Measuring groundwater and salinity levels should be done regularly (about once a fortnight during irrigation and monthly during winter). To gain a good understanding of a groundwater system, groundwater levels should be monitored over several years.
There are two types of bore used to monitor groundwater levels and quality:
- Test wells measure the level of the local watertable and can highlight the potential for salinity before it becomes a problem. Test wells placed at several locations can provide an overall picture of groundwater levels in an area to assist in making salinity management decisions.
- Piezometers are special monitoring bores that are used to monitor regional groundwater levels. Piezometers measure the water pressure in an aquifer or the soil. They can also be used to measure the depth to the watertable and the quality of water.
Groundwater depth can be measured using a tape measure with a bell shaped cylindrical 'plopper' or a fox whistle attached that makes a distinctive sound when it touches the water surface in the bore. The same point at the top of the bore should be used to measure to each time depth measurement is taken.
To measure the salinity, water can be removed from the bore using a bailer or small pump and collected in a clean container for measurement with an electrical conductivity meter.
When measuring salinity in a bore, several bore volumes should be pumped or bailed after the groundwater level has been measured. This ensures the water being tested in the bore is representative of the surrounding groundwater (i.e. it is not stagnant).