The flood in western Germany has brought the issue of flood protection back into focus for many.
What actually became of the plans for the Dorfbach - that was what the Lenggrieser CSU was recently about.
Lenggries - Improving flood protection for the Lenggries brooks "is more important than building additional cycle paths", said CSU honorary chairman Manfred Baumgärtel at the annual meeting of the Lenggries local association (we reported).
After all, plans for Dorfbach, Halsbach, Reiterbach and Weiherbach existed, added Baumgärtel, and wanted to know how things would go about their implementation.
Local chairman Bernhard Simon also emphasized how important the topic is.
"Now it has hit North Rhine-Westphalia and Rhineland-Palatinate, next year it might hit us."
Dorfbach could flood the whole town center
In fact, there is a variant decided by the local council in 2012. In the event of a flood, the excess water from the Reiterbach and Halsbach is to be transferred to the Weiherbach in a 450-meter-long pipeline laid in the ground, from where it will flow off in a further 860-meter-long pipeline in the direction of the Isar. That would also ensure that not too much water arrives in the village stream.
According to the calculation of the Weilheim Water Management Office (WWA), the latter could cause the entire town center to flood in the event of a 100-year flood.
Such an event has never happened before.
However, the authority must plan on this basis so that the Free State does not have to pay compensation in an emergency.
Problem with this variant: It is very expensive at around 10.5 million euros.
In addition, a large number of property owners are affected, in whose areas the pipelines have to be laid.
Water management office is working on a cheaper alternative plan
The whole thing somehow "fell asleep and did not get ahead," said CSU parliamentary group leader Josef Wasensteiner in the meeting.
At the beginning of the year he therefore asked Mayor Stefan Klaffenbacher what the state of affairs was actually like.
"The water management office probably wants to make certain changes to the planning" - especially with a view to costs and feasibility.
The local council is currently waiting for the introduction, said Wasensteiner.
In the event of a flood, Dorfbach can absorb even less water than expected
That will probably last until winter, as Markus Brandtner, project manager for the Dorfbach expansion at the water management office, announced when asked. “We are currently coordinating the hydrological fundamentals between the planning community and our office.” At the same time, the engineering office carried out another inspection of the Dorfbach “in order to find ways to improve the existing watercourse without taking up space elsewhere must, ”says Brandtner. In fact, the most recent measurements and calculations by the WWA showed that the Dorfbach can take in less water than expected. If the authority previously assumed five cubic meters per second, in some places it is only four to 4.5.For a 100-year flood event, however, the authorities reckon with 10.8 cubic meters.
Deriving into the Tratenbach only makes sense if the Dorfbach can be upgraded
Instead of the expensive variant, the authorities had recently thought about channeling excess water from the Reiterbach into the Tratenbach and thus relieving the Dorfbach.
“However, the situation remains unchanged in such a way that the amount of water to be expected will be too large for the Dorfbach despite the relief via a possible Tratenbach overpass,” says Brandtner.
That is precisely why one is looking for opportunities to exercise.
The decision is then likely to be made in winter as to whether the variant that has already been decided upon or the Tratenbach transition should be implemented.
Bad Tölz newsletter:
Everything from your region! Our brand new Bad Tölz newsletter informs you regularly about all the important stories from the Bad Tölz region - including all the news about the corona crisis in your community. Sign up here.
