The water crisis
Water is indispensable for life but is finite and therefore precious. Serving pure and potable water to the dense populations in developing countries, especially in India, is a daunting task. According to the World Water Development Report, 1.1 billion people worldwide do not have access to safe drinking water. This figure is expected to touch 2 billion by 2050. 1.6 million die every year due to diseases related to poor sanitation and polluted water supply and 160 million are infected with Schistosomiasis while 133 million suffer from high-intensity intestinal helminth infections.

Millennium development goals
Considering the importance of ensuring sustainable water supply in developing countries, the United Nations formulated the famous Millennium Development Goals (MDGs). Member countries adopted the same and mean to achieve the stated goals by 2015.

Access to safe water- Indian scenario
Though 82 % of the urban population has access to safe drinking water, only 63 % of them have access to tap water. Besides, as against a target of 140 liters per capita per day (LPCD), the average per capita water supply in the country varies from 57 to 160 LPCD. In slum areas, the LPCD stands at a mere 27. Some of these statistics are really staggering. For example, the infant mortality ratio in India is 70, which is closer to some of the African countries. One of the main reasons for this state-of-affairs is the inaccessibility of safe drinking water and intermittent water supply. In Asia only 8 cities, Hong Kong, Kualalampur, Changdu, Osaka, Phnum Penh, Seoul, Shanghai and Tashkant get continuous water supply. Currently, no Indian city gets 24x7 water supply.

Why is intermittent supply bad?
Water supply systems do not operate as designed. Therefore, reservoir capacities are often underutilised. The valves suffer wear and tear. Since, water is supplied by zoning the distribution system, more man power is required. During non-supply hours, pipes are empty and dirt water enters pipelines at vulnerable spots and water is contaminated. Large doses of chlorine or other disinfectants are required to make water safe from microbial pollution. Due to limited hours, peak factor is often in the range of 4 to 6 in most of the systems. Therefore, large sizes of pipe mains are required for strengthening the network to meet the hydraulic requirements. Inconvenient supply hours affect poor people. Large size of storage is required and consumers have to pay for pumping. Also, it results in poor sanitation practices leading to increase in health risks and mortality. Due to intermittent water supply, often meters go out of order resulting in loss of revenue. Besides, due to uncertainty consumers store a large quantity of water and waste it before collecting fresh water again. This adds to a huge undue wastage of precious treated water.