It flows south-to-north through Punchestown Racecourse, passing Craddockstown Golf Club and Naas Industrial Estate.

It continues northwards and unites with another tributary south of Palmerstown House Golf Club.

The Morell then passes under the Grand Canal via an aqueduct and under the Dublin–Cork railway line, then unites with the Painestown River.

The combined flow passes under the Morell Bridge, where there is an Environmental Protection Agency monitoring station.

There is substantial canopy cover provided by maple sycamore (Acer pseudoplatanus) and European alder (Alnus glutinosa),[3] which allows spawning by the resident population of Brown trout and migratory populations of sea trout (Salmo trutta) and Atlantic salmon (Salmo salar)[4] A study by the Water Framework Directive Ireland awarded the Morell "Moderate" status for its suitability for macroinvertebrates.