Holistic Water Cycle Management in Priority Growth Area in Sydney’s West by Managing the Water Cycle Strategies of Individual Precincts

The most significant development in Sydney is taking place in Priority Growth Areas (PGA) along the South Creek corridor, Sydney’s West. The Water Cycle Management (WCM) Strategy is a key component in the development of PGA. WCM strategies for PGA precincts development carried out in isolation were reviewed. Their shortcomings were addressed through a regional 2D TUFLOW hydraulic model. This 2D regional model was used to control the cumulative impacts of Leppington precinct development. The Urban Site Detention (USD) guidelines were prepared to maintain pre-developed hydrological behaviour. USD guideline for 50% Annual Exceedance Probability (AEP) was used to mitigate waterways stability impacts reducing erosion and Total Suspended Solids (TSS), while 1% AEP USD guideline was used to mitigate flooding. The adoption of the USD guidelines enhanced the stability of bed and bank, biotic habitats and ecosystem health of creeks. Water quality requirements were addressed by Water Sensitive Urban Design (WSUD). WSUD and the reuse of stormwater planning were based on MUSIC modelling. Climate change impacts were considered. The precinct planning integrates stormwater management with liveability by reducing flood risks to properties and infrastructure and increases the safety and security of residents. This paper will discuss the application of updated strategies in WCM for Leppington precinct and its achievements in holistic WCM strategy in PGA development.