Drainage program for 2017–18
The city has been installing, upgrading and extending its comprehensive drainage system for many years. Current drainage design principles and practices advocate for stormwater discharge at the source though infiltration, rather than collecting and conveying through long lengths of underground pipes to an outlet. Fortunately the ground conditions and low groundwater levels in Subiaco allow for effective infiltration, which is achieved through the installation of soakwells and other structures, such as drainage cells. This has the combined benefit of reducing the volume of stormwater discharging to the river or other outlet, increasing infiltration into underground aquifers and effectively increasing the volumetric capacity of the city’s drainage system.
As with city's other assets – such as roads, parks, furniture and buildings – condition assessment of the below-ground drainage network is critical. In 2017–18 budget, there is an allocation of funding for the condition assessment of the city's drainage network. This is an essential asset management task to ensure pipe failure does not occur to the city's ageing drainage pipes and to provide for a systematic renewal program.
In addition, there is an allocation for extensive modelling of the existing drainage network. This modelling will lead to the following outcomes:
- replacement of low-capacity pipeline sections with larger-diameter pipes to prevent flooding in high rainfall events
- provision of piped drainage systems to streets that are not adequately equipped
- reduced potential for property flooding, erosion and safety hazards to motorists caused by wide gutter flows
- progressive implementation of innovations to the drainage system, based on advancements in this field.
The completion of the condition assessment of the city’s below-ground pipe network and comprehensive modelling will ensure that a holistic five and ten-year drainage works program can be developed to address both renewal and upgrade requirements.
More information about the city's proposed drainage works can be found in the 2017–18 budget. Should you have any queries, please contact us.