Posted on November 5, 2015
Wandsworth Council has introduced a plan to remove the half-tide weir on the River Wandle at Wandsworth with the main goal to allow the tidal river to return to its natural state to support biodiversity in central London.
Funding for the project is being provided by Tideway, the company responsible for delivering the Thames Tideway Tunnel.
Sediment has built up behind Wandsworth half-tide weir over its 25 year lifetime. This build up has buried the natural gravel river bed under a deep layer of debris and silt.
Removal of the weir and these silt deposits will take out the barrier between the Wandle and the tidal Thames. Natural tidal action at the river mouth will scour fine, muddy sediment from the area and restore the gravel river bottom, restoring valuable subtidal and intertidal habitats for fish, invertebrates and wading birds.
HR Wallingford is helping Wandsworth Council to understand and minimize the impact of the weir and silt removal on the Wandle and Thames, and is working with regulators to ensure their requirements are fully understood and met.
Ecological and sediment surveys in the creek have been carried out and the results of these will help to inform an assessment of the potential environmental impacts (both positive and negative) of removing the weir.
Tom Matthewson, technical director at HR Wallingford, said: “Returning this section of the River Wandle to its natural state will have wide-ranging environmental benefits to the River Thames and its tributaries. We are working closely with the Marine Management Organisation, Environment Agency and Port of London Authority to ensure that their interests are also protected as part of this project. We aim to have consents in place to allow removal the weir to occur by the spring of 2017.”
HR Wallingford has been providing independent advice on the design and impact of developments on the tidal Thames for more than 60 years.