INTRODUCTION
Mer Island (also known as Murray Island), is a small island of volcanic origin, characterised by red fertile soil and dense vegetation. The island has a population of approximately 450 people and is situated within the eastern cluster of the Torres Strait island archipelago, within sight of the Great Barrier Reef in Queensland. The island is one of fourteen serviced by Torres Strait Island Regional Council (TSIRC).
THE CHALLENGE
The conditions faced on Mer Island are somewhat unique, including remote location, water storage, water losses, and economic challenges. As a remote community, Mer Island has experienced ongoing and broad issues associated with growth in the region, resulting in lower service provision standards compared to more densely populated regions. This has led to a legacy of sub standard water supply over the last 20 years and severe water restrictions with reliance on desalinated water proving ineffective and cost prohibitive.
Additionally, the water supply on Mer Island was overwhelmed by significant water losses leading to water security challenges. This resulted in the communities access to potable water restricted to the hours of 7-8:30am, 12-1pm, 4- 7:30pm (totalling 6 hours of supply per day). The issues however were not just associated with the ongoing water losses, there was limited access to accurate infrastructure drawings and high uncertainty regarding the condition of the water mains. Without a clear idea of where infrastructure was located and operating under the assumption that the water mains were of poor condition when commissioned, issues were largely unknown.
THE ASSESSMENT
TSIRC approached Assetlife Alliance to demonstrate how adopting a demand focused strategy, using the latest technologies could provide sustainable and reliable potable water supply with significant cost reductions. This consisted of providing specialised solutions including acoustic sound file analysis using Artificial Intelligence (AI) analysis, high performance acoustic hydrophones leak detection identification, equipment and training, Including advanced pressure control systems, the very latest low head loss and low maintenance pressure control valves with the operational pressures controlled in a closed loop environment.
Potable water for the island is predominately captured during the wet season (December to April), with rainfall stored within a 20ML covered lagoon. With minimal rainfall during the middle of the year, water demand/losses continuously drained the storage levels. The water supply is supplemented by three permanent reverse osmosis (RO) units that can each produce 70kL/day. Additional storage prior to distribution include two elevated water reservoirs which are located close to two separate community areas including a total of 137 connections.
THE SOLUTION
With the water leaks assumed to be as high as 6L/s, initial leak detection investigations with acoustic sensors were used to pinpoint locations of the leaks and artificial intelligence used analyse the data. Next came the installation of smart water meters to increase visibility of where supply was being used within the community. Pressure control systems and valves were installed to critical locations to address high pressures and fluctuations in the distribution network while a new bulk flow meter monitored network supply. Assetlife Alliance training of Council’s engineering and technical officers allows for targeted field operations to detect and repair issues as they are identified.
By implementing an intensive demand management strategy incorporating smart technologies, artificial intelligence analysis and implementing calm water network strategies, water demand on Mer Island has been brought back to a sustainable position providing a positive outcome for the community and TSIRC Council. Water restrictions have now been lifted and potable water is accessible 24/7, leak levels are now down to 0.5 – 0.7 L/s, mains pressure is reduced 3-fold, from 50m to 15m head and water levels in the storage lagoon are the highest recorded since it was first commissioned over 20 years ago. As the lagoon has reached capacity, the RO units have been shut down temporarily which will allow for much needed maintenance.
Assetlife Alliance is working with TSIRC to identify and further improve opportunities to ensure an efficient and sustainable water network for Mer Island including:
- DMA water balancing and intervention triggers for leak detection
- Further pressure management optimization opportunities
- Hardware and software support.
Adopting this approach for Mer Island showcases the advantages in addressing critical supply issues
using an intensive Demand Management Strategy.
