Water International Vol. 35, No. 3, May 2010, 254–269 ISSN 0250-8060 print/ISSN 1941-1707 online © 2010 International Water Resources Association DOI: 10.1080/02508060.2010.487931 http://www.informaworld.com RWIN 0250-8060 1941-1707 Water International, Vol. 35, No. 3, Sep 2010: pp. 0–0 Water International Factors determining informal tanker water markets in Chennai, India Water International V. Srinivasanet al. Veena Srinivasan a *, Steven M. Gorelick a and Lawrence Goulder b a Department of Environmental Earth System Science, Stanford University, Stanford, California, USA; b Economics Department, Stanford University, Stanford, California, USA (Received 6 January 2010; final version received 21 April 2010) Many developing world cities have seen the emergence of informal markets where pri- vate tanker truck operators transport water extracted from peri-urban wells to urban consumers. This study adopted a systems-modelling approach to analyzing the infor- mal tanker market in India. The results indicate that the demand for tanker supply was caused by lack of groundwater availability in private wells as well as unreliable piped supply. The study shows that two groundwater factors are relevant: depth to water and aquifer productivity. Together, these could explain the difference in spatial, temporal and consumer-specific variations in tanker dependence. Keywords: urban; informal; tanker; water market; India Introduction Context and significance of informal tanker water markets for urban water supply In the past 60 years, India’s urban population has increased twice as fast as the population as a whole. This rapid urbanization, accompanied by income growth, is placing immense pressure on water utilities in Indian cities, where infrastructure lags behind. No Indian city currently has a 24/7 water supply. Even in cities where most of the population is con- nected to the piped water system, households typically receive water for a few hours a day and in insufficient quantities (Water and Sanitation Program [WSP] 2003). Consumers typically supplement piped supply from the utility with water from private wells and tank- ers. This article addresses the problem of water provision in Indian cities, a problem with huge implications for human welfare. In particular, the focus is upon the emergence of informal water markets wherein private tanker operators purchase water from peri-urban farmers and transport the water to urban consumers in tanker trucks. Many Indian cities have seen the emergence of informal tanker markets. Londhe et al. (2005) describe tanker markets in six cities in India, where tankers meet about 7% of the demand–supply gap. In a different study, Shaban and Sharma (2007) presented statistics of water supply by source in seven other Indian cities; private tanker markets were preva- lent in six of the seven cities. Although the total quantity of tanker water supplied appears to be a relatively small fraction of the water supplied overall, tanker markets are promi- nent during droughts when supply from other sources is scarce. Moreover, tanker markets are significant in terms of overall household spending on water. *Corresponding author. Email: veenas@stanford.edu