In potash and rock salt mining, water from different origins and of different quality levels including river water, groundwater and drinking water is used in many processes.
Raw salt is generally mined by means of drilling and blasting in the underground mining of potash and rock salt. However, salt can also be extracted in a brine plant, where fresh water is introduced into soluble (salt) rock by means of a borehole, resulting in the creation of chambers filled with salt water. The salt-saturated water (so-called brine) is then con- veyed to the surface via another pipeline. The salt is ultimately extracted when the brine evaporates.
During the initial development of a deposit of natural resources, the pumping out of groundwater can lead to a lowering of the groundwater level. Water abstractions during extraction of the natural resources may also be necessary e.g. to keep shafts or excavation pits dry. This so-called drainage and mine water is, if necessary, treated, purified, seeps away or, if applicable, reused, e.g. to maintain moist biotopes or introduced into surface water without being used further.
The use of water by the mining industry is associated with consequences for the water balance. Environ- mental impacts can result from, among other causes, the change in the groundwater level, the flow rate of water bodies and the introduction of drainage and mine water into surface waters.
Water abstraction in the natural resources sector by state in 2016 (in 1,000s of m³)
If the volume of ground or surface water abstracted exceeds certain thresholds, environmental impact assessments must be carried out for the projects concerned.
The implementation of the WRRL into national law took place in Germany through the Water Resources Act, which regulates the protection and use of surface and groundwater at national level. Water abstraction procedures are subject to the reservation on the grant- ing of permission by the water authorities. The water laws of the Federal States supplement and concretise the federal water laws. Overall, the Federal States are left to regulate the water abstraction fees.
In most Federal States, levy rates differ according to the type of abstraction, volume, origin of the water (surface water or groundwater) and the purpose for which the water is to be used. There are also various state-specific deviations from the relevant rules through exemptions or discounts, and these may also apply to the natural resources sector.