📚 How to solve these questions: 12 tips for all 6 Interactive Reading question types, with a worked example for each.
Cities facing water shortages usually reach first for supply. They propose a new reservoir, a longer pipeline, or in coastal regions a desalination plant, because these are visible projects with a ribbon to cut at the end. The alternative, reducing demand, tends to arrive later and with less 1, since nobody opens a leak repair programme in front of the cameras. The arithmetic often favours the unglamorous option. In many older systems a quarter to a third of treated water never reaches a 2, escaping through joints and cracks that are individually small and collectively enormous. Fixing them costs a 3 of what new supply costs per litre delivered, and the water is already paid for. Demand management has a further advantage that is easy to overlook. A reservoir takes a decade to build and 4 a city to one estimate of its future, made before anyone knows how the population or the climate will behave. Pressure management, metering, and repair can be scaled up in stages and adjusted as conditions change. None of this makes new supply unnecessary. A city that has already fixed its network and still cannot meet demand in a dry year has 5 run out of alternatives. The argument is about sequence rather than principle: build after the cheaper savings have been taken, not instead of taking them.