The river continues through Ridgefield, and is augmented by the "Great Pond" (507 feet (155 m) above sea level), one of the purest lakes in Connecticut due to its being fed by underwater springs.

The river is closely paralleled by U.S. Route 7 as it flows southward through Branchville, Georgetown, Wilton, and Norwalk, where it is joined by the Silvermine River and then flows into Norwalk Harbor and finally into Long Island Sound.

A 20-year-old man drowned in the river on May 24, 2009 while trying to save a boy who slipped into a strong current near Broad Street in northern Norwalk, near the Route 7 Connector.

(The statewide destruction prompted President Eisenhower to declare a disaster area in Connecticut.)

Several people died in addition to millions of dollars worth of damage along the Norwalk River watershed alone.