Eurobodalla Integrated Water Cycle Management Strategy

Eurobodalla Integrated Water Cycle Management Strategy
membrane filtration and disinfection at the Tomakin STP would be more cost effective than
sewer mining.
Considerable effort is being applied worldwide to the development of appropriate
technologies and management systems for on-site wastewater management systems.
There are a variety of new on-site and decentralised treatment systems coming on to the
market which provide potential to undertake water recycling on a household, neighbourhood
or subdivision scale at a similar or less overall cost than a fully reticulated water recycling
system from a centralised treatment system. A number of these systems have been
successfully implemented in the USA. Factors important for a successful system include a
careful evaluation of the site capability to ensure that there will not be adverse health and
environmental impacts, and the adoption of centralised management of decentralised
treatment and recycling systems.
The bulk supply of reclaimed water to large urban landscaping and industrial customers is
usually more cost effective than residential reuse. Due to the small number of large
commercial and industrial consumers in the Eurobodalla Shire, the potential for commercial
and industrial reuse is minimal.
It might be possible to justify the development of a dual reticulation reclaimed water system
for Rosedale and other new development areas when account is taken of:
The benefits of increased yield in droughts
The economic benefits of freeing up peak day capacity in the system to serve other
users
The garden water benefits to householders, particularly during droughts
The environmental benefits of reduced freshwater diversions above the tidal limit,
and
The environmental benefits of reduced reclaimed water discharges to the estuary
or the ocean.
Previous analysis indicates that the capital cost associated with a second reclaimed water
reticulation network is about $2 560/lot. This cost includes the plumbing costs. The annual
operating, maintenance, compliance and monitoring costs are about 10% of the capital
cost. Therefore to service 1 000 new lots would cost around $2.6m.
Agriculture – Cropping in Natural and Constructed Environment
Agricultural cropping in the natural environment refers to the conventional practice of broad
acre farming. There are many examples of ‘cropping in the natural environment’ agricultural
reuse schemes in Australia, however most of these are undertaken in areas with lower
rainfall. Examples include irrigation of sugar cane crops along the drier parts of the
Queensland coast, the major scheme to irrigate dairy pasture now under construction in the
northern Shoalhaven area near Nowra in NSW, and irrigation of horticultural crops at
Virginia in South Australia.
Agricultural cropping in a constructed environment includes nurseries and open and
covered hydroponic systems. Although there are currently no such enterprises within
Eurobodalla, Council could promote these types of enterprises given their high margins and
the water use of these types of enterprises. Additional information on these types of
enterprises is contained in appendix N2.
The shire-wide reclaimed water reuse review has identified the Moruya and Tuross River
flats as the two major dairy and agricultural regions in the shire. The Moruya region
comprises approximately 1 000 ha of dairy land and the agricultural and the Tuross region
contains about 1 500 ha.
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