Willowstick is a geophysical technology company that provides quick and non-intrusive technologies to identify, map and model preferential groundwater connection paths. Like an angiogram that enables medical personnel to see blood flow inside the body, the Willowstick method is able to quickly identify groundwater flow paths. This technique is a powerful tool for finding seeps through or under engineered embankments, leaks through inaccessible liners or for finding preferential flow paths of groundwater.


The Willowstick method is an active geophysical technique. Active methods work by transmitting man-made signals such as percussion waves or electric currents through the earth. The Willowstick method works by introducing an electric current directly into the water of interest. We use the subsurface water of interest as the medium to help us establish an electrical circuit. By measuring the magnetic field generated by the flow of electric current in the water we can identify if there are, and the location of, any preferential water connection paths. This unique method works in the following manner:

  • Electric current is introduced directly into the water of interest at the elevation of interest
  • Earthen materials enhance the electrical conductivity of water
  • The electric current uses the groundwater as a path of least resistance to complete the circuit
  • These electrical pathways generate relative magnetic highs
  • The magnetic field is measured and recorded at the surface using our patented instruments
  • This magnetic field reveals the location and depth of the groundwater connection paths 

This image shows the results of a Willowstick survey. Dark green indicates magnetic high and the blue lines show individual subsurface water pathways. 

The Willowstick method has been ground-proofed in projects completed throughout the world. Willowstick enjoys a high rate of returning customers many of which are recognized as leaders within their respective industries. For a partial client list click here.

The Willowstick technology has the ability to identify and model water flow paths with precision. By directly energizing the water of interest with strategic electrode placement, the Willowstick technology is better suited to identify preferential subsurface water flow paths than other geophysical methods.

The above image is a 3D model of a Willowstick survey that identified a seepage pathway through the dam's rock foundation. 


Why Use Willowstick First? 

Field Technicians collecting measurements of the magnetic field generated by the electric current introduced to the water leaking from the dam.

Field Technicians collecting measurements of the magnetic field generated by the electric current introduced to the water leaking from the dam.

Groundwater characterization is often a frustrating experience. It isn’t easy to understand what is happening with the water beneath our feet. When boreholes fail to provide answers to important questions a typical approach is to drill more holes. In the long term, this approach is cost-prohibitive and may not provide the necessary answers.

Willowstick suggests a more practical approach in characterizing groundwater. Augment data from existing wells with a Willowstick geophysical investigation specifically designed to characterize groundwater flow paths. This approach provides a more comprehensive model of the location and depth of preferential groundwater flow paths. A Willowstick investigation typically identifies specific areas that warrant further investigation while reducing the number of additional wells that need to be installed. The early application of a Willowstick investigation saves time and money by eliminating unproductive remediation efforts.


Mapping Subsurface Water Connection Paths

Mapping Subsurface Water Connection Paths

The Willowstick method uses a low voltage, low amperage, alternating electrical current to directly energize the groundwater by way of electrodes placed down wells or in contact with seeps or leaks. Since groundwater is typically a better conductor of electrical current than the surrounding rocks or earthen materials, the electric current follows the water bearing features that help to complete the circuit between the two electrodes. This electric current, just like all electric currents, generates a magnetic field. This magnetic field is then measured and recorded at the surface of the ground using our patented instruments.

Survey data is normalized to highlight anomalies. These anomalies represent areas where the magnetic field is greater than expected. In the simplest terms, the Willowstick method identifies the preferential connection paths present in the area of investigation. Willowstick has proven effective in mapping and modeling subsurface water systems for over 130 clients in a wide variety of applications.