Standpipe Piezometers offer a simple and economic method for measuring water pressures in soil and rock. The Standpipe Piezometer (also known as a Casagrande Piezometer) is used to monitor piezometric water levels in vertical boreholes.

The Standpipe Piezometer typically comprises two parts: at its lowest point is a porous piezometer tip; connected to the tip is a riser pipe which continues upwards out of the top of the borehole.

To measure the borehole water level, the filter tip zone is packed with sand and then backfilled above. To isolate pore water pressure at the filter tip, a bentonite seal is required between the sand filter zone and the backfill.

Alternative filter tip types may be driven or pushed into soft soil, and different tip designs are available to suit various types of ground.

Installation methods may vary depending on soil type and site conditions. In drilled boreholes, the tip is lowered to the desired depth, backfilled with sand and bentonite, and the borehole sealed. In soft soils, filter tips can be driven or pushed directly into the ground without drilling. Various tip designs are available to match soil types, including fine-grained soils, coarse sands, and fractured rock. Once installed, water levels can be measured manually using dip meters or automatically with electronic loggers. The water column in the riser represents the groundwater pressure at the tip depth, offering valuable insight into fluctuations caused by rainfall, construction loading, or seasonal variation.

Standpipe piezometers are commonly used in dams, embankments, landfills, slopes, tunnels, and excavations. Their simplicity, durability, and affordability make them ideal for long-term monitoring, even in harsh environmental or construction conditions, since they contain no delicate components and require no external power supply or frequent maintenance, ensuring consistent performance. While they respond more slowly than electronic sensors, proper installation according to internationally recognized standards such as ASTM D5092 or BS 5930 ensures accurate, reliable, and defensible data for engineers, geologists, and project managers. Their proven performance, low cost, and versatility make standpipe piezometers an essential and widely trusted tool in geotechnical engineering, hydrogeological monitoring, and environmental management worldwide.