£30m is a lot of money. For 100,000 listening devices. That cover just 20% of the network. Will they deliver the leakage reduction anticipated?
The UK water company deploying them claims that the project has already saved up to 5 million litres of water a day.
Fixing more leaks and faster will certainly reduce leakage. But only in the short-term. Usually around 1 year. Then leakage goes back to pre-existing levels. Why?
Water networks are old and getting older. Pipe replacement rates are less than 1%. If you fix a leak, then you strengthen that point in the network. Absolute levels of pressure and fluctations in pressure levels including transients will then erode the rest of the network at a faster rate. Before long, there will be a leak somewhere else. And you’re back to square one.
Prof Speight, an expert in drinking water quality at the University of Sheffield, thinks that water companies need to consider a very large-scale replacement of pipe.
If replacing a main costs £500,000 per kilometre, £30m would replace just 60 km. That’s just 0.15% of the water network in question. Water companies won’t be considering that for very long in addition to what they already spend.
A better, more cost-effective plan would surely be to spend less than £10m to reduce existing leakage and reduce stress on the network:
Use Advanced Pressure Management (around £5m for the water company in question with around 3,000 pressure managed areas) to
Reduce pressures to minimum viable levels
Ensure pressure changes are achieved without damage to the network
Identify and eradicate transients from the network (around £3m for the water company in question with 5 loggers in each pressure managed area and the software service required)