Two canoes crossing open water between forested points in the Boundary Waters

Updated August 2026

Biggest Lake in Massachusetts: Quabbin Reservoir (25,216 acres)

Quabbin Reservoir is Massachusetts's largest lake per the U.S. Army Corps of Engineers, National Inventory of Dams (Quabbin Winsor Dam, MA00588); reservoir managed by MA DCR Division of Water Supply Protection. Below: 50 Massachusetts lakes ranked by surface area.

The largest lake in Massachusetts is Quabbin Reservoir at 25,216 acres , in Hampshire, Worcester, Franklin County, according to the U.S. Army Corps of Engineers, National Inventory of Dams (Quabbin Winsor Dam, MA00588); reservoir managed by MA DCR Division of Water Supply Protection.

See our Quabbin Reservoir water-quality report card NR

Source: U.S. Army Corps of Engineers, National Inventory of Dams (Quabbin Winsor Dam, MA00588); reservoir managed by MA DCR Division of Water Supply Protection (2026-07-30). The table below ranks the Massachusetts lakes in our own index by surface area.

Lakes with area data

24,043

Largest (acres)

500

Median of top 50

9/50

Reservoirs (vs natural)

Reading Massachusetts's size profile

Massachusetts's largest lake by surface area is Quabbin Reservoir in Worcester County, spanning 24,043 acres. Most of Massachusetts's biggest waters are natural basins left by glaciers, with stable shorelines and deep main basins.

Surface area is a poor proxy for water quality on its own — a large lake can hold a clean, deep core and a nutrient-loaded bay at the same time. Each lake below links to its full report card with grade, clarity, depth, and EPA impairment status. Area figures come from state DNR surveys and the USACE National Inventory of Dams; grades come from EPA and state monitoring data.

The 50 biggest lakes in Massachusetts by surface area

#	Lake	County	Surface area	Max depth	Grade
1	Quabbin Reservoir	Worcester	24,043 acres	-	NR
2	Wachusett Reservoir	Worcester	4,160 acres	-	NR
3	Assawompset Pond	Plymouth	2,048 acres	-	NR
4	Long Pond	Plymouth	1,782 acres	-	NR
5	Watuppa Pond	Bristol	1,758 acres	-	NR
6	Webster Lake	Worcester	1,442 acres	-	NR
7	Sudbury Reservoir	Worcester	1,300 acres	-	A
8	Great Quittacas Pond	Plymouth	1,145 acres	-	NR
9	Cobble Mountain Reservoir	Hampden	1,066 acres	-	NR
10	Otis Reservoir	Berkshire	989 acres	-	NR
11	Edgartown Great Pond	Dukes	876 acres	-	NR
12	Long Pond	Barnstable	730 acres	-	NR
13	Tisbury Great Pond	Dukes	706 acres	-	NR
14	Onota Lake	Berkshire	646 acres	-	NR
15	Snipatuit Pond	Plymouth	644 acres	-	NR
16	Squibnocket Pond	Dukes	607 acres	-	NR
17	Silver Lake	Plymouth	602 acres	-	NR
18	Copicut Reservoir	Bristol	594 acres	-	NR
19	Lake Cochichewick	Essex	575 acres	-	NR
20	Pottapaug Pond	Worcester	574 acres	-	NR
21	Wequaquet Lake	Barnstable	573 acres	-	NR
22	Menemsha Pond	Dukes	570 acres	-	NR
23	Whitehall Reservoir	Middlesex	561 acres	-	NR
24	Cambridge Reservoir	Middlesex	546 acres	-	C
25	Quaboag Pond	Worcester	544 acres	-	NR
26	Pontoosuc Lake	Berkshire	500 acres	-	NR
27	Great Herring Pond	Plymouth	415 acres	-	NR
28	Hamilton Reservoir	Hampden	400 acres	-	A
29	Springfield Reservoir	Hampden	393 acres	-	NR
30	Massapoag Lake	Norfolk	389 acres	-	NR
31	Stockbridge Bowl	Berkshire	384 acres	-	NR
32	Lake Nippenicket	Plymouth	375 acres	-	NR
33	Lake Attitash	Essex	369 acres	-	NR
34	Manchaug Pond	Worcester	365 acres	-	NR
35	East Brimfield Reservoir	Worcester	360 acres	-	C
36	Tighe Carmody Reservoir	Hampshire	356 acres	-	NR
37	Wakeby Pond	Barnstable	353 acres	-	NR
38	Singletary Pond	Worcester	342 acres	-	NR
39	Pine Hill Reservoir	Worcester	336 acres	-	NR
40	Big Pond	Berkshire	325 acres	-	NR
41	Bare Hill Pond	Worcester	324 acres	-	A
42	Neponset Reservoir	Norfolk	323 acres	-	NR
43	White Island Pond	Plymouth	322 acres	-	NR
44	Johns Pond	Barnstable	317 acres	-	NR
45	Wickaboag Pond	Worcester	315 acres	-	NR
46	Upper Naukeag Lake	Worcester	311 acres	-	NR
47	Hickory Hills Lake	Worcester	310 acres	-	NR
48	Putnamville Reservoir	Essex	310 acres	-	NR
49	Stiles Reservoir	Worcester	309 acres	-	NR
50	Weymouth Great Pond	Norfolk	309 acres	-	NR

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Frequently Asked Questions

What is the largest lake in Massachusetts?

Quabbin Reservoir, at 25,216 acres, in Hampshire, Worcester, Franklin County. Source: U.S. Army Corps of Engineers, National Inventory of Dams (Quabbin Winsor Dam, MA00588); reservoir managed by MA DCR Division of Water Supply Protection, 2026-07-30.

How is lake surface area measured?

Surface area comes from state DNR lake surveys and, for reservoirs, US Army Corps of Engineers (USACE) National Inventory of Dams records. Area is reported in acres at normal pool level. Reservoirs rise and fall with management and drought, so their listed area is the long-term normal rather than a single-day reading.

Are Massachusetts's largest lakes natural or reservoirs?

Of the top 50 Massachusetts lakes by area, 9 sit on a dammed river (reservoirs) and 41 are natural basins. Glacial states (MN, WI, MI, NY) skew natural; plains and southern states (MO, IA, ND, OH) skew toward reservoirs built for water supply, flood control, and recreation.

Do larger lakes have better water quality?

Not reliably. Quality varies more within a big lake than between lakes — a large lake can have a clean, deep main basin and a murky, algae-prone bay fed by a tributary, so one grade can mask wide swings. Depth, watershed land use, and how fast the lake flushes matter far more than raw surface area.

How big is the typical Massachusetts lake in this ranking?

Across the top 50 Massachusetts lakes by surface area, the median is 500 acres (Pontoosuc Lake). This list is biased toward the biggest waters; the typical Massachusetts lake is far smaller.

Where to stay near Massachusetts's largest lakes

Planning a trip? Jump to live cabin, resort, and hotel availability near Massachusetts's biggest lakes.

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