Why does the Hattnau rain retention basin remain empty in heavy rain?

Why does the Hattnau rain retention basin remain empty in heavy rain?

In the past few weeks, heavily pronounced rains have once again illustrated the need for effective flood protection. A discussion about the functioning of the rainwater retention basin there was in particular in the municipality of Hattnau, which apparently was not full as expected during the final regulations. A deeper look at the circumstances reveals, however, that the pool with a volume of 900 cubic meters and a drainage -effective area of 25,000 square meters fulfills a different function.

The function of the retention basin

The rainwater retention basin was not only designed to protect against floods, but should also serve to keep the neighboring meadows drier in normal rains. According to Mayor Harald Voigt, it works perfectly and has no defects. The fact that it remains empty during extreme rainfall is therefore not an indication of a malfunction, but lies in the nature of its purpose.

Historical context of flood protection

Before the establishment of the pelvis, the meadow in Hattnau often had to struggle with water accumulations that were responsible for an inadequate derivation of the surface water. Many citizens remember the puddle formation, which was common at this point before building the pelvis. The switch to modern drainage systems, supported by the renewal of old management systems, represents a decisive improvement that now promotes sustainable water management practices in the region.

The importance of conceptual planning

The retention basin, which was completed at the end of 2020 and cost around 500,000 euros, is not just a short means of protection, but part of a more comprehensive strategy for efficient drainage, especially for the adjacent areas in Selmnau and Hattnau. The planning has already taken into account the challenges in the region and relies on preventive flood protection in order to secure the quality of life of the residents in the long term.

Details for emergency overflow

A further coverage offers the emergency overflow, which is activated in more extreme rains. Mayor Voigt explains that the intended pipelines are designed for normal rainfall, but are not fully able to manage the large amounts of water for heavy rain. This planned system enables part of the surface water to be derived in a controlled manner, while the rest continues to flow through the meadows and thus ensures a natural derivation of the water.

Community responsibility and outlook

The discussion about the retention basin in Hattnau shows how important it is that the community also bears responsibility for local water management. It is a request to raise awareness of the challenges that provide climatic changes to the communities. By understanding the citizens how flood protection systems work and which weather conditions produce which reactions, they can actively contribute to the solutions and show responsibility.

- Nag