VICTORIAN aqueducts in Nidd and Barden that continue to supply 160 million litres of water per day to Bradford and Ilkley are in the final stages of a £3.6 million makeover to extend their lifespan into future decades.

The aqueducts date back to 1860 and were originally commissioned to supply the rapidly expanding city of Bradford during the Industrial Revolution for drinking water and wool processing. To this day, they still play a vital role in supplying homes in Ilkley with water as they transport it from reservoirs in Nidderdale and Barden to water treatment works in Bradford that supply Ilkley.

Following a £3.6 million three-year programme of improvements, the repairs to the aqueducts are now in their final year.

Mark Broady, Yorkshire Water project manager, said: “The aqueducts are fantastic feats of Victorian engineering but they are both well over 100 years old and needed some repairs.

“Our partners have been hard at work since 2014 and the project should be complete by the end of 2017.

“The Nidd and Barden aqueducts together transport 160 million litres of water to water treatment works in Bradford every day, which is enough to supply nearly 300,000 properties.

“This project will ensure the security of water supplies to Bradford and Ilkley for years to come.”

The Nidd aqueduct took four years to construct (1894 to 1902) and transfers 130 million litres of raw water every day from Angram and Scar House Reservoirs in Upper Nidderdale along 40km of tunnels, aqueducts and bridges to Chellow Heights treatment works in Bradford.

The aqueduct is lined with concrete and inside it measures more than six feet high.

Completed in about 1860, Barden aqueduct transfers about 30 million litres of raw water per day from Lower Barden reservoir and water collected from the moors near Burnsall to Graincliffe treatment works, also located in Bradford.

The water passes through 22kms of tunnels and 42-inch diameter aqueducts, constructed from Yorkshire sandstone blocks.

Engineers from OVIC, Ken Rodney Construction and Mott MacDonald Bentley have been involved in this project.

It has involved minor structural remedial works, such as resetting of keystones and re-grouting, to major structural works, like the installation of internal structural bracing and the full replacement of some sections. The work has been carefully co-ordinated to minimise the impact on the water supply to Bradford’s water treatment works to ensure customers do not go without water.

Mott MacDonald Bentley will next month start working on a section of the Nidd aqueduct near to Skyreholme.