This blog was written by Vanessa Speight, Senior Research Fellow in Integrated Water Systems. Vanessa is also Managing Director of TWENTY65, a research programme focused on interdisciplinary teams working across the water cycle to develop flexible and synergistic solutions tailored to meet changing societal needs and achieve positive impact on health, environment, economy and society.
This year on World Water Day, I would like to give thanks to the hard working pipes that deliver fresh water to my home and work, all day, every day. Many of them are old, past their prime, abused and forgotten and unappreciated. But they make it possible for me to live my daily life without ever stopping to think about water: how I will get it, whether it’s clean and safe, and whether it will be available at the next place I stop.
In many cities in the world, the pipes are under attack. In developed countries, decades of neglect have resulted in high leakage rates. In England and Wales alone according to Ofwat data on water companies performance 2014-2015, 3 130 megalitres of treated water is lost every day through leaks, which equates to supply for 20.4 million people at current consumption rates. In developing countries, where statistics are available, the problem is much worse. Asian cities are estimated to leak a staggering 60 000 megalitres per day, enough to supply 230 million people at typical consumption rates, while simultaneously struggling to find new sources of water and expand piped water service.
The leaking pipes lead into an even more dangerous situation. As leakage grows, many water systems cannot maintain pressure and water supply becomes intermittent. There is mounting evidence that the cycles of depressurisation and repressurisation stress the pipes beyond their limits, resulting in more and larger leaks. The higher leakage stresses the supply even further, forcing more and more infrequent supply. And on it goes. After 3 years of intermittent supply in Cyprus brought on by drought, the number of pipe breaks had tripled with an increase in leakage of 9%. The downward spiral of intermittent supply is a key global issue, with recent estimates suggesting that as many as 679 million people in 59 countries experiencing supply outages on a regular basis.
Our overworked pipes are also responsible for water quality degradation. Water distribution system deficiencies represent the largest category of causes of waterborne disease outbreaks in the US. In intermittent systems, there is evidence of higher bacteriological contamination levels, although this remains an area with little research and data collection.
As we move toward fulfilling the UN Sustainable Development Goals, especially clean water and sanitation (SDG 6), we need to remember the pipes. In many cases, it is assumed that building pipes to connect new users to centralised is the end of the problem water services. But without proper design, operation, maintenance and governance of the pipe networks, those water services will not be reliable or safe. In a recent study, my co-authors and I found that only one system out of 52 major metropolitan water networks studied in South Africa meets the requirements for minimum pressure at all locations (building upon previous work).
Yet the problems of intermittent supply are not widely acknowledged and even less well understood. Clearly, addressing the pipe problems could improve millions of lives so we will keep working to find innovative, low-cost solutions for leakage testing, maintenance of water quality, and network operation. Those of us with a safe, piped water supply 24/7 should be grateful. Have you hugged your pipes today?