Measuring wells for groundwater quantity

Under the Groundwater Act, the province of Zuid-Holland is obliged to establish, maintain and monitor a groundwater monitoring network. The goal of this measurement network is to monitor regional changes in the water system. The provincial groundwater monitoring network is made up of a system of primary measuring wells (introduced by the province), supplemented by secondary and tertiary measuring wells that come from measuring networks of others (such as water supply companies, municipalities or nature managers) or from temporary measuring networks (e.g. spring mills). The groundwater measurement network of the province of Zuid-Holland consists of approximately 260 wells in which groundwater levels are measured and 52 quality wells in which groundwater quality is determined. In each measuring well there are one or more gauge filters at different depths. The number of filters per well and the depth at which the filters are located varies by measuring well and depends on the structure of the substrate at the location where the well is located. A measurement takes place every 14 days in all measuring wells. This measurement takes place automatically using a “diver”, or is performed by an observer. In addition to the permanent observer of the province, there are several individuals who observe one or two measuring wells in their field. The monitoring and maintenance of the groundwater measuring wells is done in collaboration with TNO NITG. They process the measurement data and store them in a database (DINO: Data and Information Dutch Underground). Data, such as groundwater levels, can be accessed from this database via the internet. With the help of the data from the groundwater measurement network, insight can be obtained into the height of the groundwater levels and the quality of groundwater (and the changes thereto) within the province of Zuid-Holland. This information can be used for example in new construction projects, the construction of nature reserves or in solving problems with groundwater (such as groundwater nuisance). In the coming years it will be examined whether there is a need for other information from the groundwater monitoring network than can now be requested via the DINO database and how this information should be made available.