staafpiezometers

A staafpiezometer, also known as a standpipe piezometer, is a simple and cost-effective instrument used to measure groundwater levels or pore water pressure in soil and rock. It consists of a vertical pipe, typically made of PVC or steel, that is installed within a borehole. The pipe is perforated or slotted at the bottom to allow groundwater to enter. A filter material, such as gravel or sand, is placed around the perforated section to prevent soil particles from entering the pipe while allowing water to flow freely. The top of the pipe is usually sealed, and a cap is placed to prevent debris from entering.

To obtain a reading, a dip meter or an electronic water level meter is lowered into the staafpiezometer until it makes contact with the water surface. The depth to the water surface is then measured from a fixed reference point, such as the top of the pipe or the ground surface. This measurement, when subtracted from the reference elevation, provides the elevation of the groundwater table or the pore water pressure at that location. Staafpiezometers are particularly useful in situations where long-term monitoring of groundwater levels is required, such as in environmental studies, geotechnical investigations, and groundwater resource management. Their simplicity and low cost make them a popular choice for widespread deployment.