Salinity in the Port Phillip and Western Port Region

SALINITY IN THE PORT PHILLIP AND WESTERN PORT REGION

FAQ’s

For additional copies of this summary brochure or to obtain a copy of the Additional information about salinity, salt tolerant plant species and Salinity Report maps in Arcview or Mapinfo call the PPWCMA offi ce on grazing management go to the Cooperative Research Centre and it’s 03 8781 7900. linked sites at http://www.crcsalinity.com/aboutus/index.php The Port Phillip and Western Port Salinity Report can be downloaded from the PPWCMA website at: http://www.ppwcma.vic.gov.au. Advice on whether you have a salinity problem we recommend you seek advice from a qualifi ed advisor. Neither the PPWCMA nor DPI are qualifi ed to give this advice.

Acknowledgements

The Port Phillip and Western Port Salinity Report is a synthesis of information contained within the Draft Port Phillip and Westernport Salinity Management Plan (unpublished). The DPI led project that developed the Port Phillip and Westernport Salinity Management Plan commenced in 2002 and resulted in the draft Salinity Management Plan submitted to and accepted by the Port Phillip and Westernport CMA in November 2007. The Port Phillip and Westernport CMA gratefully acknowledges and appreciates all of the precluding work which has increased our collective knowledge on salinity in this region. In particular we would like to thank the Department of Primary Industries for leading the development of the draft Salinity Management Plan, especially Lindsay Hyde, Steve Lottkowitz, Vivian Amenta, Julie White and Xiang Cheng. We would also like to thank the consulting team responsible for producing the Groundwater Flow Systems report, upon which many actions are based, all of the groups and organisations who have prepared past Salinity Management Reports in the region. Finally, we would like to thank those organisations who gave their time to consult with in the design of this Salinity Report; Melbourne Water, Bass Coast Landcare Network and Frankston City Council. Publication details Port Phillip and Westernport Regional Salinity Management Report. ISBN: TO BE ADVISED © The State of Victoria, Port Phillip and Westernport Catchment Management Authority, 2007. This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968. Disclaimer This publication may be of assistance to you but the Port Phillip and Westernport Catchment management Authority and its employees do not guarantee that the publication is without fl aw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. This brochure is a summary of an investigation into salinity in the Port Salinity Management Zones contain high risk areas Phillip and Western Port region. The investigation was commissioned by the Port Phillip and Westernport CMA (PPWCMA) and undertaken The report identifi es twelve Salinity Management Zones, as shown in • Identifi ed and quantifi ed where assets (such as native fl ora and Figure 2, that were further investigated. These areas were identifi ed fauna, aboriginal heritage sites, wetlands and existing and future by the Department of Primary Industries. based mainly on the depth to watertable and the presence of salinity urban infrastructure) are most at risk; discharge sites. The investigation looked at the causes, effects and treatment options The full Port Phillip and Western Port Salinity Report and it’s fi ndings • Defi ned and priced treatment actions that could be implemented to of salinity in the region. The resultant report is designed to: can be downloaded from the PPWCMA website: For each Salinity Management Zone, the report has: reduce the risk of salinity.

• Explain where salinity may threaten infrastructure, private http://www.ppwcma.vic.gov.au. • Identiﬁ ed the groundwater ﬂ ow systems operating in the area; property, waterways and other natural resource assets; and • Mapped where water is entering the groundwater system and where • Assist councils, Landcare, community groups and government salinity discharge is most likely to occur; agencies to assess potential salinity risks and consider effective responses.

Depth to watertable Location of Salinity Management Zones

SMZ4

SMZ5 SMZ12

SMZ2 SMZ3

SMZ1

SMZ11 SMZ12 SMZ6

SMZ7 Salinity Mgt Zones Legend SMZ12 1 - Balliang Local Government 2 - Rowsley Valley SMZ8 3 - Rockbank Depth to Watertable (m) 4 - Upper Maribyrnong 0-2 5 - Whittlesea/Nillumbik 6 - Bunyip/Pakenham 2-5 7 - Cranbourne/Clyde 8 - Mornington Peninsula 5-10 9 - Bass Valley 10 - Philli Island 10 - 20 SMZ9 11 - Wyndham/Melton Growth Corridor SMZ10 >20 12 - Irrigation Zones

Why salinity is an important issue for this region Groundwater fl ow systems Using the describe and explain the behaviour of groundwater. There are three Over the past 170 years vegetation clearance and landscape The report identifi es the following areas of shallow water tables: types of groundwater fl ow systems modifi cation have resulted in saline groundwater tables rising in many • all fi ve of the corridors designated for future urban growth in the in this region; local intermediate areas across the region. ‘Melbourne 2030’ strategy; Salinity Report and regional. High saline water tables could have signifi cant impacts upon • horticultural land on the Mornington Peninsula and at Werribee and agriculture, horticulture, urban infrastructure, tourism, rivers and the The three groundwater fl ow Bacchus Marsh; The Port Phillip and Western Port Salinity Report, along with it’s maps and data, natural environment over the coming decades. systems respond differently to can be used to assess salinity risk and to design salinity treatment programs. • the river valleys of Werribee, Maribyrnong, Plenty and Cardinia salinity treatment. Local treatment Salinity problems are most likely when the watertable is close to the A risk assessment should consider: Creek. actions are most successful at surface. By understanding how deep the region’s watertables are • Depth to watertable (indicating the potential risk); altering watertables when local from the surface, the report has identifi ed which areas may be most Thirty-two rivers and streams in the region are known to have rising groundwater fl ow systems are likely to develop salinity problems. Areas with watertables less than salt levels, and the health of unique Ramsar wetlands in both our • Groundwater fl ow systems (indicating the likelihood of success of local action); operating and least successful two meters from the surface have an immediate risk of developing a region’s bays could be affected by this in the coming years. • Quantity, quality and importance of assets (indicating the urgency of action); and when regional groundwater fl ow salinity problem. These areas may already be showing symptoms systems are present. of salinity. Figure 1 provides an overview of the depth to watertable • Resourcing required to implement actions (indicating the ability to act). across the region.