Water is one of the most intense issues in India. The lack of equal distribution of water throughout the country creates droughts in certain areas, and floods elsewhere, with few ways to control or regulate such happenings. Groundwater problems are also widespread, with hundreds of bore and tube wells dotting the backyards of many Indian households. With the increasing use of wells to supply water for daily household consumption in India, groundwater levels are dropping and deeper wells must constantly be drilled. Also, pollution of surface water increases the dependence on groundwater, which, in perfect circumstances, would be much less contaminated. However, due to reasons both geogenic and anthropogenic, both groundwater and surface water are severely contaminated throughout India. Once other factors are thrown in, such as politics or religion, water problems become increasingly more complex and difficult to solve, exemplified by water issues in one of the five largest cities in India: Chennai.
Chennai receives 1260 mm/year of rain on average, with 4 large reservoirs throughout the city. 85% of Chennai’s water supply comes from surface water, primarily the reservoirs, during the wet season, and during the dry season, this percentage diminishes to about 10%. The northeastern monsoon, which is the weather pattern that affects the state of Tamil Nadu, and thus Chennai, occurs from October to December. During this time, South India receives erratic rainfall, ranging from 600 mm to 1300 mm each year. Such erratic water supply results in the presence of many non-perennial rivers in South India, as opposed to the high amount of perennial rivers in North India. 1 out of every 4 years, Tamil Nadu experiences what can be classified as a period of drought, further reducing the chance that these non-perennial streams will re-occur and become transient water supplies for those living nearby. The unpredictability of the water supply in Tamil Nadu creates great uncertainty related to reservoir levels during and after the monsoon season. Chennai’s intense reliance on these reservoirs is forced to cease around April, when all water in the reservoirs has been utilized and 90% of the city’s water supply then has to come from the groundwater.
Anthropogenic sources of water contamination are highly interesting to discuss when in India, due to various social, religious, and political factors. There was recently a festival celebrating the elephant headed deity, Ganesha, where worshipers created huge, painted statues of the god, parading him through the streets. After the worship ended, the statues were put into the river, eventually floating down to the sea. Unfortunately, the paint on the Ganesha figurines was toxic, and degradation in river quality due to marine salts and other factors releases high concentrations of pollutants in the water. Political issues are often as detrimental as religious factors in relation to water contamination problems, as changing political parties make it a priority to alter the policies and actions of the previous parties. If one party were to take a stand on industrial waste discharge into the surrounding river and create policies meant to implement such changes, the next party put into power would typically do their best to reverse all policies previously created. Such actions reduce, if not halt, all progress in relation to water contamination solutions.
Geogenic contaminants result from the nature of the rock from which the source water originates. Such contaminants could include arsenic, fluoride, iron, and nitrogen. West Bengal has serious arsenic problems because the river basin sediment contains high concentrations of the element, contaminating groundwater for most of the residents of the state. Andhra Pradesh has high instances of fluoride in the groundwater, resulting in both dental and skeletal fluorosis. Coastal areas have a higher chance of saltwater intrusion into the fresh groundwater sources, with increasing salinity as groundwater levels decrease. Also, the tsunami that occurred on December 26, 2004 adversely affected the quality of both the surface and the groundwater. As the coast of Tamil Nadu was inundated with seawater, reservoirs and recharge areas had increased saline levels, contaminating both ends of the water supply spectrum.
Mitigation efforts in Chennai include bioremediation, where certain plants are introduced which easily absorb toxic metals. Due to high levels of toxic discharge from various types of industry near crucial wetland areas, bioremediation is desperately needed and would greatly help the situation. Mangrove forests have been proven as one of the most effective types of flora to decontaminate wetland areas. Other solutions include check dams, which are small-scale and halt the continuous flow of the river in various increments in order to increase irrigation efforts and recharge groundwater levels in those areas. Injection wells have also been implemented and rainwater harvesting has become mandatory in Tamil Nadu. Water problems will continue to be a huge issue for not only Chennai, but India as a whole, and it will only be through creative and interdisciplinary action that solutions will be found.