Irwell

The Irwell is a river in the North West of England, running through Lancashire and Greater Manchester. It is approximately 40 miles (65 kilometers) long and ultimately drains into the River Mersey via the Manchester Ship Canal. In parts of its course the river forms a boundary between historic Lancashire and Greater Manchester, reflecting its long association with local administrative borders.

The river’s headwaters rise in the Pennine foothills of the West Pennine Moors and the surrounding upland areas. It flows generally southeast, passing towns and urban areas such as Bolton and Bury before continuing toward Salford and Manchester. In its lower reaches the Irwell passes through industrial and post-industrial landscapes and contributes to the Manchester Ship Canal’s water system. The canal, in turn, provides a navigable link to the River Mersey.

Historically, the Irwell supported textile manufacturing and other industries, with mills and mills fleets exploiting its water power and transport links. From the 19th into the 20th century the river suffered severe pollution, prompting substantial cleanup and restoration efforts in the late 20th and early 21st centuries. Today the Irwell is valued for flood management, recreation along its banks, and wildlife habitat, with efforts aimed at balancing urban use with ecological health.

Etymology regarding the name Irwell is uncertain; it is likely derived from earlier languages spoken in the region. The river remains a notable geographical feature of northwest England, shaping local history, settlements, and landscape.