Mereway Weir Replacement

Closes 17 Jul 2020

Opened 17 Jul 2019


Updated on: 14 October 2019

Welcome to the Mereway project information webpage. Please click the links below to the FAQs at the bottom of the page.



We are planning to replace the existing weir on the River Crane located at the end of Mereway Road. Please see the location on the map below. The weir is coming to the end of its 30 year lifespan and it and its mechanisms will have to be replaced.

Above: Location of Mereway Weir and picture of the current structure

Alongside the weir replacement, we are also hoping to construct a fish pass through Mereway Nature Reserve connecting the Duke of Northumberland's River and the River Crane. This will allow fish to access parts of the River Crane that have previously been limited or not available. This will attract further wildlife and create greater biodiversity in the surrounding areas.





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Above: Fishpass outline design in colour


What is currently happening?

We are currently preparing for the main weir replacement works which will be starting in November 2019. This will include a crane installed next to the weir to place the new weir into the river channel. River flows will be maintained by a bypass channel that exists in the bank. 

Local roads may be busier than usual whilst larger vehicles access the site. Before works start, letters will be distributed along Mereway Road and the surrounding area as well. You may see our construction consultants around Mereway Nature Reserve in the weeks leading to the works starting.

Official date for contractors to be on site is from Monday 11 November. This is to start the weir replacement works.

Future works

Replacement of the weir will go ahead in November 2019 with the fish pass construction to follow. Once we confirm dates, we will update this webpage and provide notification to the public.

Construction of the fish pass through Mereway Nature Reserve will start as soon as planning permission has been granted.

Who have we involved in our planning?

  • Richmond Borough Council
  • Friends of the River Crane (FORCE)
  • Friends of Kneller Gardens
  • Crane Valley Partnership


What is Mereway Weir? Mereway Weir is an automatic tilting weir on the River Crane, designed to maintain flows for the Duke of Northumberland's River and the River Crane.

What does it do? It keeps a steady flow into the River Crane and into the Duke of Northumberland and is a key flood defence asset for the Twickenham area.

What is it being replaced? It is now at the end of its lifespan, including the parts that operate it. A new weir and operating systems are required to make sure it keeps working as normal.

Who are the Environment Agency working with? We are working with Richmond Borough Council, Friends of the River Crane, Crane Valley Partnership and Friends of Kneller Gardens.

Why is a fish pass needed? A fish pass will be beneficial as the weir currently acts as a barrier to migrating fish from the Crane and Duke of Northumberland.

How will this benefit me? The weir currently protects over 500 residential properties from a high risk flood event. Updating the current weir will continue this protection. The fish pass will act as another channel, linking the Duke of Northumberland and the River Crane through Mereway Nature Reserve. The pathways will be preserved as well as further pathways next to the new channel.

Will I still be able to walk through during the works? Yes, walking routes will still be accessible with diversion signs in place.

Will I still be able to drive through during the works? Yes, if there are any restrictions, these will be hours at a time rather than full days.

What trees will be removed? Some trees in the fish pass footprint will have to be removed. We have consulted with Richmond Borough Council and have altered design to protect more mature trees.

How will we be notified about the works? Information will be available on this webpage so please check every so often. Other forms of communication are also planned:

  • Update letter drops for surrounding residents
  • Further posters around Mereway Nature Reserve
  • Social media

Contact Us

If you have a question about the project or would like further detail please email below:

Other Useful Links

Visit our website here to find out more about what you can do to reduce the impact of flooding on you and your property.

Sign up to flood warnings here.

Find out about your rights and responsibilities of owning a watercourse here.

If you have been flooded from a public sewer, please complete Thames Water's sewer flooding questionnaire on their website here and return it to them at the address on the form. 


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