By reference to examples in the UK this paper examines the wildlife potential of reedbed treatment systems, both in their ability to act as pollutant buffers to protect or create downstream wetlands of conservation importance and as wildlife resources in their own right.
The constraints of size, structural diversity, pollution stresses and design criteria of constructed wetlands are evaluated in terms of wildlife conservation opportunities, and the more stringent water quality requirements for wildlife functions are discussed.
As a case study example, the paper examines in detail the South Finger Reedbed developed by The Wildfowl & Wetlands Trust. This system has been designed with the dual objectives of improving the quality of effluent from a large collection of captive wildfowl in order to buffer sensitive downstream wetlands and of creating a wetland habitat of nature conservation value. The performance of this system, constructed in 1993, indicates good treatment levels, with suspended solids reduction around 80% and BOD generally above 60%. In terms of wildlife performance the system rapidly evolved to support a broad range of vertebrate and invertebrate species.
The paper concludes that constructed wetlands for waste water treatment can be designed and managed to achieve optimal wildlife potential if approached from an ecological perspective as opposed to a strictly engineering viewpoint.