Mereway Weir Replacement

Closes 17 Jul 2020

Opened 17 Jul 2019


Updated on: 17 July 2019

Welcome – if you have found this webpage through one of the posters or letters notifying about works in your area, this is an overview of the project that the works are supporting.

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 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.

What is currently happening?

We are currently conducting ground investigations in Mereway Nature Reserve to see if the fish pass can go ahead. These will be ongoing from Monday 22 July 2019 until 5 August 2019. This will include digging holes to examine soil structure and creating shallow boreholes to observe water levels. You may have seen a recent poster in or around Mereway Nature Reserve informing about this.

Future works

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

This will include a crane installed next to the weir to place the new one into the river channel. River flows will be maintained by pipes between the work areas. This may occasionally impact access to Mereway Nature Reserve, but other routes will be signposted.

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 we get to see the designs? We will update this webpage once we have updated designs for the fish pass. We plan to visit Kneller Gardens soon for a drop in, so the designs, information and key project people are available to speak to. The date is to be confirmed and we will update here as well as through flyers.  

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:

  • 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. 


  • Recreational and commercial river users
  • Fishing clubs and representative associations
  • Members of the public with an interest in the river, the species and conservation
  • Businesses
  • Charities
  • Statutory organisations
  • NGOs
  • Members of the public
  • Elected representatives, including MPs
  • Local councils
  • Academics
  • All water abstractors
  • Environment Agency customers
  • Local authorities
  • District and parish councils
  • Environmental bodies
  • Land owners
  • RFCCs
  • Elected representatives, including MPs
  • Water companies
  • Members of the public
  • Recreational and commercial river users
  • Community groups
  • Flood action groups
  • Environment Agency colleagues
  • Lead Local Flood Authorities
  • Local Risk Management Authorities
  • Flood Resilience Forums
  • Members of the public
  • Town and parish councils
  • Regional Flood and Coastal Committees
  • Internal Drainage Boards
  • Engagement specialists/operational staff in Natural Resources Wales, local authorities and other risk management authorities


  • Flood management
  • Water resources
  • Water quality
  • Habitats and wildlife