Flood risk, drainage and water supply

When allocating sites and managing residual risk, plan makers need to consider the opportunities offered by new development to reduce the causes and impacts of flooding. The waterway network presents a potential opportunity to support and enhance development, with particular reference to water management.

Boat left stranded on land after a flood Boat left high and dry after a flood

With careful design, the waterways can provide sustainable options for site drainage from future developments. The managed nature of canal water levels, and the ability of our waterways to potentially accept surface water run-off, can help in wider consideration of flood mitigation measures.

Where a new (or modified) discharge is proposed, it will be reviewed to determine if the benefits to us outweigh the risks of acceptance. In the majority of situations, there is no obligation on us to accept discharges. There are many locations across the 2,000 miles of waterways that we care for that have agreements in place for us to receive such discharges.

Also take a look at our compiling your evidence base section in relation to our role as a reservoir undertaker and navigation authority.


Kings Cross development, London

With modification to eight weirs on the Regents Canal we were able to accept surface water discharge from this development. This removed the need for on-site attenuation in the form of a swale, which enables the public open space to be fully used.

Water supply

Our waterways also have a role in water supply, transferring water from place to place.


The Gloucester & Sharpness Canal is used to supply half of the city of Bristol’s water.

Last date edited: 19 November 2020