Nitrogen Sensitive Areas
The designated watersheds
Watershed boundaries follow groundwater, not roads. They cross town lines freely — and the towns either side did not always file the same way.
| Watershed | Towns | Strongest filing |
|---|---|---|
| Pleasant Bay | Brewster, Chatham, Harwich, Orleans | Permit granted |
| Bass River | Brewster, Dennis, Yarmouth | De Minimis application |
| Herring River | Brewster, Dennis, Harwich | Permit application |
| Popponesset Bay | Barnstable, Mashpee, Sandwich | Permit application |
| Three Bays | Barnstable, Mashpee, Sandwich | Permit application |
| Wellfleet Harbor | Eastham, Truro, Wellfleet | Notice of Intent |
| Bournes Pond | Falmouth, Mashpee | De Minimis application |
| Green Pond | Falmouth, Mashpee | De Minimis application |
| Lewis Bay | Barnstable, Yarmouth | Permit application |
| Swan Pond River | Brewster, Dennis | De Minimis application |
| Waquoit Bay | Mashpee, Sandwich | Notice of Intent |
| Allen Harbor | Harwich | Notice of Intent |
| Barnstable Harbor | Barnstable | Permit application |
| Centerville River | Barnstable | Permit application |
| Eel Pond / Waquoit Bay | Falmouth | Notice of Intent |
| Falmouth Inner Harbor | Falmouth | Notice of Intent |
| Fiddlers Cove | Falmouth | Notice of Intent |
| Great Pond | Falmouth | Notice of Intent |
| Halls Creek | Barnstable | Permit application |
| Little Pond | Falmouth | Notice of Intent |
| Megansett Harbor | Falmouth | Notice of Intent |
| Megansett–Squeteague Harbor | Bourne | Notice of Intent |
| Oyster Pond | Falmouth | Notice of Intent |
| Parkers River | Yarmouth | Notice of Intent |
| Phinney's Harbor | Bourne | Notice of Intent |
| Quissett Harbor | Falmouth | Notice of Intent |
| Rands Canal | Falmouth | Notice of Intent |
| Rushy Marsh | Barnstable | Permit application |
| Saquatucket Harbor | Harwich | Notice of Intent |
| Stage Harbor | Chatham | Notice of Intent |
| Sulfur Springs / Bucks Creek | Chatham | Notice of Intent |
| Taylors Pond / Mill Creek | Chatham | Notice of Intent |
| West Falmouth Harbor | Falmouth | Notice of Intent |
| Wild Harbor | Falmouth | Notice of Intent |
| Wychmere Harbor | Harwich | Notice of Intent |
A note on names and counting. MassDEP states that 31 watersheds are designated.
The application table spells some of them more than one way — "3 Bays" and "Three Bays",
"Swan Pond" and "Swan Pond River" — so this list normalises names and records the original
spelling. Where our count differs from 31, the source spelling is the reason.
MassDEP watershed application table, 11 June 2026.