Questions from the MRREC 1. How much water is currently being taken from each well/bore and region in the South West? This is a question for the water regulator the Department of Water. Please note information on bores is publically available and can be accessed online through the Department of Water s Water Register. 2. What are the ecologically sustainable limits of water withdrawal now, over the course of the fifty year plan and beyond? This is a question for the water regulator the Department of Water. The water requirements of South West ecosystems have been determined by the Department of Water and were one factor considered when the Department of Water set the sustainable allocation limits outlined in the South West Groundwater Areas Allocation plan (2009). The sustainable allocation limits have been set to minimise the potential impacts to wetlands and river in the future, while sustaining reasonable growth in the region. Extensive information on the South West Groundwater Areas Allocation plan is available on the Department of Water s web page http://www.water.wa.gov.au/managing+water/allocation+planning/south+west+regi on/south+west+groundwater/default.aspx The Water Corporation works within the sustainable allocation limits set by the Department of Water in their allocation plan. 3. Is the current level of extraction above or below the ecologically sustainable limits? This is a question best answered by the water regulator the Department of Water. The Department s recent evaluation of the allocation plan states that the current allocation limits are sufficient to protect existing users rights and the environment. The evaluation can be found on the Department s web page: http://www.water.wa.gov.au/publicationstore/first/105640.pdf
4. Relating to the proposed scenarios what would be the increase in Groundwater extraction? The South West Groundwater Areas allocation plan (2009) sets aside a volume of water from the South West Yarragadee and other aquifers to support future public water supplies for south west towns. Groundwater options for Water Forever: South West are about accessing this public water reserve. 5. Would these amounts exceed the ecologically sustainable limits? As outlined above these amounts are already included in the South West Groundwater Areas Allocation plan (2009). 6. Is there robust peer-reviewed quantitive mapping and modelling of hydrological interactions in and relating to the study area (South West region), both at current levels of human extraction and for all proposed options please? Such modelling would be essential in determining ecologically sustainable limits for Groundwater Dependant Ecosystems and sustainable supply for human settlements. The data would need to include projected changes to rainfall due to climatic variation. The above question applies to both Water Corporation and Department of Water planning. If such modelling exists can it please be made available to the public? If such modelling does not exist we would recommend adoption of the Precautionary Principle and NO further additional groundwater extraction in the study area. This is a question for the water regulator the Department of Water. The Department of Water sets the sustainable limits in the South West Areas Groundwater Allocation plan. A number of investigations, including modelling, have been used to help develop the plan and all the investigation reports are available on the DoW web page. http://www.water.wa.gov.au/managing+water/allocation+planning/south+west+ Region/South+West+groundwater/default.aspx
7. Will the desalination be powered by Renewable Energy (RE)? The Water Corporation operates approximately 15 desalination plants across the State. For the two large seawater desalination plants (Perth Seawater Desalination Plant (PSDP) and the Southern Seawater Desalination Plant (SSDP) near Binningup) the Water Corporation purchases power from wind and solar farms to help offset their ongoing energy requirements. This decision was made as part of the detailed project approval process. If we were to develop desalination plants for the south west any decision on power would be made as part of the project definition and approval process. 8. For what reasons is the Desalination option marked as only environmentally manageable rather than favourable? When looking at carbon impacts and ways to reduce your carbon footprint the principles are, in order of importance: 1. Reduce or avoid energy use 2. improve efficiency of your energy use 3. offset impacts. Desalination uses energy to treat and convert seawater into drinking water. This energy use is not environmentally favourable but purchasing renewable energy offsets is one way of managing this impact. Significant energy efficiencies have also been achieved at both the Perth and Southern Seawater Desalination Plants, which set new world benchmarks for energy use by plants of their kind. Additionally, desalination plants require construction of seawater intakes and brine discharge pipes in the marine environment, construction of a building, and pipes and pumps to move the water from the ocean to the towns where water is needed. Any impacts from these activities would have to be managed.
