Woodhouse Mill Regulator Emergency Works

Flood Control, Sheffield UK

Woodhouse Mill Regulator Emergency Works

Just before Christmas, Sheffield was deluged with heavy amounts of rainfall and the subsequent mechanical failure of the Woodhouse Mill Regulator threatened multiple properties and the surrounding road network with floods and disruption. Qualter Hall was contracted by BAM Nuttall to support emergency works to secure the flood gate, control the flow of flood water and manage long-term remedial works.

A counterbalance failure meant that the barrier dropped down into the River Rother whilst it was flowing at a high level due to heavy rainfall. This directed a large amount of water into the surrounding flood plains, risking flooding across surrounding urban areas, businesses and residential properties at Woodhouse Mill, and the surrounding Rother Valley.

Qualter Hall worked with blueprint designs supplied by KGAL Consulting Engineers, to fabricate two large steel lifting frames over 3 days, to support the lifting of the gate into its required position.

An emergency response team supported by Qualter Hall, gathered on-site on Wednesday 18 December and worked to establish a controlled 2m lift of the gate. Against dwindling daylight, they overcame several challenges to complete the lift fully, as planned.

Jon Precious, Project Manager for BAM Nuttal said: “Because of the amount of water, the gate had to be lifted in small increments. This was to ensure the safety of people and infrastructure both upstream and downstream as a significant backlog of water was released. The gate lift made a huge difference to the river levels experienced at the regulator” (shown in the chart).

“The available telemetry data suggest that the levels dropped circa 3m in 3 hours throughout the gate lift operation. Sheffield experienced prolonged, heavy rain overnight and into the morning of the following day, and the subsequent readings suggest that there may have been some nervousness locally had the gate not been lifted as planned, as levels within the river Rother began to rise again because of the weather.”

“We were approached by several residents and local stakeholders throughout the day who wanted to pass on how pleased they were that the gate was being lifted before the Christmas period. We spoke to individuals who had been flooded previously who commented that their anxiety around possible flooding had eased now that the gate had been lifted.”

The regulator gate was locked, made safe and remained suspended on air hoists throughout the Christmas period. Lifting equipment was left in position as a mitigation measure, with additional lifting slings installed to ensure the gate remained in position into the New Year. Regular monitoring was undertaken by BAM over the holiday period, to further control the site.