Water is one of the most needful resources on Earth. The increasing population, growing urbanization, and enhanced industrialization over the years have led to increased demand for water all over the world, causing a scarcity of resources and thereby made the world dependent on other sources of water than surface water. Among all, a majorly available and reliable source is groundwater. With diminishing groundwater levels, it endures the need for precise groundwater exploration. The groundwater investigation has been a more significant issue during the last few years due to intolerable distraction, depreciating water quality, and emerging pollution threats to potable resources. To overcome limitations of contemporary groundwater exploration methods present study proposes a new technique utilizing the ‘Light Interference Technique,’ a concept from fundamental Physics. An instrument, NaAvmeter, developed based on Light Interference Technique, was used for groundwater exploration in the current study. A literature survey shows that earth radiations are much dominant over groundwater locations. Empirical investigations were carried out in the Pune city under various site conditions to check the feasibility of application of ‘Light Interference Technique’ for groundwater exploration in the Deccan trap flood basalt terrain. An attempt is also made in the current study to propose a simplified groundwater exploration method using NaAvmeter; an instrument developed based on the ‘Light Interference Technique.’