Glossary

This term is used in the field of hydrology to describe the channels, such as watercourses and soil drainage, via which water can flow into a water body in the form of wastewater, rainwater or drainage water. Examples of natural receiving waters are open streams that take in and discharge water from other watercourses, groundwater bodies and discharge systems.

Procedure in which chlorine is removed from chemicals in the absence of oxygen. This process is important for the remediation of groundwater contamination, for example.

Removal of river straightening measures and river bed linings with the aim of restoring natural flow conditions.

Remote system monitoring.

This term is taken from the Latin word “retardare” (= delay) and is used in the context of material transport. It describes the deceleration of a substance relative to the moving medium in which it is transported.

In the field of water management, this term refers to the balancing effect of reservoirs on the outflow of flowing waters; see also ->Retention basins.

In the case of flooding, part of the water is stored in reservoirs at the sides of the river and on the flood plains. As a result, the water downstream rises at a slower rate. This in turn delays the flood wave and makes it flatter. The lower the gradient, the higher the level of -> retention. The areas contributing to the retention are known as retention areas.

The process of osmosis involves the diffusion (movement) of a solvent (e.g. water) through a semi-permeable membrane (i.e. permeable only to the solvent). The solvent moves from the area with the lower concentration of the dissolved substance to that with the higher concentration. In the case of reverse osmosis, the natural osmosis process is reversed through the application of pressure. The salts are retained by the membrane and discharged in the form of concentrate.

Collective term for the measures employed to manage bodies of water such that they serve the common good. The aim is to prevent avoidable impairments of their ecological function. In addition, the water balance of terrestrial ecosystems and wetlands directly dependent on these water bodies must be protected, such that sustainable development is ensured. In this context, planning areas are river basin districts, which include the ->basins themselves as well as the groundwater and coastal waters.

Mechanical unit featuring discs mounted on a horizontal axis positioned just above water level; the rotating discs are submerged approximately halfway into the wastewater container. The rotation of the discs supplies the biofilm on the surface of the water with substrate and oxygen.