The Rivers Trust have produced a guide to practical advice on the design and maintenance of constructed wetlands for the purpose of mitigating urban diffuse pollution. See: Urban Wetland Design Guide – CaBA (catchmentbasedapproach.org)

The aim of this guide is to provide comprehensive and practical advice on the design and maintenance of constructed wetlands for the purpose of mitigating urban diffuse pollution. It is based on the London Borough of Enfield’s track record of delivering urban wetlands in a variety of settings. The subject area is complex and, in some areas, still the focus of ongoing research so where appropriate we have provided pointers to further information and support. The ability of wetlands to clean water that passes through them is proven but, as with all treatment systems, they have their limitations and there are often conflicting design considerations between optimising pollution control and biodiversity and amenity value. It is important to stress at the outset that their use should be considered part of a wider strategy for managing surface water quality that also includes source control measures. There are a number of different types of constructed wetlands that can be employed for pollution control. The focus of this guide is on simple surface flow systems which are passive, driven by gravity, and require relatively little maintenance. This guide is intended for anyone who is interested designing wetlands to improve water quality, particularly landscape designers looking for an introductory guide for designing in urban scenarios. Click here to access the guide