What is groundwater?
Groundwater is the water located beneath Earth's surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water.
Water saving tips
Use the links below to find out about water saving tips to help you conserve water at home and reduce overall water usage.
Saving water in the home
Saving water in the garden
The City's sprinkler use
Why are the sprinklers operating in the rain?
From time to time residents may see sprinklers in parks and street gardens running while it is raining. It would be reasonable for residents to assume that we are wasting water.
We are allocated by the Department of Water a groundwater abstraction volume of 7500 kilolitres per hectare to irrigate our reserves and streetscapes. We allocate a percentage of this overall amount for each month of the year. The percentage allocation is based on recommended industry rates of application so sufficient water is applied to maintain turf and garden beds to an acceptable standard.
Irrigation programs are calculated to ensure the optimum volume of water is applied per month within the percentage allocated for that month. Unless the rain is significant, it is not usually enough to meet the monthly application requirements and irrigation is therefore still required. As most rain events are unpredictable in the volume of actual millimetres of water on the ground, reticulation maintainers typically do not alter irrigation programs for the chance of rain, but make assessments and alter programs after the rain has fallen. Many of the City’s irrigated sites are fitted with rain sensors which will turn off the irrigation if the rain is of sufficient volume.
We closely monitor our usage monthly through water meters fitted to each of our bores, and report annually to the Department of Water on that usage (which must be within the allocated budget).
Why are the sprinklers operating in winter?
From time to time residents may see sprinklers in parks and street gardens running during winter. It would be reasonable for residents to assume we are not abiding with the Department of Water's winter sprinkler bans and are wasting water.
Irrigation systems under the care and control of the City have been programmed to automatically activate once every two weeks during the winter period for maintenance purposes. In circumstances where industrial-grade irrigation systems are left dormant during winter, it is common for them to malfunction when activated at the beginning of summer due to a build-up of scale and algae in the pumps, pipes, valves and sprinklers. The resultant loss of grass and shrubs requires even more water to re-establish them, compared with the water used to maintain the systems during winter.
To ensure that each system is running for the shortest possible time to achieve the maintenance objective, each group of sprinklers has been set to run for a period of time no greater than that required for their control valve to fully open and then immediately begin to close down. This flushing cycle usually takes no longer than two to five minutes.
By undertaking winter maintenance we ensure that our 200 irrigation systems complete with 1920 control valves and approximately 20,000 individual sprinklers are functioning at the beginning of each summer period. In so doing, the aesthetic quality of grass and garden areas is not compromised and we save water in the long run.