Hydrological Unit: Housatonic
| HUC | Name |
|---|---|
| 0110000501 | Headwaters Housatonic River |
| 0110000502 | Williams River-Housatonic River |
| 0110000503 | Konkapot River-Housatonic River |
| 0110000504 | Macedonia Brook-Housatonic River |
| 0110000505 | Tenmile River |
| 0110000506 | Lake Candlewood-Housatonic River |
| 0110000507 | Shepaug River |
| 0110000508 | Still River-Housatonic River |
| 0110000509 | Pomperaug River |
| 0110000510 | Eightmile Brook-Housatonic River |
| 0110000511 | Headwaters Naugatuck River |
| 0110000512 | Outlet Naugatuck River |
| 0110000513 | Housatonic River-Frontal Long Island Sound |