International approaches to the hydraulic control of surface water runoff in mitigating flood and environmental risks

This paper compares and contrasts a number of international approaches to the hydraulic control of surface water runoff from new development and redevelopment, known as sustainable drainage systems (SuDS) or low impact development (LID). The paper provides a commentary on the progress and current status of national standards for SuDS in the UK to control the frequency, flow rate and volume of runoff from both frequent and extreme rainfall events, and the best practice design criteria presented in the revised UK CIRIA SuDS Manual, published in November 2015. The paper then compares these design criteria and standards with those developed and applied in China, USA, France and Germany and also looks at the drivers behind their development. The benefits of these different approaches are assessed in the context of flood risk mitigation, climate resilience and wider environmental protection objectives, including water quality, morphology and ecology. The paper also reviews the design approaches promoted by the new SuDS Manual and internationally for delivering additional benefits for urban spaces (such as recreation, visual character, education and economic growth) through multi-functional urban design