Part 1 of a series of 4 books that set out Landcom’s draft Water Sensitive Urban Design Policy for all of its developments. This draft policy set aims to give Landcom staff, consultants and private sector partners an overview of WSUD guiding principles, practices and objectives. It should be borne in mind that this draft policy is shaped by the kinds of development work undertaken by Landcom.
Under the policy, a WSUD Strategy is required for each Landcom development that seeks to protect aquatic ecosystems and water resources, and minimise the impacts of urban development on the urban water cycle.
Book 1 sets objectives for water conservation, stormwater pollution control and mitigation of increased flows arising from urban developments. These are setout in the figure below, an excerpt from page 9 of Book 1.
With regards to water conservation targets the draft Landcom policy proposes a ‘baseline’ target that equates to BASIX requirements.
Stormwater Pollution Control targets are based on the statewide water management objectives for new developments - but actually set quantitative targets - “Baseline”, “Performance” and “Stretch”.
Stretch stormwater targets are “considered necessary to protect the receiving environment from the negative impacts of urban development.” They are included in the document "to demonstrate the gap between environmental objectives and the extent to which these can be met by 'best practice WSUD'; and to encourage performance beyond standard targets.
Flow Management Targets only apply to greenfield sites when a natural streams exist downstream of the proposed development. The Stream Erosion Index is used within NSW Growth Centres Commission areas to quantify hydrological objectives that seek to mitigate the impacts of development on the geomorphic stability of streams. Further explanation of these flow objectives is provided in Book 2 of the Landcom set (pages 25-28).
In addition to the targets set out in the table, mandatory requirements for each Landcom development include requirements to:
- identify alternative water sources to meet at least 80% of all demand for public open space (irrigation, water features, pools) etc; and
- Dual reticulation supply systems for non potable water.
Landcom project managers are directed to refer to Books 2 and 3 of the set for further guidance on available options to meet the targets. Book 2 covers the project-specific WSUD Strategies that are to be undertaken at the same time as a proposed development’s masterplan or structure plan.
Additional sources of guidance on WSUD concept design are suggested by HCCREMS below.