Craig Zerk, East Ballina
As an engineer with over 45 years’ experience working in the water supply industry, I support the new water Strategy proposed by Rous Water and I am opposed to the Dunoon Dam.
There are some very significant reasons for favouring groundwater over construction of a new dam downstream of the existing Rocky Creek Dam.
Economically, groundwater offers the lowest Net Present Value and can be sequentially staged over decades to meet the needs of a growing population. By comparison, the dam involves a huge up-front cost (the estimate as at 2020 was $220 million – but we know that the cost of these kinds of projects always blows out significantly). The dam is actually sized to meet the needs of a more than 70 per cent increase in population to the year 2080 but would need to be funded by the present ratepayers (even though we already have enough water for our present needs).
Building another dam a very short distance downstream of the existing dam (which is currently our main water source) is not a wise decision since it is highly desirable that we diversify our supplies to address risks associated with drought, natural disasters, and acts of terror.
Developing the groundwater resources progressively in line with population growth also allows us to change the strategy in response to changes in circumstances and adopt technologies (such as indirect potable re-use) that will inevitably emerge over coming decades.
Given the great uncertainties associated with predicting how our climate will change, the reliability of the dam cannot be accurately quantified, so its ability to meet future needs is uncertain. Having a flexible and staged water strategy would allow us to respond better to such uncertainty.
Development of our largely under-utilised groundwater has virtually no impact on the environment. By comparison the dam requires clearing 57 hectares of predominantly native vegetation including Big Scrub Rainforest. According to Wikipedia, ‘the Big Scrub was the largest area of subtropical lowland rainforest in eastern Australia. It was intensively cleared for agricultural use in the 19th century by settlers. Less than one per cent now remains’. The dam will also remove habitat and corridors for a range of important species, for example the koala, glossy-black cockatoo and pPlatypus.
The dam will also flood items of very significant aboriginal cultural heritage value.
The dam storage would cover an area of 253 hectares and will lock up another 234 hectares of buffer around its perimeter. This would sterilise a significant area of potentially highly productive agricultural land.
Rous Water has now made the right decision to start tapping into our vast and largely under-utilised groundwater resources to meet the growing water supply needs of our region.
In spite of this, in January this year the following Ballina Shire Councillors voted in favour of asking Rous County Council to ‘continue with further investigations as to the viability of the Dunoon Dam proposal’: Sharon Cadwallader, Eoin Johnston, Sharon Parry, Stephen McCarthy, Phillip Meehan, and Ben Smith.
I urge all residents of the Ballina, Byron, Lismore and Richmond Valley local government areas to lodge a brief submission with Rous Water prior to 28 May to oppose the Dunoon Dam and give support to the current proposal to utilise our groundwater resources as proposed in the Future Water Strategy.