Abstract:
Water Sensitive Urban Design has much in common with the New Zealand (NZ) practice, Low Impact Urban Design and Development (LIUDD). In New Zealand, both terrestrial and aquatic ecosystem protection and re-creation are essential elements of greenfield developments that conform to LIUDD. This paper reports on comparative New Zealand catchment studies over 7 years for conventional and Water Sensitive Urban Design subdivision at low/countryside (2000 – 5000 m2 lots) and average/urban (400 - 500 m2 lots) residential densities. Subdivision, re-vegetation and house construction are now nearing completion. Catchment characteristics are related to the health of in-stream macro-invertebrate communities as indicators of stream and catchment condition. Results for in-stream indicators are compared to region-wide values and show the ecological superiority of WSUD/LIUDD catchments. Indicators of stream ecological health in treatment catchments have improved for two urban streams and up to three countryside residential streams during the subdivision and house construction period contrary to normal expectations for conventional urban development.