Foreword

Water is essential for sustenance of life on earth. But the problem is unequal distribution of water in space and time. Ancients developed innovative ways to manage water resources to meet their essential needs like drinking water supplies and irrigation. Many parts of India, especially Rajasthan have been practicing water conservation and rainwater harvesting since historical times. Arwari water shed in Alwar district of Rajasthan has brought to focus traditional techniques of integrated water management with community participation. This paper attempts to briefly present the water management scenario in India since Vedic times.

The high reliability of rural and urban settlements on groundwater in India and the individualistic nature of groundwater usage make groundwater management and governance extremely challenging. Groundwater resources development in India, even today, has progressively become synonymous with increasing the accessibility of the resource through more and more sources and meeting the growing demand through the infrastructure of distribution. Management of groundwater becomes selflimiting when the focus is on exploration for new sources, without understanding resource behaviour. On the other hand, experience has shown that bringing aquifers to the centre stage of groundwater management is important. The concept of aquifers changes the way in which communities begin to perceive groundwater and becomes the first step in developing socioecological resilience to groundwater-related vulnerability. Building resilience to groundwater-related vulnerability further includes developing a governance mechanism that strikes a balance between supply management and demand regulation through an understanding of the resource, i.e., the aquifer.Aquifer systems in India are highly diverse and complex because of the variation in their inherent properties such as storativity, transmissivity and groundwater quality. Aquifer vulnerability is a consequence of not only how the rampant exploitation and contamination of groundwater occur, but also how different aquifers react to these fluxes. Moreover, irrespective of the scales of groundwater accumulation and movement, micro-level analysis of aquifers becomes imperative because of the atomistic nature of groundwater access and use. A systematic hydrogeology-based approach that requires delineating aquifers, understanding the dynamics of groundwater and mapping the demand and dependence of community on the resource holds the key to decentralized groundwater governance in India. Such an approach can be undertaken through participatory monitoring, decision support and action.The inherently heterogeneous nature of aquifers and communities in western and central India demand a strategic application of mapping, characterizing and managing local aquifers through a participatory groundwater management protocol. This nuanced approach beginning with aquifers as both a resource and a system, ensures equitable, efficient and hence, the sustainable management and governance of aquifers in this region.

The water sector in Maharashtra is facing critical challenges. First, uneven availability of water over space and time is the biggest challenge and secondly, dramatically increasing competing demands for water from different sectors are giving rise todisputes and conflicts. Of the total water used in the state, about 82% goes to irrigation, 12% for domestic water supplies, 4% forindustrial use, and the remaining for other uses such as livestock, hydro and thermal power generation. With the urban population of about 51 million (45%), and rapidly growing urban centres and industries, there is considerable gap in demand and supply of thestate's scarce water resources. This has posed serious challenges to water security. There can be only limited dependence upon the groundwater resources for the protective irrigation in the State as 85% area is Deccan basalt having limited ground water recharge potential. Also access to safe drinking and other domestics is a challenge in the rural areas of the State. Planning and Management of water resources in a coordinated and holistic manner is needed. Considering the scarcity of water in large part of Maharashtra and substantial utilisation by irrigation sector, there is a need to expedite measures for improving Water Use Efficiency (WUE) so that water saved in irrigation can be utilised for other non-irrigation purposes. The paper gives an overview of the water resources scenario in Maharashtra with reference to surface water and discusses various water management issues that need focused attention. The paper brings out the impact of decision of various water dispute tribunals on the water availability for the State and also the need for inter-basin and intra-basin water transfer. It emphasises the need for upscaling use of Micro Irrigation (MI), Pipe distribution system, large scale integrated MI systems throughout the State etc. for not only to save substantial amount of water but also to help in increase the productivity and quality of agriculture produce. The paper also touches upon the issues of water quality and flood management in the State.

Chemical quality of surface and groundwater of an area is influenced by the climate, hydrological conditions, soil characteristics and geological formation. Irrespective of their source, all natural waters contain some chemical constituents and their quality changes progressively as they traverse over the land surface or infiltrate downward due to various hydro-geochemical processes. Anthropogenic factors also contribute substantially towards quality change of both surface water and ground water. In the present study an attempt has been made to understand the aquifer vulnerability to pollution, at the regional scale (Goa State), which takes into account the intrinsic hydraulic and hydrogeological parameters and environmental impacts. It is noticed that a variety of activities, such as agricultural, industrial and urban land uses, are carried out in the area, thus exposing the aquifers to a wide range of contaminants. Groundwater quality data of Goa state for the pre-monsoon seasons of 2014 and 2018 were obtained from CGWB (Bengaluru) and analysed statistically. A regional scale approach was developed which is known as ABHESHT (Aquifer type, Boundary conditions, Hydraulic Head representing static water level, Environmental impact, Solute concentration, Head variation (Water Table Fluctuation) during pre-monsoon and post-monsoon seasons and Transmissivity). The method has been applied to Goa State, west coast of India and compared with the observed groundwater quality parameters. It is found that the model has successfully delineated the wells which are prone to pollution. Using GALDIT model, seawater intrusion impact was also assessed. The study revealed that the groundwater of Goa State did not show any significant pollution indicator, however, seasonal variations in water quality parameters were observed. It is also found that the North Goa coast as well as the other tourist spots spread over the entire state show signs of pollution at various locations (Anjuna. Baga, Mapusa. Concona etc). This calls for immediate attention from the concerned authorities.