Effectively dealing with water leakage in our network is a compelling challenge, and last year we managed to beat our Ofwat target. However, we know that we can't be complacent - and we're looking to technical innovation to help us.
For our leakage managers, the big problems are the leaks and bursts that never make it to the surface or, if they do, only generate local damp patches or flow along the gutter to the nearest drain. Cumulatively, we lose a lot of water this way.
What are we doing about it?
The water industry has used pressure-reducing valves to reduce leakage and acoustic 'listening' equipment to try and find the leaks in the network, but neither solution has been completely effective. For the last couple of years our hydraulics engineers and network modellers have been working with Bentley Systems to come up with new ways to beat leakage. One of the results is a computer application that predicts where leakage hotspots are likely to be.
The new application makes use of all the mathematical models of our distribution networks, together with recorded pressure and flow data. Mathematicians have known about genetic algorithm methods for many years. These methods are like a structured seek-and-find approach for solving numerical problems. Now, with the advent of powerful computers, these techniques have come of age - and we can use them to our advantage to find leakage hotspots.
At night, we can measure the mains flow into a closed area and estimate the leakage taking place, but we can't be sure just where the leakage is occurring in that area. However, a telltale sign of the prevailing flow pattern in the network are the local pressures that exist across it. By using genetic algorithms, we've been able to assign the leakage to a specific area so that the pressures predicted by the computer model agree closely with those measured on the real system.
Finding leaks
As a result, our people have been able to find leaks that they might otherwise not have done. It's still early days for this new technology and there are improvements that can be made to it. But we're pleased to say that the new methods are being introduced as a 'business as usual' task within our water network modelling team.
The industry seems to agree it's a good idea too - together with Bentley Systems, our leakage hotspot application inventors, we won the 2008 International Water Association's European Honour Award for Project Innovation.