Molesey Weir improvements
Updated 11 March 2015
© Crown copyright 2015
This publication is licensed under the terms of the Open Government Licence v3.0 except where otherwise stated. To view this licence, visit nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@nationalarchives.gov.uk.
Where we have identified any third party copyright information you will need to obtain permission from the copyright holders concerned.
This publication is available at https://www.gov.uk/government/publications/river-thames-weir-and-lock-improvements/molesey-weir-improvements
Molesey Weir B is part of the Molesey weir complex located upstream of Hampton Court Palace. The weir helps to control water levels between Teddington and Sunbury. At present, Molesey Weir B uses old double-leaf buck gates (a vertical sliding gate).
There are 2 walkways that go across the structure. One walkway gives access to the gates to operate the weir and the other allows residents of Ash Island to get to their homes and houseboats.
Structural assessments by the Environment Agency have confirmed that the weir structure needs to be completely replaced. The weir is in poor condition, with significant corrosion. The operating mechanism for the weir gates also needs to be modernised.
These refurbishment works will keep the weir in good working order, reduce future maintenance needs, and ensure the continued long-term use of the weir.
Latest update
The Environment Agency has successfully completed Year 1 construction work at Molesey Weir B. The operational handover of the 4 new radial gates happened on 20 December 2013.
They can only work on half of the weir at a time, so they will do Year 2 construction work from March to November 2014.
The Environment Agency can’t work during the winter months because they need to manage flood risk. They keep the weirs fully functional when there are higher flows. If there are high flows during the summer months (when they are on site) then they have plans to restore the full capacity of the weir.
The main compound at Hurst Park will remain on site during the winter months even when the Environment Agency are not working. The temporary footbridge to Ash Island will remain open to the residents until Year 2 construction is finished.
The Environment Agency will install a cofferdam (a temporary structure within the river made by putting in steel sheet piles) as part of Year 2 construction work. The cofferdam will be closed off to create a dry and safe working area.
The installation of the sheet piles will start around the middle of March 2014 for approximately 6 weeks. This is before we begin dismantling and replacing the remaining weir structure and fish trap. The fish trap will be replaced with a new fish pass.
Contact
If you would like to sign up for email updates, or would like to receive the environmental report, please email: weirimprovements@environment-agency.gov.uk.