To mark Water Day on 22 March 2026, the City of Chemnitz's environmental department is highlighting the great importance of the numerous small streams. These small watercourses in particular are of great importance for the city, its microclimate, water balance, flora and fauna. Often hidden behind sturdy bank edgings, invisible in pipework or built over, they require special protection.
A natural, meandering stream with sufficient riparian strips can buffer floods better, keep water in the landscape for longer, improve the local climate and provide a habitat for numerous species. A stream is a small ecosystem in its own right. Fish, amphibians, insects and many plant species live in and around the water. Of particular importance is the so-called macrozoobenthos - that is the entirety of small invertebrates such as insect larvae, snails or freshwater shrimps that live at the bottom of the water.
One instrument for protecting streams is the riparian strip. Riparian strips are defined protection areas that are ten metres wide on both sides from the top of the embankment and five metres wide within built-up areas.
Nothing may be erected within these strips. The depositing of objects that could obstruct the flow of water or be washed away is prohibited under the Water Resources Act and the Saxon Water Act. Bank constructions create sections of the watercourse that are far removed from nature with the risk of riverbed erosion and undermining of bank structures. In the event of flooding, rubbish can block culverts and bridges and lead to flooding and massive damage.
The protection and preservation of streams is an important community task. Everyone can contribute. Citizens are obliged to keep the soil and water clean. In addition, all riparian owners are called upon to respect the riparian strips and to develop them in a near-natural way in close coordination with the transport and civil engineering office responsible for maintaining the watercourses or to allow self-dynamic developments.
In addition, all possibilities should be exhausted to limit the sealing of new surfaces and to remove existing sealing in order to minimise the obstruction of groundwater recharge, as low to very low water flows were noticeable in many places in the summer months of recent years in numerous streams. These low water discharges are the result of a previous or ongoing lack of precipitation. If no or very little rain falls over a longer period of time, the streams are mainly fed by groundwater. This is referred to as "base flow".
However, the "groundwater" reservoir is also limited: Low rainfall and extensive surface sealing reduce groundwater recharge. As a result, groundwater levels and the supply to watercourses continue to fall, which in turn increases the decline in water flow in watercourses. The years between 2018 and 2020 in particular were characterised by extremely low precipitation, very high temperatures and above-average sunshine. All of this had an impact on the water levels in streams and rivers, among other things.
Although the water level in watercourses rises rapidly during individual precipitation events, even in pronounced dry periods, it then quickly falls back to the low initial level. The reason for this is that the base flow only recovers when there is a stable rise in groundwater.
Further information can be found at www.chemnitz.de/gewaesserrandstreifen.
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