All quiet on the eastern front, but not so in the west…

16 November 2023

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Dam integrity project background

Back in 2021, HydroTerra was engaged to conduct an investigation of the eastern section of a large dam wall.  The investigation allowed us to evaluate the integrity of the dam wall and provide the client with a detailed assessment.  Later down the track, the client discovered seepage concerns on the western section of the dam, prompting them to re-engage HydroTerra to investigate.

Project circuit wire and measurement points

Challenges

In December 2022, HydroTerra initiated the project’s next phase, however there were obstacles to progressing the project.  Local wildlife had been chewing through the circuit wire originally laid down for the assessment. The predicament forced us to temporarily pause and rethink our strategies.

Collaborative approach

It isn’t easy to understand what is happening with the water beneath our feet. Willowstick is a geophysical technology company that provides quick and non-intrusive equipment that can identify, map and model preferential groundwater connection paths.  A Willowstick investigation typically identifies specific areas that warrant further investigation while reducing the number of additional wells that need to be installed.  The early application of a Willowstick investigation saves time and money by eliminating unproductive remediation efforts.

HydroTerra worked with Willowstick and the client to devise ways to safeguard the circuit wire from further damage by wildlife, we had to ensure the wire was free from damage and would support our investigations. Our collaborative efforts resulted in several key strategies:

  • Deploying the wire in a single day with the help of 4WDs and client-provided subcontractors
  • Timing the fieldwork during a cooler season to minimize mammal activity
  • Routing the wire along fence lines, avoiding forested areas
  • Increasing field personnel to maximise the use of the three Willowstick instruments

 

Example dam survey results

Project Execution

Using the revised strategies, HydroTerra remobilised in October 2023, and Mitchell Green, from Willowstick, joined us in the field. The land portion of the wire was successfully laid out in a single afternoon, and the water portion followed the next morning. What’s more, all survey points on land and water were captured in a single day, thanks to the exceptional teamwork of the project team.

 

If you are interested to see how HydroTerra can apply the Willowstick technology to your next project, head to our website to see the range of products. Willowstick Products

Willowstick are constantly improving and developing new technologies.  Their latest product is Mirco Seismic Resonance (MSR).  You can find out more about that in the next article.

Micro Seismic Resonance by Willowstick