The river rises at Calderhead on Heald Moor, west of Burnley in Lancashire.

There are two rivers Calder at the source: one flowing west to join the Ribble and going on to the Irish Sea, and the Yorkshire Calder.

The Yorkshire Calder flows eastwards for a distance of around 56 miles, through Todmorden – where it forms part of the Yorkshire-Lancashire borderHebden Bridge, Mytholmroyd, Luddendenfoot, Sowerby Bridge, Copley, Elland, Brighouse, Cooper Bridge where it joins the River Colne, and on to Wakefield, joining the River Aire at Castleford. From there, it flows on into the Humber and the North Sea.

The river drains an area of approximately 365 square miles. It falls from 1300 ft above sea-level to around 50 ft when it joins the Aire. There are around 800,000 people living in the catchment of the river.

See Lake Calder.

At Black Pit, Hebden Bridge, it is joined by Hebden Water.

At Sowerby Bridge it is joined by the Ryburn. It is one of the few local rivers with enough power to turn the wheels of the mills.

At Brooksmouth it is joined by the Hebble.

The river is only navigable in parts – see Calder & Hebble Navigation.

Major river crossings are at Elland and Brighouse.

The name Keldre is recorded in 1439, and is variously derived from Celtic roots – cal or casill and dwr (water) - to mean any of:

Another suggestion is that the name derives from 2 tributaries: the Cal & the Der which meet at Todmorden.

During the 19th century, when it powered so many mills along its banks, the river was said to be:

The hardest worked river in all England

In 1865, a Royal Commission on River Pollution reported that

The rivers Aire and Calder throughout their whole course [from Todmorden to Castleford] are abused, obstructed polluted, poisoned, corrupted and clogged by refuse from mines, chemical works, dyeing, scouring and fulling worsted and woollen goods, skin cleansing and tanning, slaughterhouse garbage, and the sewerage of towns and houses

Fish in the Calder

Today, there are several species of coarse fish in the river, including barbel, bream, brown trout, carp, chub, dace, grayling, gudgeon, ide, perch, roach, silver bream, tench.

The last salmon in the Calder was caught in 1850 before increasing pollution did considerable damage to the wildlife. On 8th April 1881, a trout weighing 12 ounces was caught in the Calder at Carrfield, Portsmouth, Todmorden.

In June 1975, 40,000 fish died as a result of pollution in the river.


The Top-of-the-poops website monitors and reports the raw sewage discharged into English & Welsh rivers.

In 2021, the Calder was Number 2 in the list of the worst rivers for sewage spills in the Yorkshire Water area. The Calder was Number 2 in the entire national report (to the Severn which came Number 1

See Calder Future, Cal, Der and Royd

This & associated entries use material contributed by John Ogden

© Malcolm Bull 2024
Revised 16:28 / 8th April 2024 / 6886

Page Ref: MMC777

search tips advanced search
site search by freefind