Roofs of plenty

DUNGLENA AIZAWAL

Almost every house in Aizawl, the capital of Mizoram, has developed its independent water supply system to counter the acute scarcity of water. Water is harvested as it falls literally from the rooftop. Rainfall is rarely small in quantity in the hilltop town of Aizawl. But over the years, locals found that increasing urbanisation had led to denudation and destruction of mountain springs, creating an enormous water crisis in the process. Carrying water to the town through tankers and trucks became an expensive task. In the midst of plenty, the people of Aizawl were facing a water famine.

The average annual rainfall in this state which rubs borders with Burma is 2,500 mm, but the geological formation does not encourage water retention. Runoff is quick and small streams and springs dry up when there is no rain. When the British came to rule Mizoram about a hundred years ago, they faced the same problem of acute water scarcity. An underground masonry reservoir of 12 lakh gallons with a galvanised corrugated iron (GCI) sheet catchment for collecting rainwater around the tank was the only water source of the government establishment in Aizawl for many years.

To cope with the region's heavy rain, traditional Mizo houses have adopted a sloping structure. Lately, the thatched roofs in these houses are being replaced with GCI ones. Rainwater harvesting is now widespread in Mizoram. A common method of storing rainwater is by placing horizontal rain gutters made up of bamboo or GCI sheets along the sides of a sloping roof. The water pours into a pipe which is connected to a tank