Water loss management is one of the most important issues facing water suppliers around the world. The Sustainable Development Goals have made poverty alleviation and access to safe drinking water a political priority. Targets on providing safe drinking water as a basic human right aim to ensure everyone can access a safe water supply. Unfortunately, the reality is that many of the most vulnerable around the globe still struggle to find a reliable supply of safe drinking water.
Water shortages are being experienced in virtually every corner of the globe. The problems are usually attributed to climate change, natural droughts, poor infrastructure maintenance, population growth, lack of funding, lack of experienced management – the list is endless.
In reality, there is rarely one single factor causing the problem and it is often a combination of different factors that lead to water shortages. As populations grow, demand on water resources increases, which under natural flood and drought events will already result in periods of surplus and periods of shortage.
Climate change is itself not solely responsible for floods and droughts, neatly summarised by Christiana Fugueres, Executive Director of the UNFCCC, at the COP21 Summit in Paris. She stated that, “Natural disasters are not caused by climate change but the intensity and frequency of such disasters are exacerbated by climate change”. In other words, expect droughts and floods to become more severe and more frequent in future.
Efficient use of water resources is critical
Recent drought events, such as Australia’s east coast, Brazil’s industrial heartland of Sao Paulo and across agriculturally rich California, resulted in wide-scale water shortages. Even without the aggravating influence of climate change, the impacts of drought on water supplies in many areas have been increasing due to population growth and land use change.
This makes it critical that the available water is used efficiently and that water losses are reduced.
Every town and city has its own unique combination of problems. Some cities have high water pressures; others have no water pressure and may experience intermittent supply. Some cities have ample financial resources to repair leaks within hours; others have no funds to buy clamps and leaks may run for months, if not years before they are repaired. Some cities deal with pipes that are over 100 years old; others have new systems only 10 or 20 years old. These present unique challenges for water professionals around the world.
The IWA Water Loss Specialist Group works towards solving these challenges though the combined expertise of its members, who have experience ranging from some of the most sophisticated water networks in the world, to some of the poorest systems that require immediate assistance.
Over the past 20 years the group has documented a range of issues and solutions, in an attempt to help water supply managers to reduce losses and improve water use efficiency. Some of the key issues include:
- Standard IWA Water Balance: The IWA has developed and encourages the use of a standard water balance as the first step in addressing water losses.
- Burst and Background Estimate Methodology: The IWA has taken the initial recommendations from the UK water industry involving burst and background losses, to understand and analyse leakage in water supply systems, and creating the ‘BABE Methodology’, a virtual “science” on the analysis and management of leakage.
- Commercial and Physical Losses: The IWA recommends that commercial and physical losses are identified and, if possible, quantified in a standard approach. Both forms of losses are important and require different approaches to reduce them.
- Pressure Management: The IWA stresses the importance of managing water pressures in supply systems, highlighting the fact that pressure drives leakage. The concept of fixed and variable area leaks helps explain why leakage from certain pipe materials (asbestos cement, plastic) is highly sensitive to pressure, while leakage from metal pipes tends to be less sensitive to pressure.
- Sectorising: Large areas should be split into smaller areas to help identify high leakage zones. Original recommendations of around 2000 connections to a zone have been relaxed and larger zones are now often considered to be appropriate.
- Minimum Night Flow Monitoring and Analysis: Analysing the minimum night flows into an area have long been the backbone of any water loss management programme. Despite advances in computer and communication technologies and leak detection methods, the monitoring of night flows remains one of the most significant water loss management approaches.
Tackling water loss is one of the critical solutions that can enable communities to better adapt to climate change and variability, amongst other water challenges. As a community of water professionals we must drive the agenda that enables this to happen, so that the ambitions of the Sustainable Development Goals and the human right to water can be achieved.