The UN’s World Water Development Report from 2015 estimates that the world will suffer a 40% shortfall in freshwater by 2030. While the amount of freshwater on earth is more or less fixed, increasing populations and rapid urbanization means what we have available needs to be clean and conserved to prevent global drought. However, increases in consumption and freshwater used in various forms of manufacturing are projected to increase global demand by 55% by 2050. By analyzing water usage, demand and actual supply in eight cities – Tokyo, London, Cairo, Sao Paolo, Beijing, Bangalore, Mexico City and Houston – we can immediately notice that what’s actually coming out of taps is often less than what’s being pumped out at the source.
Ageing and inefficient piping systems are largely to blame for water leakage, with Mexico City losing a whopping 40% of its water supply daily – the equivalent of 11 cubic meters per second. In other words, the Mexican capital loses more water per day than Houston, London, Bangalore or Beijing even supply. Of the eight cities studied, only one achieves an acceptable leakage rate (under 10%), and that’s the largest city in the world, Tokyo.
From our analysis it seems unfortunately clear that cities in hotter, more drought-prone climates are the ones suffering the highest percentage of water leakages: Cairo comes in a close second after Mexico City, losing a 35% of its water supply daily, while Bangalore, with its modest daily supply of 1425 million liters, loses 32% of that. Surprisingly, and despite a highly regulated water supply system, London leaks 26% of its daily supply – more than five times more than Tokyo.