Driffield - Wansford Lock Refurbishment
The lock at Wansford is the only lock along the Driffield Navigation which had not been fully restored by teams of volunteers.
The top gates were in a seriously dilapidated state and in danger of collapse. Failure of these gates would inundate the fish farms downstream and drain the section above the lock, causing severe loss of wildlife habitat.
There was no bypass channel (bywash) around the lock to carry excess flow during periods of heavy rainfall. As a consequence the balance beams of the dilapidated gates were overtopped by over 300mm during the June 2007 floods and adjacent properties were inundated.
The Driffield Navigation highlighted to WREN the urgency of the required works, not only to remove a further obstacle to navigation but also to create a bywash (flood alleviation channel) around the lock to minimise any further risk to adjacent properties, as well as improving the aesthetics of the area and access to the lock for the general public, including anglers, tourists and walkers.
The scope of the works included:
• Coffer dam the southern upstream section where the bywash inlet will be constructed.
• Excavate and install the bywash pipe-work, 1000mm diameter, diverting the flow around the lock.
• Excavate the necessary footings and create the bywash inlet structure, incorporating stop-planks to enable water level to be controlled.
• Dam off the upstream entrance to the lock.
• Remove the old gates and clean out the lock.
• Cut stop plank grooves in the upstream and downstream masonry.
• Restore the sills, top and bottom.
• Fit the existing new top gates and fit new cast iron heel plates.
• Remove invasive vegetation from the masonry of the local walls, restore and re-point as necessary.
• Remove the old bottom gates.
• Erect coffer dam around location of bottom gates.
• Produce new gates and fit.
• Remove coffer dams and make good the lock surrounds.