What is "johad"

A johad is a rainwater storage tank principally used in the state of Harayana and Rajasthan, India, that collects and stores water throughout the year, to be used for the purpose of drinking by humans and cattle. In many parts of the state, the annual rainfall is very low (between 450 and 600 mm) and the water can be unpleasant to drink. Rainfall during July and August is stored in johads and used throughout the year. Johads are called as "khadins" in Jaisalmer. They are popularly known as tankis in most parts of the country. Johads were used extensively by the NGO, ' Tarun Bharat Sangh' by Rajendra Singh which led to revival of Alwar district of Rajasthan. Today there are over 4,500 working johads in Alwar and surrounding districts.