The Liffey has a modern catchment area of 224 square kilometres (86 sq mi) which has been modified by human activity, specifically diversion for irrigation.

[3]: 25  This irrigation diversion originates at the Poatina Hydroelectric Power Station's tailrace and enters the river near Bracknell.

[4] Water quality in the lower reaches is affected by agricultural run-off and for a small length by discharge from a sewerage plant at Carrick.

[5] The river was originally known as Tellerpangger by the aboriginal inhabitants of the area, the Panninher clan of the North Midlands Nation.

To reduce the incidence and impact of flooding both were raised substantially leaving the nearby Carrick Mill's ground floor far below the road level.