The site is mostly located within the Environment Agency’s Flood Zone 1, which carries the lowest risk for fluvial, tidal and coastal flooding. However, there is a limited section of the southern part of the site that is located within Flood Zones 2 and 3. The flood risk in Flood Zones 2 and 3 originates as a result of an area of lower ground where the watercourse crossing the site becomes culverted as it reaches the urbanised area of Witney, along Hailey Road, before discharging into the River Windrush.

Given that this part of the site is located in Flood Zone 2 and 3, and has been identified as an area that has experienced historic flooding, we are not proposing to include built development in these areas of the site. The Consortium’s proposals will include a package of measures to improve the current flooding situation, creating a betterment for the whole community.

Surface water drainage

Surface water run-off from rainfall from the developed site will be managed through the introduction of a new Sustainable Drainage System (SuDS). This system has been designed to withstand peak rainfall with an allowance for an additional 40%, ensuring it is fit for the future.

The watercourse continues through the central corridor of the site, which forms a surface water flooding valley that will be retained and significantly enhanced to create new habitats for wildlife while continuing to provide an important drainage function.

The proposed Sustainable Drainage Systems (SuDS) from the developed site will include swales, ditches, basins and ponds, that will:

  • Capture surface water before releasing it at a rate lower than that which reflects natural systems, decreasing the peak and velocity of flows reaching the Hailey Drain culvert
  • Control the water at source and re-use where possible
  • Offer opportunities to deliver landscaping and wildlife enhancements in various areas of the site
  • Follow the natural topography of the site and move water to attenuation basins through the central ecological corridor, as well as along the boundaries with New Yatt Road and Hailey Road, to reduce the flood risk associated with the Hailey Road drain
  • Naturally clean the water, before it enters the local watercourse system We have carefully considered both surface water and foul water drainage in the proposals to ensure that there is no impact on the surrounding area.