RAINWATER HARVESTING AS A RENEWABLE SOURCE OF DRINKING WATER IN SALINE GROUNDWATER AREAS- A CASE STUDY OF MEWAT, HARYANA

Abstract

Groundwater salinity is the saltiness or amount of salt (such as sodium chloride, magnesium and calcium sulphate) and bicarbonates dissolved in a water body or soil. It has many harmful effects on environment, infrastructure, public health, urban households, agricultural production, etc. Saline groundwater as a source of drinking water is even more harmful as it has direct implications on the health of the people. Mewat is one of the 21 districts of Haryana, comprising of 5 blocks i.e., Nuh, Punhana, Firozpur Jhirka, Taoru and Nagina. It is located in the south-eastern part of the state and lies between 76° and 77° E longitude and, 26° and 28° N latitude. The economy of Mewat district is primarily dependent upon agriculture, as most of the people are involved in agro-based activities and animal husbandry. The irrigation is basically dependent on canal and groundwater (open wells, tube wells, bore wells). Mewat suffers from extreme lack of freshwater and only 22% of district area has fresh groundwater; other 78% is saline groundwater. The problem of surface water source is at its worse because there are very few ponds in small villages for use. Fresh groundwater is found in the foothills of Aravalli in limited pockets. To solve the problem of water in Mewat district, the state government launched the Rajiv Gandhi Drinking Water Supply Augmentation Scheme in 2005. It includes two technologies i.e., Tube well and Rainy well. Tube well is placed in fresh water pockets located in the foothills of the Aravalli having a high ground gradient. This technology is not suitable for long term as the fresh groundwater is depleting quickly. Rainey well are placed in the vicinity of Yamuna river where recharging is considered to be high. By this scheme, everyday 60,000 cubic metre of water is being supplied to the saline groundwater areas. iii | P a g e Another solution to tackle the dual problem of poor rainwater management and high salinity of groundwater in the form of an innovative rainwater harvesting system was constructed in this area in 2013 with the financial aid from the Department of Science and Technology (GOI). Through this technique, a pocket of freshwater is formed within the existing saline groundwater, which does not mix with the saline water because of the overburden pressure of the existing water. Thus, producing a sizable pool through which freshwater can be extracted as per need. Being an underground storage it remains free from pathogens and other biological contaminants. The lack of any additional storage structure makes the system very cost effective. Thus, being a nearly perfect solution for such salinity problems.