The Brosna continues flowing southwest through Clara, Ballycumber and Pullough.

From Ferbane it heads to Shannon Harbour, north of Banagher, where it joins the Shannon The river Brosna is popular for fly fishing and has stocks of brown trout as well as some salmon and grilse.

[5] However it has, in recent years, suffered somewhat from pollution problems due to its poor assimilative capacity and the discharge of untreated sewage in the Mullingar area during storm conditions.

There have also been discharges of pollutants, whether accidental or otherwise, such as one filmed at the bridge of Clonmore industrial estate in Mullingar.

More recently, in late 2008 the river was diverted from the N52 road beside Mullingar in order to accommodate a new roundabout and bridge.