Work on vital safety improvements at Yorkshire Water’s Butterley reservoir in Marsden  with a £5 million project to replace the spillway will start early next month.

A previous inspection of the spillway by an independent Panel Engineer highlighted the need to adapt the spillway to ensure it continues to meet with legislation, in particular, the Reservoirs Act 1975.

The stone spillway, designed by Thomas Hawksley, is a major engineering achievement and was completed in 1906. It controls the flow of water from Butterley reservoir, safely ensuring it does not overtop and damage or erode the embankment.

Mott MacDonald Bentley, will raise the spillway walls and replace the steep section (towards the middle of the spillway) with a straight slope to ensure flood waters are contained within the channel.

Lee Laherty, Yorkshire Water Project Manager said:

 “We know that the spillway is a much-loved local landmark and we’ve worked hard to design a solution that's sympathetic to the local surroundings, whilst ensuring it meets legal requirements.”

“We are going to replicate the existing small steps within the spillway, retain two thirds of the existing spillway walls and re-use coping stones where possible. We'll clad the raised walls with natural sandstone and hope to retain the majority of existing keystones.”

The massive engineering project will take until the end of 2017 to complete.