In Aotearoa New Zealand, 20 percent of drinking water is lost to leakage, 90 percent of the piping network is unable to provide accurate data on its condition and 50 percent of water use is unmetered, meaning we have extremely limited knowledge on water use across the country.
Te Whare Wānanga o Waitaha | University of Canterbury (UC) Civil and Natural Resources Senior Lecturer Dr Derek Li, the principal investigator of this Marsden grant, says that unlike the electricity industry, where usage can be tracked by customers, in urban settings the general consumer has little understanding of water usage – unless they are paying for it. “When we don’t know how we use water, we don’t care, because we don’t have feedback about that information.”
The Marsden Fast Start grant will allow Dr Li and Professor Pedro Lee to continue previous research from the first round of Marsden funding they received for remote sensing technology; exploring a discovery from the initial research where the ability to track pressure signals when taps were turned on or off was uncovered. The technology being developed will continuously and simultaneously extract water usage and pipeline conditions, simply by listening to background pressure noise in the network.
This means a detailed picture can be formed of household water use and the percentages that are used from the garden sprinklers to showers and toilets across New Zealand. The information received will inform water conservation strategies and provide accurate asset condition information.
Dr Li says water loss is a global issue. “There are two contributions to this; the first is broken infrastructure – these pipelines [in New Zealand] were deployed 50-70 years ago and they’re quite old – and the second is the excessive usage of water.”
The technology would also provide the ability to monitor water use during times of drought, ensuring usage is optimised.
Globally, this technology could be applied in countries with limited access to clean water to reduce unnecessary water loss.
Dr Li and the team has been using existing piping networks across UC and the wider Waitaha Canterbury region to test the technology. He successfully deployed it in the Waimakariri District, finding two pipes in poor condition which burst within a few weeks of being identified.
“These algorithms will be trained and tested using a database established through comprehensive experiments, supported by the state-of-the-art laboratory and real-world water supply networks at the University of Canterbury campus.”
The technology will provide detailed data on how New Zealand uses its water, and facilitate future research on water conservation strategies, as well as providing accurate asset condition information to optimise the rehabilitation of ageing water pipeline networks.
“The next stage of funding would be improving the device. If we are successful in our research, then we would look to industry to help us find a sustainable system that can sit in the [water] system for a long time.”