Surface water run-off from the two developments would be managed using sustainable drainage measures (SuDS), designed in accordance with current best practice.

 

The preliminary drainage strategy proposes that surface water run-off from the developments would be collected in a series of new ponds and swales across the site, and then discharged into the Rhyne and the existing wet ditches at a rate equivalent to the existing rate for the undeveloped site.  There would therefore be no increase in flooding anywhere beyond the site.

 

The ponds and swales would be designed to accommodate a 1-in-100-year storm event and allow for a 45% increase in peak rainfall to account for the impact of climate change.  Where space precludes the use of swales, attenuation storage for surface water will be provided by permeable paving overlying a porous sub-base stone.

 

The proposed drainage strategy of ponds and swales to collect surface water

With regard to foul water drainage, a foul sewer crosses the southern part of the site from east to west.  It is anticipated that foul water drainage from the two developments can be connected to this existing sewer.