Status of water resources in mining region of Goa

3^rd International Conference on Hydrology & Meteorology

September 15-16, 2014 Hyderabad International Convention Centre, India

Gurdeep Singh

Accepted Abstracts: Hydrol Current Res

Abstract :

Water is one of the prime natural resources on which the sustenance and economic development of any State is largely dependent. Unlike most of the rivers in the northern part of the country, none of the rivers in Goa are snow-fed, resulting in sharp imbalances in water availability between the summer and monsoon months. Groundwater basins in the State do not have any significant inter-state component and to a large extent may be considered as ?Hydrologically Land Locked?. Central Water Commission (CWC), Government of India, has estimated the surface water potential of Goa to be 8437 million cubic meters (MCM). Assuming a 10% recharge to groundwater due to the average annual rainfall (3500-4000 mm), the groundwater potential of Goa has been worked out to be 152 MCM by the Central Ground Water Board. Despite such an enormous resource base, the potential utilization of water resources has been low. Factors such as steep topography, short river length, unique physiography, etc., result in low capability for utilization of water resources. Anthropogenic factors like mining activities, agricultural practices and increased built-up area have further widened the demand supply gap. For assessing the surface water quality status of Goa mining region, thirty six (36) water quality monitoring stations were identified and established at various locations along rivers, streams and nallahs etc. Hotspots as per the sensitivity criteria with respect to the water quality deterioration, scenic, aesthetic and recreational aspects and water supply have been established. To assess the status of groundwater, forty five (45) monitoring locations were sited from North & South Goa. To determine the recharging potential of aquifers, Hydrographs were plotted for the wells at all 45 locations. It is seen that wells have good recharge potential and the quantitative impact is primarily persistent in certain areas like Shrigao, Dhandkal (Honda), Pissurlem, Dignem etc. where some wells dried up during the summer season. Several management strategies like settling ponds, laterite rubble wall arrestors, garland drains, overburden and mineral dumps in series (which also help during annual desilting of the ponds), application of Geo-textiles etc. to arrest silt and sediment flows from soil are suggested along with development of central water supply tanks to meet water demand.