The Condition of urban streams in northern Sydney

This paper outlines the methodology, application and analysis of a rapid urban stream assessment tool, the Rapid Riparian Assessment (RRA) within the Ku-ring-gai Council Local Government Area, Sydney. The tool was developed to improve the understanding of riparian processes and broader environmental condition with an urban context. The results assist environmental management through the identification of causes and processes of change and degradation, inturn allowing the ability to direct policy, strategy and operational resources. The RRA has been carried out in all streams under the management and control of Ku-ring-gai Council, in total 221 kilometres, incorporating 288 reaches were assessed. It was found that 61% have a condition rating of good or better. Only 1% of reaches assessed were rated as very poor. The results suggest that urban stream condition within this local government area is better than predicted for typical urban streams. This may be attributed to the large number of bushland corridors that help to maintain the riparian zone in conjunction with the geomorphology, predominately incised gullies dominated by Hawkesbury Sandstone, that is relatively robust to urban pressures, consequently remaining relatively un-impacted. Sensitivity testing of the methodology and attribute weightings confirms the effectiveness of this tool.