MWRPP Report 24.10: Assessing the protection of Sunbury streams and headwaters from urbanisation: An interim report.

<p dir="ltr">Conventional approaches to stormwater drainage degrade urban stream hydrology, water quality, geomorphology, biological integrity and ecosystem function. This long-term project aims to assess if stormwater runoff from new urban development in the Sunbury region can be adequately retained, used and treated, to protect or restore receiving stream ecosystem structure and function. The implementation of contrasting approaches to stormwater management across the Sunbury urban growth areas (Integrated Water Management (IWM) using principles of stormwater management for stream protection (Walsh et al. 2016), versus the mandated 1999</p><p dir="ltr">Best Practice Environmental Management standards, BPEM), paired with a robust monitoring program, will ultimately allow for a clear comparison of the effects on receiving water ecosystems. This comparison will focus on differences between business-as-usual (i.e. BPEM) and current best practice following IWM principles. With high ecosystem values present in Emu Creek running to the east of Sunbury, standard urban development using 1999 BPEM standard is likely to have significant negative impacts on both Emu Creek and its smaller tributaries. Monitoring began in 2018 and urban development across the Sunbury region is rapidly progressing. This interim report aims to provide an overview of the project implementation and data collected to date. We specifically seek to assess current stream conditions and identify recent declines in stream condition associated with urban development which has out-paced broader development and implementation of the IWM stormwater harvesting scheme. We combine hydrological, water quality, biological and ecosystem functional data from a range of receiving streams to assess stream condition.</p>