Georesistivity 101: Find Water Before You Drill
Contents
Drilling blind is expensive
A failed borewell is one of the costliest gambles a farmer makes. Georesistivity turns that gamble into an informed decision by showing what's underground before the rig arrives.
The core idea
Different materials resist electrical current differently:
- Saturated sand and fractured rock conduct well (low resistivity)
- Dry, compact rock resists current (high resistivity)
Send a known current into the ground, measure the voltage, and the resistance profile hints at where water sits.
Reading a sounding
As we widen the electrode spacing, the current samples deeper layers. Plotting resistance against depth reveals the layering — and, with experience, the likely water-bearing zone.
Spot and depth
Finding the right location is only half the job. Drilling too shallow misses the aquifer; too deep wastes money and can tap poorer water. The survey guides both.
Limits and honesty
Resistivity is an indicator, not an X-ray. We always cross-check against local borewell logs and community knowledge. Used well, it dramatically cuts the odds of a dry well.