9. What would the likely financial cost of the Desal' plants and their RE systems be please? Desalination is more expensive than traditional water sources such as dams or groundwater and financial costs depend on a number of factors including: location of the plant size of the plant type of desalination technology used integration costs (eg. pipes and pumps) 10. Given the likelihood (or inevitability) of finding significantly sized new sources of water is it likely that the Minister of Water, the Department of Water and Water Corp' will prefer the "Local Groundwater" option to "Desalination" due to short term financial reasons even if "Local Groundwater" usage is realised to be environmentally negligent? (I hope not.) The Water Forever: South West project does not replace the water licencing process run by the Department of Water (the regulator) who assesses whether licence applications are acceptable. The goal of Water Forever: South West is to develop an understanding of all options available to help meet future local demand be it water efficiency, recycling or new water sources. 11. Again in the Additional Water Sources section there are options of "Integration of Regional Schemes", "Water Carting" and "Water Trading". What would the proposed or likely actual source of these three water transportation options be please? Water Trading refers to the process of trading water through the DoW licence process. There are various forms of trades available short term or long term trade of an existing licence. Of particular interest to the Water Corporation are opportunities to trade water that is available due to water efficiency improvements this could be either surface water or groundwater.
Water carting is only applicable for small towns as a way of ensuring safe water supply. The actual source water could come from any Water Corporation water supply that is available and depends on the location of the town. Integration of regional scheme relates to joining towns to provide additional water security. The water supply would depend on the locations of the towns. 12. Catchment clearing to encourage additional rainfall run-off into streams and dams is included as an option in the Additional Water Sources section of the Water Corp. brochure. Please note that catchment management involves reducing the number of tree stands and understorey in the forest, not clear felling of the catchment. 12a) Would such proposed clearing be exclusively understory vegetation? No. The forests which have been logged (and mined in some cases) are overgrown with young trees which are using a lot of water. Catchment thinning involves selectively thinning the forest and some understorey. Habitat trees are retained. 12b) How many hectares would potentially be affected by such a proposal? There are 7 catchments, within the Water Forever: South West study area which could potentially undergo catchment management. Catchment management is best suited for high rainfall zones and within these 7 catchments approximately 35% of the area could be suitable for catchment thinning. The specific area would be determined if a proposal was progressed. 12c) When considering this option how will the needs of aquatic biodiversity be weighed against potential losses to terrestrial biodiversity and specifically fauna habitat and food supply? This is done in an environmentally sustainable way in line with the Forest Management Plan and with monitoring carried out. Research from Wungong Catchment trial did not show any adverse impact to the environment. As outlined above, habitat trees are maintained and the catchment is not cleared but selectively thinned.
12d) As streams are Groundwater Dependant Ecosystems would it not make more sense to avoid extracting more groundwater rather than clearing vegetation? The majority of catchments considered for thinning are outside the south west groundwater allocation area. 13. In the "Water Recycling" section of the Water Forever (SW) brochure there are "Groundwater replenishment" and "Managed Aquifer Recharge" options. How will the water be treated/cleaned please? Will the water meet Australian, state and local government standards for drinking/re-use? The treatment process used for groundwater replenishment or managed aquifer recharge would be determined as part of preliminary investigations on a specific proposal. Treatment options include microfiltration, ultrafiltration, reverse osmosis and ultraviolent disinfection. The Water Corporation is committed to effective management of its drinking water supplies to provide a safe, high-quality product that consistently meets the Australian Drinking Water Guidelines, consumer and other regulatory requirements. 14. In the "Water Use Efficiency" section of the brochure what are the factors which make "Water Restrictions" only environmentally manageable rather than favorable please? The two day a week sprinkler roster and the winter sprinkler ban are now permanent water efficiency measures. Water restrictions such as a total summer sprinkler ban may result in a loss of gardens and green spaces. As these habitats support a variety of wildlife, provide a cooling effect in urban areas and help take up carbon dioxide and filter the air this is not considered a favourable outcome. 15. In the "Water Use Efficiency" section of the brochure there appear to be many useful practical initiatives. Local groups such as Living Smart, Transition Towns and Environment Centre's could partner in delivering some of these options.
Reducing water use is a step we can all take to reduce demand on our water resources. Water efficiency measures require a high level of community support so please tells us your favourite ideas and what you think would work in your community.