Every single day in the UK, over 3 billion litres of perfectly good clean water is being wasted. That’s enough to fill 1,200 Olympic sized swimming pools. It’s estimated that this equates to roughly 25% of the UK’s daily water consumption.
Despite the stories we may tell our children, the majority of this wastage comes from leakages from pipes within water networks, and not from leaving the tap on whilst brushing our teeth or having a bath. Although every drop we can save does of course make a monumental difference.
So how is this happening? And more importantly, what can water companies do to prevent this? In this feature, we’ll explore all these questions in an effort to understand the complexities of our water networks.
What exactly is a leakage and how is it classified?
When referring to leaked water, we are talking about any treated water (i.e. cleaned) that is lost from the water network’s distribution systems and supply pipe losses from consumers’ pipes.
Essentially it is any treated water that a water company is unable to account for as having been used by someone. This can be broken down into two sources:
- ‘True’ or ‘Real’ losses, includes any water that is lost from a network’s pipes into the ground. For the average water company, a pipe network consists of mains (which move water around their supply area), communication pipes (which supply water to a property from the main) and other fittings, such as stop taps and valves, which allow them to control the flow of water.
- ‘Apparent’ losses refers to any water use of which a water company isn’t aware, such as illegal tapping, higher-than-estimated use by households and businesses that don’t have a meter, inaccurate metering and any data-handling errors.
What causes these leaks?
There are many factors that affect ‘true’ leakage, but the main ones are:
- Operational strategies, i.e. pressure management
- Network characteristics, i.e. length of mains
- Asset condition, i.e. age or natural wear and tear caused by pipe corrosion, ground movement, repeated stresses such as weight of traffic on roads above
- Changes in season and weather, i.e. in colder winter months it’s common to see an increase in pipes shrinking, causing disruption to the joints and increasing leakage. On the flip side, in hotter summer months, long dry periods can cause the earth to shrink, causing further movement of the pipes it usually supports and subsequent bursts.
- Customer base composition, i.e. rural or urban
Who estimates the amount of this wasted water?
Each water company is responsible for estimating their own water leakage and reporting it to Ofwat. They do this by comparing the measured volume of water that they recorded as being entered into supply, against the volume they estimate is being used. The difference between these two values is then recorded as leakage. Nearly all companies measure leakage in millions of litres per day (Ml/d).
What are the benefits of reducing water leakages and wastage?
Ofwat has set water companies ‘stretching performance commitments’ to reduce leakage over the period between 2020-25. By achieving these commitments, the sector aims to cut leakage by 16% by 2025. This reduction would save enough water to meet the needs of every person living in Cardiff, Birmingham, Leeds, Bristol, Sheffield and Liverpool combined.
Rather than looking at the negative consequences of water leakages, we prefer to look at the wider positive impact that prevention and reduction can have:
- Reduced abstraction and therefore environmental improvement
- Increase in the planet’s drinkable water resources
- Reduced operating costs for water networks
- Reduced fines for water networks
- Increased reliability of water supplies
- Deferment of capital expenditure on water resources and supply schemes
- Improvement in the public’s opinion of water companies
- Reduced energy and chemicals for treatment and pumping which will reduce carbon emissions
- Reduced infrastructure damage, i.e. weakened road foundations
- Reduced flow and headloss, facilitating pressure to be stabilised and optimised
What measures can be taken to mitigate this wastage?
One of the main recommendations highlighted by Ofwat is for water networks to adopt more innovative approaches to deliver these reductions efficiently. When utilised properly, technology and data should successfully aid and enable across these four core areas:
Identify anomalous behaviour in a network before they lead to performance issues and mitigate the causes to achieve ‘calm network’ operation
The ability to understand and have awareness of weaknesses in a network, allowing action to be taken immediately
The ability to identify and locate weaknesses, enabling specific action to be taken without disrupting huge parts of a network
Tailored outcomes and actionable data in order to solve the problems that have been identified
There are many factors at play when looking to achieve a calmer network and reduce water leakage.
Utilising arboricity™, our near realtime hydraulic network modelling service, allows higher level automated analytical services to be brought online which are cognisant of the hydraulics of the network and therefore not ignored, increasing confidence in operational decision making and providing actionable insights.
High frequency technology InflowSys™, is also able to capture and localise significant pressure events within a network using leading edge analytics.