Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what assessment he has made of the potential merits of using river and canal dredging to tackle the flooding in South Yorkshire.

The Government’s flood risk management work focuses on where it delivers the greatest benefit to people and property. Dredging and other work to improve the river channel’s ability to carry increased flow (conveyance) often forms an important part of the Environment Agency’s (EA’s) maintenance regime. However the effectiveness of dredging in managing flood risk varies substantially for each stretch of river, depending on local conditions, and can actually make flooding worse if flows are quickened to towns and villages downstream. The EA assesses its value on a location-by-location basis, in consultation with local communities and organisations such as Internal Drainage Boards (IDBs) where appropriate.

The merits of dredging to tackle flooding in South Yorkshire are limited. The surrounding land and bed of the lower reaches of the river Don are flat with a very low gradient, meaning water drains slowly, and they are at or below sea level, which further slows drainage. If riverbeds were dredged lower than sea level, they would simply fill with water and would not reduce flood levels.