Using fibre optics to detect water leaks

In South Africa‚ more than a third of the country's water‚ an average of 37 percent‚ is lost through leaks. In Pretoria alone‚ a shocking 75 million cubic metres of water is lost to leaks every year.

So‚ what if it was possible to detect leaks well in advance‚ and long before such massive water losses are incurred?

A team of researchers under the direction of Professor Schalk Jacobsz at the University of Pretoria is currently investigating the use of fibre optic instrumentation for the detection of leaks in pipelines.

The research project‚ which was started in April 2017‚ is funded by the South African Water Research Commission.

Speaking during the Water Institute of South Africa’s WISA2018 conference‚ currently on in Cape Town‚ Jacobsz detailed the findings of the research project so far.

Jacobsz said the first phase of the project is nearly complete. It investigated leak detection using Fibre Bragg Gratings - short segments of optical fibre that reflect particular wavelengths of light and transmit all others. These were used to measure strains and temperature on pipelines and in the ground adjacent to pipelines. The next phase of the research will focus on distributed strain and temperature sensing.

“The problem with leaking pipes is that often you have lost a lot of water before the leaking water surfaces. We know we can find leaks by burying a fibre optic cable into a pipe trench with any new pipe or we can retro fit it by burying the cable above an existing pipe‚ all with a view to detecting leaks in pipes. We are still researching aspects of that‚” Jacobsz said.

“What we want to do is feed the cables into a leakage detection centre where we would have somebody monitoring those pipes. If there is a deviation‚ it is then possible to send someone out to fix the leak. This early detection means we do not lose massive volumes of water.”

Jacobsz said his team were currently researching the technology and indications were that it was showing great promise as a highly effective leakage detection system.

“I hope that‚ through this research‚ we will be able to implement workable leakage systems‚ and save the country an enormous amount of water and money and thereby ensure that more water is available to disadvantaged communities‚” he said.