Working on behalf of the Environment Agency, Team Van Oord has successfully completed the first phase of a two-year project to replace a weir structure at Molesey on the River Thames.
Molesey Weir B is part of the Molesey weir complex located upstream of Hampton Court Palace. The weir helps to control water levels on the Thames between Teddington and Sunbury.
There are two walkways across the structure. One gives the Environment Agency access to the gates to operate the weir and the other allows residents of Ash Island to get to their homes and houseboats.
The weir was in generally poor condition, with significant corrosion and an outdated operating mechanism for the weir gates. Structural assessments confirmed that the weir structure needed to be completely replaced.
Under the scheme of works the current 15 “buck gates” will be replaced with seven radial gates, and the canopy will be replaced. The new weir will include an adjacent fish pass in place of the existing fish trap.
The work is being carried out in two phases in 2013 and 2014. No work is carried out during the winter months because the weirs must be fully functional when there are higher flows in order to manage flood risk. If there are high flows during the summer months when work is taking place there are contingency plans to restore the weir’s full capacity.
Year one construction work has been successfully completed and the operational handover of four of the new radial gates took place on 20 December 2013.
Barry Holt, Team Van Oord project manager for the scheme, said: “As part of the year two works we will install a cofferdam – a temporary structure within the river comprising steel sheet piles – which will be closed off to create a dry and safe work area.
“The installation of the sheet piles will start around the middle of March and will take approximately six weeks.
“We will then begin to dismantle and replace the remaining weir structure and fish trap which will be replaced with a new fish pass.
“These refurbishment works will keep the weir in good working order and reduce future maintenance needs.”
Speaking on behalf of other residents, ‘Suleman’, said: “The workers were all extremely polite and considerate. They went out of their way to minimise disruption and respected residents’ privacy. The close proximity of the works to our homes could have been a nightmare but they kept the island and paths clear at all times.
“I expected daily complaints from the residents but did not hear a single complaint. Instead, the project became a source of interest to us and a point of conversation. The positive reception was entirely down to the team.
“All the workers, from labourers to managers, were extremely friendly, knowledgeable and willing to keep us all informed of the process and the next steps. It was also very pleasing to see how proud each of them was with the project.”
The second phase of work will be carried out during the period March-November 2014.
20 January 2014