Australian state-owned corporation Hunter Water is working alongside partner Detection Services to expand Rezatec’s Dam Monitoring service across Chichester Dam in New South Wales, with the service already in use at the corporation’s Grahamstown Dam.

“Using Rezatec’s Dam Monitoring technology aligns perfectly with our strategic objectives to increase digital services and improve the delivery and adoption of technology. Dam Monitoring enables a significant increase in the frequency and accuracy of monitoring for both Chichester Dam and Grahamstown Dam,” commented Daniel Turnbull, Dam Safety Engineer at Hunter Water.

Supplying nearly 35% of Hunter Water’s potable drinking water supply, Chichester Dam is a 44m-high mass gravity concrete dam, curved in plan, with a 262m crest length and a centrally located spillway. At nearly 100 years old, the dam was originally constructed between 1918 and 1926, with the first water supplied in 1923. The dam has been upgraded throughout its life-span, with the most significant works completed in the early 1980’s, when an enlarged spillway, now 112m in length, was constructed and 93 post-tensioned anchors were installed in the dam wall to reduce the risk of overturning.

“Due to the steep, heavily vegetated terrain in the vicinity of Chichester Dam, deploying traditional survey techniques are difficult, time consuming and costly,” added Turnball. “Traditional surveys are currently undertaken for the site on a two-yearly basis in accordance with regulations.”

To enhance public safety and understand Chichester Dam’s behaviour, Rezatec’s Geospatial AI initially interprets three years of historic satellite data to create a retrospective analysis. This first step establishes a baseline trend of what is ‘normal’ and what isn’t.

Turnball and the team at Hunter Water then receive monthly updates, using data collected at six-to-twelve-day intervals, to flag and locate any arising issues, down to a few millimetres of displacement. In addition to monitoring precise structural movements, the satellite data analyses vegetation moisture and vigour to pick up indicators of seepage.