Protection of in-stream biota from urban impacts: minimise catchment imperviousness or improve drainage design?

Abstract

Urbanisation is a looming global threat to in-stream biodiversity, but the best approaches to mitigation are unclear. This paper asks if the protection of in-stream biota, in particular macroinvertebrate assemblages, is dependent on the sequestration of catchments from urbanisation, or if protection in urbanised catchments can be achieved through better drainage design. In-stream macroinvertebrate assemblage composition was assessed for 16 catchments spanning a rural-urban gradient. Catchment imperviousness and drainage connection (the proportion of impervious area directly connected to streams by stormwater pipes), together with other possible driving factors, were assessed as explanatory v..