Rainwater Harvesting

Rain water harvesting is enjoying a resurgence everywhere; not only does it beat the escalating environmental and economic costs of the current water systems, it is also an excellent way to get pollution-free, iron- and arsenic-free soft water. Its techniques were known even in ancient times. Extensive rain water harvesting prevailed 4000 years ago in Egypt, Italy and Greece where residences had paved courtyards to capture rain water and store in cisterns. As early as the third millennium BC, farming communities in Baluchistan and Kutch impounded rain water and used it for irrigation. Submerged township discovered on the sea bed in the Gulf of Cambay, India, at a depth of 90 metres, show huge water storage tank and public bathing tanks that trace the country’s water harvesting culture as far back as 3,000–13,000 years. Even today, you can see many forts and palaces in the arid regions of Rajasthan in India have huge underground tanks which once collected water from rooftops. In the Western Ghats around 130 km from Pune (India), you can find large number of tanks cut into the rocks to provide drinking water to tradesmen who used to travel along this ancient trade route.

Fast urbanization and degradation of communal pastures and forests into barren wastelands have depressed ground water levels in many Asian countries like India, Srilanka, Thailand and Bangladesh. At a time when India is facing drought, it is worthwhile remembering that a wise water management system can avert crises, as several experiments have shown — like for example a tiny village called Neembi in Rajasthan showed that building water harvesting structures like wells and check dams enable farmers to harvest crops despite consecutive years of drought. This had been made possible by the untiring efforts of Rajendra Singh, who won the 2001 Ramon Magsaysay Award for Community Leadership. What Rajendra Singh did was to revive ancient traditions of community-based water harvesting. Under his leadership, the villagers banded themselves together to build check dams called johads, or renovated other defunct old structures to collect rainwater. Some of the stored water in johads percolated down and recharged the water tables below and the wells in the vicinity got water even during dry spells. In the neighboring villages of Bhaonta-Kolyala, villagers were able to revive a dried up river called Arvari by building a network of interconnected johads that helped to recharge groundwater channels.

Every region of India has its own traditional methods of rainwater harvesting. The bawris of Rajasthan are architectural wonders. Some of the structures are between 150 and 1,000 years old.

A bawri in Rajasthan; Source: Couchsurfing

Vavs are stepped wells in Gujarat. These superb works of architecture were built to get the Gods to come down from their abode and sip water in these stone-built, rainwater-harvesting structures. They can resist earthquakes of great magnitude. The following structure is beneath the land surface!

Vadtal vav in Gujarat

Many of these structures are meeting places for the community and a place for worship.

Bringing the people and Gods together: a stepped well in South India; Source: Wikimedia

The following two videos show similar community-based water harvesting in Kenya and other parts of Africa.

The following video shows a medieval Spanish way of rainwater harvesting.

Urban Rainwater Harvesting

You can use rainwater in imaginative ways in your homes.

References:

Rainwater Harvesting News
Rainwaterharvesting.org