How to Find Groundwater with Geophysics

Drilling a well without a survey risks failure and wasted cost. A geophysical survey maps the subsurface first so the borehole is placed at the most promising spot — saving drilling cost and raising the success rate.

Resistivity is the most common and economical method for groundwater exploration. Water-saturated layers usually show low resistivity, so aquifers can be identified from the resistivity section. Ideal for broad initial mapping.

Surface Magnetic Resonance Sounding is the only geophysical method that detects the presence of water DIRECTLY, rather than inferring it from resistivity. The IRIS NUMIS instrument measures the signal from water molecules, giving an estimate of water content and aquifer depth with far greater confidence. Highly valuable for water-security projects and drought-prone areas.

After drilling, geophysical logging (gamma ray, resistivity, etc.) with instruments such as the OYO Geologger verifies aquifer layers and well quality — complementing the surface survey.