Re-Use Irrigated Private Plantations
Transforming waste into resources is an important part of Victorias move toward sustainability. And transformation is exactly whats happening when we combine wastewater management with timber production.
Victoria currently has some 500ha of plantations that are irrigated with wastewater. These plantations are important because they can utilise the water and plant nutrients that are collected from industrial, residential, commercial and agricultural areas. Nutrient-rich wastewater that reaches natural waterbodies, has the potential to contribute to algal blooms and other problems.
These plantations are also important as a future wood resource. They can contribute to growing a forestry and forest products industry that can generate income for private landowners and jobs for regional Victoria.
Nationwide information on plantations irrigated with wastewater have been collated by the CSIRO into the Sustainable Effluent-Irrigated Plantations: An Australian Guideline.
Still, the land-based treatment of wastewater is a rapidly evolving science and it is important that everyone involved is kept abreast of domestic and international developments such as progress toward bioenergy production.
Developments may take many forms provided aspects such as species and irrigation method are appropriate to the region and site conditions. Wastewater sources may also vary including:
- animal feedlots
- nutrient-rich agricultural drainage
- food & fibre processors
- municipal treatment plants
The Re-Use Irrigated Private Plantations Initiative
In recognition of these issues and opportunities, from 2001 to 2004 the Victorian Government funded an initiative for the accelerated development of Re-use Irrigated Private Plantations.
The aim of the initiative was to provide significant water quality benefits and forest industry growth, by developing a substantial plantation resource based on efficient and sustainable utilisation of nutrient-rich wastewater.
A combination of communication, research and incentives were used to achieve gains in:
- management of nutrient-rich wastewater
- knowledge of sustainable systems
- investment in regional forest resources
- communication between stakeholders
With support from this project, the CSIRO a Victorian addendum to their Australian Guidelines which were a product of the Wagga Wagga Effluent Plantation Project. This involved improving the models used in the design of such developments and associated infrastructure.
Also with the support of this project, the Forest Science Centre continued its work with the harvesting and measurement of sustainability trials near Shepparton. They also participated in the Bioenergy from Forests and Plantations initiative and provided technical advice to incentive applicants.
As the major component, the project offered incentives to wastewater managers across the state to encourage the establishment of re-use irrigated private plantations.
The project provided advice on 17 potential developments, and from these financial support was provided for the establishment of 150 hectares of re-use irrigated private plantations and associated infrastructure.
Priority was given to developments that:
- maximised water quality benefits
- maximised forest industry growth
- showed sound project planning and management
- were innovative or had wider impacts
- Department of Sustainability & Environment
- Department of Innovation, Industry and Regional Development
- EPA (Victoria)
- Victorian Water Industry Association
Case Studies
Goulburn Valley Water urban water
Land based re-use is a key component of Goulburn Valley Waters wastewater management facility north of Shepparton. Rather than discharge to the Goulburn River, reclaimed water is utilised on irrigated pastures and crops, agroforestry and plantations. More than 70 hectares of trees have been established since 1988, using more than 6 megalitres per hectare per year (this equates to 600mm of rainfall).
Included is a trial site where the Forest Science Centre is conducting research on biomass accumulation and system sustainability. Harvesting in 1999 generated pulpwood, poles, mulch and firewood as initial products. There is even potential for the development of commercial biomass energy generation at this location. Based on experience from Shepparton, Goulburn Valley Water has developed irrigated plantation sites at Seymour and Broadford.
Red Gums - agricultural
The Downey property lies at the end of a small catchment that flows into the Goulburn River. The Warrigal/Yambuna creek system has been constructed to reduce watertables by removing excess water from agricultural properties. The water that flows past their property is variable in quality and often contains high levels of nutrient and salt.
The Downeys established their first plantation of River Red Gum in 1994. Under licence they pump water from the system and use it to irrigate their trees. This way they are able to capture some of the nutrients as fertiliser. Flooded Gum and Sydney Blue Gum are also among the species that they irrigate in their 17 hectare plantation. The Downeys have since expanded their plantation and utilise more agricultural drainage water.
Further Information
A guidelines pack that was initially prepared for the project is still available for new re-use irrigated private plantation developments. With sustainability a major aim, developers are encouraged to prepare a plan incorporating the use of best practice with regards to nutrient, water and forest management.
For further information on Re-use Irrigated Private Plantations, please contact:
Rhodey Bowman
Private Forestry Officer
Department of Primary Industries
Private Bag 1, Tatura 3616
Phone: (03) 5833 5957
Fax: (03) 5833 5971
rhodey.bowman@dpi.vic.gov.au
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