Harvesting the Storm

RPS’ Environment team in Perth, Australia has recently been commissioned to undertake Detailed Design of the Stormwater Harvesting and Water Efficiency Project for the City of Greater Geraldton (CoGG).

CoGG was formed in July 2011 as a result of the merger of the former City of Geraldton-Greenough and Shire of Mullewa. Geraldton is a coastal city located approximately 430km north of Perth, and serves as the central hub for a range of industries within the mid-west region including tourism, mining, agriculture and fisheries. A number of major projects planned for the region have resulted in a forecast for a substantial increase in population of the region over the next ten years.

As a result, CoGG currently plans to service a population of 100,000 into the future. CoGG recognises the importance of the role of water to the community, particularly in light of the forecasted significant population increase and the development that will need to support this growth.

Current potable supplies for the City of Geraldton are obtained from groundwater drawn from borefields located approximately 50km south-east of Geraldton. In addition to potable supplies, groundwater is used for a range of activities including the irrigation of parks and gardens within the city. However, groundwater resources in the region are limited and to ensure a sustainable water supply for the future, the need for their careful management is well recognised.

The CoGG has long been aware of the importance of managing the region’s limited water resources in order to provide for healthy communities and sustainable growth. To this end, a number of initiatives and studies have previously been undertaken by CoGG with the intention of establishing information regarding water resources in the region, and defining management procedures and strategies for their efficient, sustainable and equitable use.

The City was successful in securing funding from the National Water Security Plan for Cities and Towns element of the federal government’s Water for the Future initiative in 2011. The funding was for a Stormwater Harvesting and Water Efficiency Project (SHWEP) developed by the City, with federal funding to be matched by funding contributed by the City.

Water Efficiency Project
In delivering the required scope of works specified under the Water Efficiency Project, the City of Greater Geraldton required RPS to provide specialised scientific and horticultural services to support the investigation and evaluation of scheme irrigated public open spaces (POS), and to identify practical and cost-effective measures to improve water use efficiency whilst maintaining landscape amenity. The irrigation auditing and system evaluation component of the project proposed by RPS will assist in identifying a range of best practice initiatives that can be implemented across all bore-irrigated POS in the City to further maximise efficiencies and conserve water resources.

Stormwater Harvesting Project
RPS’ Environment team has previously completed the Preliminary Investigations and Concept Design Development reports and now RPS has been commissioned to provide the Detailed Design element of the Stormwater Harvesting Project. In the coming months RPS will advance the design of the Stormwater Drainage Retrofit within the Geraldton CBD with the aim of diverting stormwater flows from approximately 50% of the Durlacher Street catchment area and subsequently facilitate infiltration of the diverted stormwater within Maitland Park, which will allow subsequent abstraction of the water as an irrigation resource.
RPS will also advance detailed designs on the modification and retrofitting of existing stormwater sump networks to achieve sufficient infiltration rates and also provide an abstraction water supply point.