Is is feasible to reduce annual bore water use below annual rainfall?
January 7, 2017 at 1:01 am #1498
Has anyone calculated whether the bore water we use for gardens is greater than the recharge from annual rainfall? If it is, we are not acting sustainably because we are drawing down the water table. It would be a great goal to reduce our bore water use to less than the recharge from rainfall. What would we have to change to make this happen?
January 8, 2017 at 1:50 pm #1501
This is a great question, and this issue causes major problems for the communities that use groundwater and government agencies that are responsible for managing water resources. In many parts of the world, including Western Australia, groundwater resources are stressed and the amount drawn out by bores exceeds the amount that recharges through rainfall.
In WA, the Department of Water regulates the amount of water that can be extracted by licensed bore users through a “groundwater allocation plan”. The current Gnangara groundwater areas allocation plan is available at http://www.water.wa.gov.au
This Plan is updated occasionally and a recent plan shows that groundwater storage depletion in the Superficial Aquifer over the last 29 years has been approximately 700 GL. In other words, we have used 700 GL more groundwater from shallow groundwater resources than has been recharged through rainfall, clearly not a sustainable approach. (700 GL is about 10 times the annual abstraction of groundwater by private domestic bores).
The long term impacts of this are that ecosystems, wetlands and lakes dry up, river flow reduces, and domestic and other bore users run out of water.
Options to change this situation are outlined in the Gnangara groundwater areas allocation plan. In the case of individual private domestic bores, you can do your part by ensuring you reduce bore water use, adopt sustainable water practices, including water efficiency measures, and only watering in cool periods of the day.
Please also refer to the “Guideline on bore sustainability” on this web site.
- This reply was modified 2 years, 10 months ago by Peter Addison.
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