[3] On the Burnley side of the park it passes Unity College and Fulledge Recreation Ground, and under the Hand Bridge which carries the A671 Todmorden Road.

It is again culverted, first as it is crossed by Centenary Way and then again at Parker Lane, before running under Chaddesley House and Manchester Road next to the Town Hall and Mechanics Theatre.

It collects Barden Clough near Royle and is shortly after joined by Pendle Water at Burnley Wastewater Treatment Works (also known as Duck Pits) on the edge of Reedley Hallows parish.

Continuing its winding route it is then crossed by the old railway viaduct at Martholme, and shortly afterward it is joined by Sabden Brook, just before flowing under the A680 Accrington Road at Cock Bridge.

[3] The name Calder is relatively common and thought to originate from the ancient British language, the first part may be the ancestor of the Welsh word caled (hard), with the second being *dubron (water), giving a possible meaning of the rapid river.

A weir built in the 1950s to allow Padiham Power Station to take water from the river was removed in 2010 along with other improvements to aid the passage of fish upstream.

Built for Whalley Community Hydro, the site became operational at the end of the year and is expected to generate an average 345,000 kWh of electricity annually.