8.1 Introduction

SuDS are designed to mimic natural drainage systems and are more resilient and cost effective than conventional drainage methods. Surrey, like the south-east of England more generally, is at increasing risk of water stress, rising temperatures and flooding. Sustainable water management plays an essential role in alleviating these risks as well as helping meet wider climate resilience aims. SuDS also help placemaking strategies and deliver wider benefits. They must be considered from the earliest stages of the design process.

Well-designed SuDS can:

• Significantly reduce surface water runoff, reducing the pressure on sewage and drainage infrastructure thereby reducing sewages spills into watercourses;
• Reduce the risk of flooding and provide resilience to future climate change;
• Improve water quality through filtration and natural breakdown of pollutants;
• Assist with groundwater recharge;
• Help create greener, calmer, more beautiful streets;
• Bring redundant areas of hard surfacing or highways land into productive use;
• Be more cost effective than traditional hard engineered drainage solutions; and
• Enhance biodiversity and provide urban greening.

Figure 8-1: Some of the variety of forms and features of SuDS (Credit - NMDC)