What is base level of Connecticut river?

The base level of the Connecticut River is the Atlantic Ocean. The river flows south from its source in northern New Hampshire, through Massachusetts and Connecticut, and into the Atlantic Ocean at Long Island Sound. The base level of a river is the lowest point to which the river can erode its bed. In the case of the Connecticut River, the base level is the Atlantic Ocean, which is at sea level. The river cannot erode its bed any lower than sea level, so the river's gradient (slope) decreases as it approaches the ocean.