Proper pressure management in rural New South Wales

Davies installed a pressure logger to verify her modelling work.

Having the proper pressure levels in a water network is vital for water loss management. Ashlynn Davies has been studying this and has been rewarded for her project.

When people think about regional water utilities, they rarely think about the issues of leaks and high pressure. However, these can be some of the biggest problems facing regional water utilities with smaller connection bases.

Improving the efficiency of water networks is essential for these regulated businesses, and Ashlynn Davies from the University of Sydney studied it at the regional level. Her paper, Improving Water Network Efficiency in Regional New South Wales: Leakage and Energy Use Reduction Through Pressure Management, was nominated as a finalist in the New South Wales branch of the Australian Water Association (AWA) Student Water Prize.

“I had a less conventional path into the water industry,” said Davies. “I was fortunate to receive a Major Industrial Project Placement Scheme Scholarship through the University of Sydney’s School of Chemical and Biomolecular Engineering.”

This program supports outstanding senior students completing a high-level industrial project during a six-month employment placement. Davies was placed with the Central New South Wales Joint Organisation (CNSWJO), which represents 11 central NSW local government authorities (LGAs). While her project specifically involved collaborating with Parkes, Orange and Bathurst councils, her findings were aimed at having wider applicability across the region.

“The project required me to look at water loss from an energy perspective,” she said. “It was an expansion of the previous year’s project, which had just looked at water loss. Once I had explored water losses and associated energy losses from each council’s network, I saw an opportunity to expand my project into exploring pressure management to address these inefficiencies.”

Water leakage

The reality is that there are no water utilities of any size that do not have any water leaks anywhere in their systems. The difference between large cities and smaller regional towns can be stark.

“In regional areas, many towns were established over 100 years ago,” Davies said. “Their establishment led to the origins of its water networks. Those networks grew as the population of the towns grew. The challenge is that there is a lot of ageing infrastructure in these areas and limited funding for large-scale infrastructure renewal projects.”

That drove Davies’ motivation for pursuing pressure management options. If there is no money for significant renewal works, what can be done to save water, energy, and money? It’s all about utilising the councils’ resources as effectively as possible.

“Water is a vital resource for regional communities,” she said. “In times of drought, the local population is extremely aware of water scarcity. As we face growing uncertainty around water security in the future, it is increasingly important for these councils to study their systems and understand where they can be improved.”

What Davies did

There were four stages to Davies’ research, with the first three working towards the final stage of her research.

“The first thing I did was quantify the water losses,” she said. “Typically, that uses the International Water Association (IWA) water balance method that looks at the entire system. However, I quickly decided it wouldn’t provide the granularity I needed. Instead, I wanted to quantify water and energy losses from each specific network zone rather than just the network as a whole.”

She had to combine various data sets to develop a water balance in each network zone to achieve this. That included billing, geographic information systems (GIS), and Supervisory Control and Data Acquisition (SCADA) systems. The GIS had a layer that showed what areas were fed by what reservoirs. Pairing this information with the billing data allowed her to calculate the total consumption in each zone. Meanwhile, the SCADA system provided the bulk water meter data to estimate the total water delivered to each zone.

“Essentially, I did a water balance across every specific network zone that I could,” said Davies. “That allowed me to pinpoint how much water was lost from each network zone. Surprisingly, there were immediate actions I could identify at this first stage of my research.”

As part of this stage, she found significant water loss in Lucknow, not far from Orange. A repairman was sent out, who found a leak on the line between Lucknow and Orange and fixed it.

“The second stage saw me develop a methodology to calculate the embedded energy lost from water for each specific zone. Each time water is pumped or treated, its embedded energy increases, resulting in greater energy losses when that water is ultimately lost from the network,” Davies said. “This allowed me to determine which zones are the most energy-intensive and contribute most to the networks’ overall inefficiency.”

The third stage saw Davies use InfoWorks Pro, a hydraulic modelling software. She used this to perform an energy balance on each network zone to quantify which areas delivered the most excess pressure to the customers.

The final stage of the research

The fourth and final stage saw Davies combine the first three stages of her research to determine what network segments needed prioritising for pressure management and other efficiency improvements.

“I modelled 12 different actions that could be taken across the three councils I worked with,” she said. “According to my calculations, implementing these would result in a water loss reduction of 184 megalitres annually with an annual retail value of $423,000 and energy savings of 366,000 kilowatt-hours per year.”

Davies specifically recommended actions where little investment is necessary. The largest investment would be the purchase of a pressure relief valve (PRV). However, more than half of the actions required simply changing the configuration of the zones to ensure areas are not supplied by reservoirs at a higher elevation than necessary.

“That meant opening a couple of zone valves and closing a couple of others, as there was often an adjacent reservoir capable of supply the ideal pressure,” Davies said. “Those were the actions that were most surprising to me. It was exciting to find ways for the councils to use the infrastructure already in place to improve water loss and resulting energy loss.”

“Similar actions can likely be found in the networks of other local water utilities across the region, with the methodologies I developed through my project a great place to start.”

Award winner and nominee

Davies has been nominated for the NSW AWA Student Water Prize and won the best undergraduate thesis from the University of Sydney’s School of Chemical and Biomolecular Engineering.

“I’m just excited that my work was able to lead to real actionable benefits for the three councils, with the potential to help many other local water utilities. It’s a nomination for a lot of people, for whom a project of this scale otherwise could not happen.”

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