Published on: 1.10.2019
Information produced by Finnish Environment Institute
Do we have sufficient groundwater reserves?
Most of the domestic water used in Finland is groundwater. There is no need to worry about groundwater running out, however, as it is constantly replenished, whereas the contamination of groundwater is a greater risk.
Groundwater is an important natural resource, which is why the groundwater reserves in Finland have been mapped and classified. There are thousands of classified groundwater areas, which are estimated to produce around six million cubic metres of water a day in total. Of this volume, society uses slightly more than one tenth.
Groundwater areas are not evenly distributed around Finland. They are the most numerous in Lapland, while the smallest number is found on the coasts and around the middle of the country. This means that local shortages of groundwater may occur even if the reserves are plentiful at the national level. The most important aquifers in terms of water supply are found in eskers and Salpausselkä’s large moraine ridges. They usually produce water with a high oxygen content and otherwise good quality.
The soil in good groundwater areas is porous and highly permeable. This is also a risk to the purity of groundwater, because any chemicals, oils and other contaminants spilled on the ground can easily enter the groundwater and contaminate it. Protection plans have been drawn up for high-risk areas, and the use of de-icing salt has been reduced in important groundwater areas.