**1. Introduction**

Groundwater is often referred to as an invisible resource, controlled by many natural factors such as physio-climatic conditions, geomorphology, topography, soils and the most important being the geology thereby hampering its sustainable development and management. However, when groundwater is hosted by a hard rock aquifer, its quantifiable attributes become even more unpredictable, and site-specific, thus making it a challenge to devise a suitable management plan. Aquifer mapping is one such tool to effectively manage hard rock aquifers. Aquifer mapping is a process wherein a combination of geological, geophysical, hydrological, and chemical analyses is applied to characterize the quantity, quality, and sustainability of groundwater in aquifers.

The activities include the collection and interpretation of data available from groundwater from various authentic sources. Having plotted the data on maps the data gaps are identified by micro-level data acquisition, that is. through the drilling of bore wells down to the depths of 200 meters and the generation of records of requisite data. Hydrological and hydrometeorological studies for recharge estimation and extensive quality monitoring to assess the potability of groundwater for various uses. Conducting various aquifer performance tests to ensure the yield potential of the aquifer and its sustainability for optimum pumping is the next step followed. Using all these data and data sets various maps have been prepared to draw the 3D geometry of the shallow and deeper aquifers occupying up to 200 m bgl in the area. Both quality and quantity have been assessed to ascertain groundwater availability and safe development (exploitation) in the study area. GIS technology has been used widely for the preparation of various aquifer maps and also to draw the aquifer management plan forming a part of National aquifer mapping (NAQUIM) [1].

In the Maharashtra state of India, Deccan Trap basaltic lava flows are spread over around 82% of the area and form the most prominent aquifer in the entire state. The storage and transmission capabilities of the basaltic lava flow aquifer are very limited due to the inherent absence of primary pore spaces. These basaltic rocks act as aquifers only when they are weathered, jointed, or fractured thus giving rise to secondary porosity and permeability. Due to wide variations in secondary openings, the potential areas for groundwater are generally localized. Thus, Deccan Trap basalt

*Management of Hard Rock Basaltic Aquifer through Aquifer Mapping: A Case Study of Nashik… DOI: http://dx.doi.org/10.5772/intechopen.111644*

possesses a unique challenge to mapping the aquifer both spatially and vertically due to its hydrogeological inhomogeneity.
