What is Groundwater?
​Groundwater is water beneath the surface of the Earth.  Groundwater starts as precipitation and the portion of the rain water that infiltrates beneath the ground's surface, either naturally or artificially, becomes groundwater.  The remaining portion of the precipitation is used by plants, evaporates, or becomes surface water runoff which can either add to groundwater levels in other areas or be increased by groundwater outflows depending on the geology the surface water travels through.  The amount of precipitation that gets absorbed and becomes groundwater depends on the soil type.  Highly porous soils, such as sandy soils, absorb water much faster than soil such as clay which has very small pores. 
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​The saturated soil acts like a sponge and the area where groundwater is present, or saturated, in the soil is called an aquifer, which generally has a boundary defined as its basin.  Groundwater basins are formed naturally over a period ranging from several years to more than a millennium in some geologies.​ Groundwater monitoring is an essential element in any environmental information system. Based upon validated groundwater monitoring data, information is derived on which decisions can be made. Constant monitoring provides the necessary data input for a smart environment and is effectively the basis of the decision-making process concerning spatial planning and climate change adaptation. As in all cases, the rule applies; one single measurement is no measurement.

Why Should Groundwater Levels be Monitored?
​Knowing the groundwater level is important for several reasons, including understanding aquifer levels under static conditions and pumping conditions, determining how the levels interact with local surface water sources, and understanding how surface development has impacted the aquifer.
A groundwater well may have high water levels, however, it may still be unsuitable for drinking water.  Water can easily become contaminated because it is a very good solvent and therefore may contain many dissolved chemicals.  Rain water or surface water can come into contact with contaminated soil while seeping into the ground, and from that point it can become polluted and carry the pollution from the soil into the groundwater aquifers.  Groundwater can also become contaminated when liquid hazardous substances soak down through the soil or rock into the groundwater.
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How are Groundwater Levels Monitored?
​Groundwater level measurements can be made with many types of instruments.  Choosing the right type of equipment depends on factors such as accuracy or ease of the measurement, water quality issues, and the type of pumping activity of the well or nearby wells.
Pressure transducers and automatic dataloggers are ideal for long term or continuous monitoring of groundwater levels.  Pressure transducers are submersible sensors that use some sort of membrane, silicon, stainless steel, or ceramic as a strain gauge to generate an electrical current. These pressure transducers use an absolute pressure value to determine their pressure readings and must be compensated by using external barometric pressure readings.  Dataloggers are generally attached to pressure transducers so that the pressure readings can be recorded for future use.