Middlesex County, at 620 acres.
Deepest Natural Lakes in Massachusetts
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Walden Pond | Middlesex | 62 acres | 100 ft |
| 2 | Cliff Pond | Barnstable | 206 acres | 96 ft |
| 3 | Wallum Lake | Worcester | 322 acres | 81 ft |
| 4 | Onota Lake | Berkshire | 653 acres | 72 ft |
| 5 | Ashumet Pond | Barnstable | 220 acres | 69 ft |
All 211 Massachusetts lakes ranked by depth
Largest Lakes in Massachusetts
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Quabbin Reservoir | Franklin | 24,012 acres | - |
| 2 | Wachusett Reservoir | Worcester | 4,041 acres | - |
| 3 | Assawompset Pond | Plymouth | 2,652.37 acres | - |
| 4 | Watuppa Pond | Bristol | 1,758.37 acres | - |
| 5 | South Watuppa Pond | Bristol | 1,460 acres | 23 ft |
All 784 Massachusetts lakes ranked by surface area
Sources: USGS National Hydrography Dataset (The National Map) lake data (ID 129729009). Verified October 30, 2026.