From an article in New Scientist 17 Sep 02, p 48 about water conservation in India, no definition
given. From Internet:
He cited the building of ‘Johads, which are simple mud and
rubble concave shaped barriers built across slopes to arrest rainwater, as example of community
self-reliance through the empowerment of the local people at the village level. Contributions from each
member of the community, through labour, money, etc, go into the making of these johads. Such
participation gives the community a total sense of involvement in the effort. Since only traditional
technology is involved, training, if required, is easy . These johads have led to water conservation,
better irrigation, better crops, groundwater recharging and elimination of drought conditions which
used to prevail in these areas, and the consequent unemployment and poverty.

http://www.ieindia.org/news/200112/03.htm