We know the site has some areas of surface water flooding, particularly along the southern boundary in the existing ditch.

We appointed local civil engineer Canham Consulting to undertake a detailed flood risk assessment and prepare an initial drainage design. The proposed strategy will improve drainage, and protect against flooding even in rare 1-in-100-year events. We’ve also applied a ‘climate change factor’ to ensure the worst possible case has been considered.

The proposed drainage strategy is to attenuate water in a basin located in the south eastern corner of the site and discharge it slowly into existing surface water sewers. All water that falls onto hard surfaces will either be conveyed towards the basin via gullies and a piped system or filter through permeable paving before entering the piped network to ensure that the water is removed effectively.

The basin will not typically have water in it, it’s designed to only be needed after large storm events when the water has built up. During a rare 1 in 100 year plus climate change event, the water may reach the top of the basin. In the event of an even greater storm, the basin may overflow. In which case it’s been designed to flow into the existing ditch on the southern boundary (which should no longer typically fill with water due to the new basin).

More detail is available in the Flood Risk Assessment submitted as part of our planning application. A maintenance strategy has also been submitted to ensure everything continues to work as it should.