12 Oct 2011

Contest entry: Harvesting rainwater in Brazil

Goal: Give the best example of the end of abundance in water and how people addressed the problem.

RT writes:

The Brazilian semi-arid steppe was never a place abundant in water. Quite the opposite, rain is concentrated in few months of the year. The high temperatures (average 26 C), fast evapotranspiration and strong sunshine year round make life hard for over 20 million people in the Northeastern Brazil. For decades people have suffered with the water scarcity in the region. The severe lack of water reflects in historically the lowest social indicators and highest out migration flows of the country.

A remarkable change came in the past decade with a very simple and ancient technology. Rainwater harvesting (RWH) started as a successful coping strategy against drought. Cisterns are now the most popular word in Northeastern Brazil. Runoff rainwater is diverted from the rooftops of houses via plastic gutters and stored in a 16m3 ferrocement [reinforced concrete] tank. In the region, a rooftop of 40m2 area is able to capture clean water and fill a cistern during the rainy season. It enables a family of five to satisfy drinking and cooking water demand during eight months of drought.
It costs about US$800 to build a cistern. The cost has been split between government and the civil society under the One Million Cisterns Program. The program also fosters social capital. Cisterns are jointly constructed, as households (and neighbors) must provide labor force. Moreover, women are empowered as water care promoters and men are trained as masons, both learning a profession. RWH not only increases the quantity and quality of water available to the households, but also relaxes the time constraint of individuals. It allows them to pursue more productive activities, and puts together communities, building and strengthening ties.
Other entries: TEoA in Mexico City Wyoming's big flows The Great Lakes wake-up call Time for toilet to tap

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