Rural Water Allocation and Quality
by Mikaela Hearne
Water from private bores is a vital source within Western Australia, particularly for rural areas where scheme water is unavailable and rainfall is unreliable. This water resource is also important for developers and miners within these rural areas.
If you are a local farmer, new property owner, developer or upcoming miner in Perth and are wondering how to gain access to clean, available water in your area, you are not alone. All rural property owners and developers require available water for their routine farming, gardening, household or construction activities. Where some uses of bore water (i.e. stock water supplies, irrigation, washing clothes and flushing toilets) do not depend heavily upon the quality of the water, other activities such as processing and drinking require raw bore water to be treated, disinfected and tested as suitable.
Water from rain and inland water systems seeps through layers of soil and rock to underground areas. This is commonly known as groundwater. As water moves further down, it separates into layers at various depths and in different areas. These different areas are then referred to as confined and unconfined aquifers. Bores drill into the aquifers and extract water from them. Groundwater quality, capacity and availability from within these aquifers vary from region to region.
Recent climate modeling from the Bureau of Meteorology shows a rising temperature (approx. 0.2-0.8°C) across most of the state and falling rainfall trend across WA, and over 90 % of the global climate models for the South West and Central West regions within WA suggest a much hotter and drier future (DWER, 2019). Since the 1970s rainfall has been on a steady decline (up to 200mm/a) due to a southward shift of winter storm systems and a greater frequency of high-pressure systems. Another notable climate driver within WA is the Indian Ocean Dipole (IOD) which when in positive, causes less rainfall within WA (BOM, 2020).
Due to the vast size of WA and the varied climatic influences across the state, the Department of Water (DWER) accesses the needs of these climatic regions independently from each other.
So how does this drier climate impact our local groundwater resources? With less rainfall, our other water resources, such as dams and shallow groundwater have become less reliable. Due to this DWER has identified alternative water sources for the state, including desalination and waste-water treatment plants, in order to supply and supplement areas within WA.
Increased groundwater abstraction to make up for reduced inflow to dams, and the decline in recharge from rainfall has resulted in lower groundwater levels in parts of the Gnangara groundwater system, this system is heavily relied upon for Yanchep, Gnangara, Wanneroo, Swan, Mirrabooka, Gwelup and Perth groundwater areas and includes a portion of the Gingin groundwater area. Therefore, the total use of water from this source needs to be reduced significantly to ensure a more sustainable and managed abstraction and recharge of the groundwater system.
Many people are not aware that DWER develops Water Allocation Plans for separate regions within the State and these plans manage our water by outlining how much water can be abstracted from groundwater and surface water resources while safeguarding the sustainability of the resource and protecting the water-dependent environment.
Due to some of Perth’s water resources being out of balance from climate change, it can be more difficult to obtain a license for the construction of a bore and abstraction of groundwater on your property in some areas.
All licenses are issued and considered under the Rights in Water and Irrigation Act 1914. A 5C licence will be required where you want to “take water” from a watercourse, wetland, confined or artesian underground water source. If you are looking to construct or alter a well / bore, then you will need to apply for a 26D licence. There are exemptions and several additional permits which may apply to the type of water you require taking from. These include the following:
Firstly, you need to determine whether you have access to bore water already or whether you need to construct a well, use surface water or interfere with the bed and banks of a watercourse.
The DWER Website provides advice for those planning for their water needs at https://www.water.wa.gov.au/licensing/water-licensing/do-i-need-a-licence-or-permit.
It is important to note, that the transfer of a property through sale does not automatically transfer across licences to “take water” associated with the property. In addition, if the water resource in your area has reached its allocation limit then your application for a new licence to take water could be rejected and you would need to consider alternative choices. Your options if you recently purchased a property include;
In order to determine, what water allocation is available in your areas, you can check out the Water Register, https://maps.water.wa.gov.au/#/webmap/register; include your address or region all the current licences and availabilities for the area will be mapped. This database will also provide adequate information on ownership of nearby properties and how much water is allocated to each licence, this will assist with your negotiations, potential leases and trades.
Ok, so now you have a licence (or exemption) and access to a bore resource, now its time to consider the quality of the water. Private water supply sources make up around 80% of all water used in WA. Water from this source can appear clean, fresh and aesthetically pleasing, however it can be contaminated with microscopic and dissolved contaminants that have filtered through the soil and rock layers into the water table below. These same contaminants could also drain into the bore casing over time.
Rural bores can become contaminated by site activities, from neighbouring properties or by natural processes (salination). Contamination is most likely to be detected in bores where the groundwater is near the surface and there is significant rural or industrial activity in the catchment. Sources of potential contamination can include; natural occurring salts and metals, sewage and animal waste, matter leached from stormwater, chemical spills and leaks, agricultural chemicals, pesticides and fertilizers.
Bore water accessed from unconfined aquifers is generally suitable for watering lawns, gardens, irrigation, stock watering purposes and construction activities, such as dust suppression. All fruit and vegetables watered using raw untreated bore water, should be washed prior to consumption. If you are drawing water from beneath or near a known contaminated source or site, the water is likely to contain contaminants and should be tested and if required, treatment prior to any use. To determine suitability of your bore water a simple field test can be conducted. It is recommended that your bore water be tested by a professional.
Where bore water is being used to drink, cook or shower or the bore water displays any of the following signs, it should be subject to treatment.
The department of water does not guarantee that the water quality of the bore water allocated via a licence is suitable for any particular use. So as a landowner there are several things that you can implement to protect your water quality:
With so many other things to be concerned about when you live on a rural property and are involved with agriculture or property development, worrying about water quality from your bore can be a nuisance. However, Integraflow offer you tailored solutions for the water quality testing and treatment of your bore water. Our team of environmental specialists can assess your needs and carry out the required tests. We are equipped with in-house laboratory facilities and work closely with a NATA-accredited Laboratory to ensure your samples and testing is carried out according to Australian guidelines. Upon receiving your results, we prepare the best treatment systems and options for you based on your water characteristics, its end purpose and ongoing monitoring requirements.
If you are a large property owner, a developer or in the agriculture business we can also help you with water treatment plans on a large scale, including determining the licences and permits that you will require, the available water allowable at your property or development, water projection models and the organising of an experienced Australian Drilling Industry Association licenced driller to carry out construction of new or additional bores /wells.
Any advice and direction Integraflow provide you in relation to your water treatment needs, will be in accordance with Department of Water, Australian Drinking Water Guidelines, Department of Health and the Department of Agriculture and Food.