Water Level Sounder

In this video simulation you will learn how to take depth to water readings with a water level sounder.  As shown in the pictures and diagram, a water level sounder is a spool of wires with a weighted probe at one end.  The probe consists of two contacts separaed by an insulator.   When the probe is dipped into water, the water completes the electrical circuit.  Within the spool electrical circuit, powered by a battery,  are a buzzer, an on-off switch, a light and a test switch.   When the probe is dipped into water and completes the circuit the buzzer sounds and the light lights up.

The wires of the sounder are embeeded in a teflon tape which is marked in feet, tenths of a foot and hundredths of a foot to measure the depth to water.

Measurements of depth to water in a well are typically taken from a known elevation point on the surface,  This could be the ground surface elevation or an elevation mark on the top of the casing.  The depth to water is then used to compute the water elevation as shown in the figure below.

Procedure for Determining Depth to Water in a Well

1.On the back of the sounder is a brake. Open the brake.

2. Turn on the sounder, and push on the test button to test the buzzer and light.

3. Lower the probe down a well, until the probe buzzer sounds.  Move the probe up and down working your fingrs on the tape to mark the depth when the probe just sounds.

4, Read the tape.


In this exercise you will determine the water elevation in two wells and then using Darcy’s Law you will calculate the groundwater velocity between the wells.

Watch the video to obtain and record the depth to water from the ground surface in well 1. Then using the data in the table below, fill in the form below.


Well Surface Elevation (ft) Depth to Water (ft)  Water Elevation (ft)
Well 1 565.02 See video Enter in form
Well 2 558.58 3.76 Enter in form


Water level form

Water level elevation = Surface elev. - DTW
Water level elevation = Surface elev. - DTW
gradient = (well 1 water elev. - well 2 water elev.) / 200
V = (K/n)dh/dl where K = hydraulic conductivity n= porosity (expressed as a fraction) dh/dl = hydraulic gradient
This field is for validation purposes and should be left unchanged.