The connection between Douglas village and this river was long recognised. The placename ‘Douglas’ is an anglicisation of ‘Dubhghláise’, meaning ‘Black Stream’. ¹ Thus this small, fast-flowing riverulet gave Douglas its name. ²

Rising in Castletreasure, the river gathers speed as it flows down the hill towards Donnybrook. The early industrial history of Douglas is intimately connected with this river. Manufacturing businesses had to be located next to rivers and streams because water was an essential part of production. Swift rivers like this one provided water power to drive machinery. In 1801, Besnard’s mill in Douglas was the first in Ireland to spin flax on mechanised looms, driven by the power of this river. Flax was a thriving industry in Cork during the Napoleonic Wars so Besnard built another mill in Ravensdale. By 1806, two mills were situated on this river. When the water wheels were replaced by steam engines in the 1860s, the river provided the water from which steam was made.

Today the river is confined and corralled by concrete, as planners attempt to direct it away from businesses and roads. The village that once depended on the river has covered it over and ignored it. But it remains an important wildlife haven. Wooded areas along its course provide wildlife habitat corridors for animals such as otters. Walkers in the Ballybrack Woods, also known as the Mangala, are unlikely to meet these secretive creatures, but the river and its banks are an important otter habitat. Brown trout are also found in the river, and the heron we often see standing in the water testifies to the marine life in this suburban rivulet.