River Irwell flood control scheme


River Irwell flood control scheme

Salford's flood prevention scheme uses open spaces for temporary water storage when levels get too high - showing that hard defences are not the only solution. Designed by Axis PED.

The city of Salford has experienced flooding for the last 150 years and more than 10,000 of its properties are in a high-risk flood zone, at risk of flooding once every 100 years. The watercourses that run through Salford include the River Irwell and the Manchester Ship Canal. With such flooding potential it is not surprising that over the last 20 years the council has been initiating ways of reducing flood risk. In the 1990s Salford City Council and the Environment Agency started building the River Irwell flood control scheme and more recently the council completed the Salford strategic flood risk assessment (SFRA), which now influences planning decisions.

Giving floodwater, and people, a place to go

The majority of properties in the city that lie in a high-risk flood zone are in the floodplain of the Irwell. Keen to prevent another major flood, the Environment Agency in partnership with the council, designed a new flood prevention scheme that recognised that traditional hard defences are not the only answer. This plan included temporary water storage areas which double as a public park and sports area for the majority of the time when they are not holding floodwater. The project was completed in 2005.

Salford’s strategic flood risk assessment

In the same year the city also completed its SFRA to assess land at risk of flooding within the city. This has been translated into a set of planning requirements to guide new development. They include ensuring that the floor level of buildings is above the predicted flood level; using open spaces to act as temporary floodwater storage areas; and ensuring that development does not increase the risk of flooding elsewhere. As a result of the SFRA the council is better informed about the impact of the predicted effects of climate change on the city.

Planning policy statement 25 (PPS25) on development and flood risk requires that all local planning authorities have an SFRA. Salford City Council is updating its SFRA completed in 2005 by engaging with the other nine districts of Greater Manchester (the Association of Greater Manchester Authorities) to produce a SFRA for the whole of Greater Manchester. This will help improve understanding of the cumulative impact of flooding across the sub-region and across river catchments, and how measures upstream can reduce runoff from reaching the River Irwell.