Christchurch City Council manages the the water supply network for Rawhiti, providing drinking water, sewage and recycled services to its customers. Rawhiti is located east of central Christchurch, running from Wainoni in the west to New Brighton in the east. The area incorporates over 11,000 connections which are predominantly residential with a small percentage of commercial business’s.
Christchurch City Council required an understanding of the latest network information and performance changes to provide up-to-date knowledge and understanding of vulnerabilities within the Rawhiti water network. They required a long term solution to address these challenges with a focus on critical assets and acoustic/transient network profiling which would allow a proactive response to identified issues. This would include continuous real time monitoring of pressure transients and leak detection with a view to a reduction of non-revenue (NRW) losses.
Working collaboratively we were able to establish asset criticality with likelihood/consequence of failure and correlate with customer importance to identify challenges and prioritise investment or renewal strategies.
As part of their Smart Water Network Programme, Christchurch City Council engaged Detection Services to provide innovative solutions using state of the art technologies to enhance operability and performance for the Rawhiti water network.
The Detection Services initial investigation included analysis of existing Christchurch City Council network data such as network density, connectivity, mains by age, materials, assets deemed critical, and break frequency history etc. This provided a unique overview of the network, determined high risk locations and supported an accurate and targeted sensor deployment program to cover the water supply zone.
To support the investigation, continued data analysis provided clear and valuable insights into potential issues within the Rawhiti network. This data highlighted the at risk areas in the water supply zone including analysis of ‘criticality and consequence of failure’ and a calculated leakage index to determine a failure prediction model (FPM). It also identified monitoring locations that would provide optimal coverage of the zone and support those high risk areas within the network.
Detection Services provided a sophisticated hardware and software solution which provided insights into the network and its characteristics using advanced transient analytics such as Cumulative Pressure Induced Stress (CPISTM). This provided insights into the anomalous behaviour correlated to burst frequency, pressure cycle characterisation etc. and provided a clear visualised analytic metric of stress in the network. The Detection Services solution allowed for field services and analysis to target areas of concern rather than just a ‘blanket approach’ to align with Council’s objectives and budget.
Within the Rawhiti zone, asbestos cement mains are the single largest percentage of all pipe materials in this zone, with approximately 10% of the network have pipelines between 200 and 300mm in diameter and considered a high risk critical asset. Twenty (20) assets were identified for transient monitoring (fire hydrants) with installation of Inflomatix pressure transient sensors. Two hundred (200) assets identified for acoustic monitoring with installation of HWM PermaNET sensors for leak detection.
Data combined with field services provided for a greater focus on the most productive acoustic noise logger targeted locations, and permanent transient monitoring stations. Analysis of data received in parallel with the FIDO AITM (artificial Intelligence) platform was used to to enable pro-active condition assessment to optimise the network. This cost effective approach allows for scalable and expandable solutions for future system integrations.
The approach adopted for Christchurch City Council and the Rawhiti network showcases
how Detection Services strategies and technologies allow customers to maximise the value
of their assets and achieve long term sustainable solutions.