Answers to how opening the River Roch in Rochdale town centre will help mitigate flood risk

Photo: Margaret Curry

The River Roch uncovered in the Town Centre in 1996

Part of the rationale behind opening the river in the town centre is because the Environment Agency want to alleviate a flood risk. Rochdale Online has therefore asked, on behalf of our readers, the council and the Environment Agency questions relating to the flood risk, how opening the river helps and also what financial support has been forthcoming from the Environment Agency.

1. What is the likelihood of flood without the opening and how will the opening reduce that risk?

The modelling system used by the Environment Agency to predict the risk of a flood shows that there is a 3.33 per cent chance of the River Roch flooding. The proposal to remove sections of the culvert to reveal more of the river cannot prevent floods entirely, but will mitigate their impact. This is because river water can be pumped more easily back onto the river and away from buildings. It will also reduce the depth of the water that builds up by getting it back into the channel sooner.

2. Is the design being changed to help alleviate a flood?

Flood mitigation has always been a key element of the design. The revised design retains the flood alleviation benefits of the original by including modest changes in surface levels to ensure that flood water enters the river channel as soon as possible and to compensate for retaining the upstream part of the culvert that we proposed to remove in the original design.

3. How much more money has the Environment Agency put up?

In total the Environment Agency will contribute £1m to the scheme. This is an increase of £460,000. This increase is in two parts. Firstly, an additional £100,000 to increase the environmental improvements to the river. The balance of £360,000 for flood alleviation was provided by the Regional Flood and Coastal Committee.