Having explored other methods, including aerial surveys, Hunter Water signed a three-year subscription for Rezatec’s Dam Monitoring product, leveraging geospatial analytics to track structural and environmental changes at Grahamstown Dam. This was offered in collaboration with local partners Detection Services, who specialize in supporting multi-discipline technologies for the water and wastewater industries.
Rezatec’s Dam Monitoring solution uses Synthetic Aperture Radar (SAR) to track ground motion and multispectral data to study vegetation vigour and moisture, both of which are indicators for potential dam failure.
One of the unique features of this technology is the ability to call upon a library of historic data to ‘look back in time’ and establish a baseline for what is normal behaviour for any given dam.
In the case of Hunter Water, Rezatec analysed three years of historic SAR and two years of multispectral data to provide a retrospective analysis. This first step is critical to identifying anomalies, or observations outside ‘normal’ thresholds, by establishing a baseline trend of what is ‘normal’ and what isn’t.
The retrospective analysis on Grahamstown Dam spanned a period of time where, unbeknown to Rezatec, several pieces of major work had been completed. Firstly, pipes had been installed through the crest of the dam where, for a short time, there
was an open excavation. Secondly, top soil had been applied to the embankment to generate vegetation growth.
Using this baseline trend data, Rezatec and Hunter Water agreed the normal behaviour threshold. This enables the analytics to identify anomalous behaviour and notify Hunter Water’s team where to direct their resources.