Henry County Water Authority in Georgia, USA, had been relying on acoustic leak detection for eleven years, working with a dedicated leak detection company (Matchpoint) that uses noise loggers and other acoustic listening devices to find leaks.
However, these traditional ground-based methods of monitoring Henry County’s extensive water catchments and infrastructure have their limitations.
Not only are these methods costly, time-consuming and resource-heavy, but they’re difficult to deploy over large and sometimes remote areas. This means that data is updated infrequently, and the overall approach is reactive, responding to failure after it happens rather than preventing leaks before they occur. This in turn can make it difficult to meet stringent water quality standards and monitoring regulations.
The impact of a leak is enormous, involving parts of the water supply being shut off, time and money being spent repairing not just the leak but the road and other infrastructure affected by it, and dealing with the resulting insurance claims and regulatory fines. What’s more, with the completion of Level 1 water loss audits mandatory each year, it’s in Henry County’s interests to improve on its current water loss rate of around 10%.
Rezatec stepped in to provide a complementary service to Henry County’s existing acoustic leak detection work.
While the thinking behind the project was initially simply to reduce leaks, it became clear during the project that Earth Observation data could add most value by predicting risk, identifying the likeliest points at which Henry County’s assets could fail.
This would allow Henry County and their leak detection agency to deploy their ground-based devices more effectively, as well as giving them the intelligence they needed to plan infrastructure investment and repairs to prevent future leaks.
The project, which is ongoing, has had two main phases so far:
PHASE 1: Pipeline leak detection
The project initially looked for indicators of asset failure in the potable water supply, looking out for telltale signs of leaks, such as vegetation vigor and terrain motion.
It also assessed topological and hydrological data and reviewed historic leak data and pipeline information.
PHASE 2: Infrastructure risk management
Risk assessments were then identified as a more pressing concern, given their ability to identify high-risk areas of the Henry County infrastructure before leaks occurred.
These start by looking at key causes of pipeline failure, including :
- Terrain motion
- Vegetation intrusion – particularly relevant to the more vulnerable sewer network, which comprises unpressurised clay pipes
- Disturbances as a result of human activity
- Pipeline attributes – such as age, material, and diameter (larger pipes being most at risk)
- Historic failure events – including location, volume, and the nature of the failure
Statistical analysis then integrates these attributes into a model to classify pipeline segments based on the relative risk of future incidents. Each section of pipe is given a cumulative pipeline risk, with overlapping reporting areas created along the pipeline network and a combined pipeline risk calculated from intersecting pipelines. Once high-risk areas are identified, acoustic monitors can be strategically deployed to monitor them.
In time, the aim is to create automated alerts to newly identified ‘hotspots’, visualizing the information through a user-friendly portal with data that can be conveniently exported into other GIS and workflow tools.
Key Benefits and Outcomes
While the project is ongoing, the more focused approach already enabled by Rezatec’s infrastructure risk assessments has big implications for the effectiveness with which Henry County can manage its catchments and infrastructure.
The Rezatec project is giving Henry County the intelligence needed to be more proactive, mitigating risk by preventing leaks before they occur and cause major disruption.
By allowing better deployment of ground-based leak detection resources, the Earth Observation data should also help reduce the cost of monitoring such an extensive pipeline network. And, by sharing the results with the wider industry, it’s hoped that similar projects will help other utility companies to benefit from this technology in due course.
“Matchpoint and Rezatec have helped aid our efforts in nonrevenue water management by adding another tool to our tool bag. The Rezatec satellite asset management survey has helped verify and improve our current leak detection processes.” – Brock Biles, Henry County Water and Sewerage Authority