Rooster River is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in Fairfield County

Fairfield County, Connecticut

Fairfield County is a county located in the southwestern corner of the U.S. state of Connecticut. The county population is 916,829 according to the 2010 Census. There are currently 1,465 people per square mile in the county. It is the most populous county in the State of Connecticut and contains...

, Connecticut

Connecticut

Connecticut is a state in the New England region of the northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, and the state of New York to the west and the south .Connecticut is named for the Connecticut River, the major U.S. river that approximately...

 that lies on and serves as the border between Bridgeport

Bridgeport, Connecticut

Bridgeport is the most populous city in the U.S. state of Connecticut. Located in Fairfield County, the city had an estimated population of 144,229 at the 2010 United States Census and is the core of the Greater Bridgeport area...

 and Fairfield

Fairfield, Connecticut

Fairfield is a town located in Fairfield County, Connecticut, United States. It is bordered by the towns of Bridgeport, Trumbull, Easton, Redding and Westport along the Gold Coast of Connecticut. As of the 2010 census, the town had a population of 59,404...

. It has flooded on numerous occasions and so has its own flood control project.
Rooster River extends southward into Long Island Sound

Long Island Sound

Long Island Sound is an estuary of the Atlantic Ocean, located in the United States between Connecticut to the north and Long Island, New York to the south. The mouth of the Connecticut River at Old Saybrook, Connecticut, empties into the sound. On its western end the sound is bounded by the Bronx...

 as Ash Creek

Ash Creek (Connecticut)

Ash Creek is a tidal creek and intertidal wetland in Fairfield County, Connecticut that serves as a border between the city of Bridgeport and the town of Fairfield. It is the last salt water estuary in the area, extending from Long Island Sound and up the Rooster River.-History:The area was known...

. The source of the river is Lake Forest in Bridgeport, Horse Tavern Brook in Trumbull, and London's Brook from the Fairchild Wheeler golf course.