The Canals and Waterways Problem

British Waterways owns and manages over 540km of navigable rivers and 2600km of canals which in turn interact with the major river basins and land drainage systems of the UK . Most of the canals were constructed more than 200 years ago, and are very vulnerable to flood events. Often the waterways cross different catchments and can thus transfer flows from one catchment to another. British Waterways also own and manage 89 reservoirs in the UK , some of which are managed entirely for flood storage.

Canals are usually "still" waters, and do not clean themselves as with flowing rivers, so pollution is a particular problem, for example from sewage backup from drains.

Canals generally operate with only 300mm of freeboard, and there are over 650km of embankments to be maintained. Overtopping of embankments, especially those over 200 years old, can lead to failure, which could have a catastrophic impact especially in urban areas.

British Waterways is very aware of the risk and has a system of sluices, weirs, pumps, and floodgates to control the flow into canals. They have a thorough system of emergency procedures that have worked well so far, but climate change is going to impose a major challenge to our 200-year old network of canals, and this challenge does not yet seem to be fully recognised by government.