3,700 buildings and 280 hectares of building land in 20 communities between Terfens and Wörgl are threatened by flooding and property damage amounting to 850 million euros in a 100-year flood event. Additional alpine power station storage would only reduce this danger to a limited extent in the Lower Inn Valley – and only then if they are actually in operation.
DISTRICT SCHWAZ (red). The water associations in the Middle and Lower Lower Inn Valley are driving forward the planning and implementation of flood protection. The state of Tyrol will support the municipalities in large-scale projects in the coming years with a special contribution and will assume half of the costs incurred by the municipality.
“The flood protection in the Lower Inn Valley is a mammoth project in which the state of Tyrol, along with the federal government, is giving the municipalities and water associations massive support. With a special contribution from the state for major flood protection projects, we reduce the burden on the communities by around half.”
explains LHStv Josef Geisler. The costs for flood protection in the middle and lower Lower Inn Valley are estimated at around 600 million euros (price basis 2019). The municipalities responsible for disaster control have to shoulder around 100 million euros of this. The federal government covers up to 85 percent of the costs for flood protection. ÖBB, ASFINAG, TIWAG and the state road administration are involved as infrastructure providers. For this year, 1.2 million euros in special contributions from the state for the communities have been budgeted.
“We have started operational work in the water associations and are going into detailed planning and project implementation. This incurs costs for the communities”
Mayor Michael Huber from Stans, as chairman of the Middle Lower Inn Valley water association, and Michael Riedhart, mayor from Wörgl, as chairman of the Lower Lower Inn Valley water association, see the special contribution as an important boost at the right time.
Start with retention rooms in Stans/Jenbach and Kramsach/Voldöpp
The next steps in the Middle Lower Inn Valley are the new construction of the stone bridge in Schwaz and the implementation of flood protection for Jenbach.
“There is a risk of jamming at the stone bridge. With the new building, which is scheduled for completion in 2024, we are removing an obstacle to drainage and defusing the risk of flooding in Schwaz. The submission project is currently being finalized for the Stans/Jenbach retention area, which holds 690,000 cubic meters of water. Talks are still needed with the landowners so that we can protect the commercial area and the residential area in the Rossschwemme, which are affected by flooding very early on in the event of a flood and have a high potential for damage, as quickly as possible.”
association chairman Michael Huber outlines the next steps in the central Lower Inn Valley.
Intensive work is also being done in the Lower Lower Inn Valley.
“We are going into the detailed planning for the retention areas and want to start with the Kramsach/Voldöpp retention area, which enables the protection of Brixlegg and Rattenberg and partially for Kramsach and Radfeld. Discussions with the landowners begin in early summer in the Kramsach/Voldöpp retention area. The detailed plan should be available by the end of the year. At the same time, we enter into dialogue with the landowners, citizens’ initiatives and the population.”
the Wörgl Mayor Michael Riedhart explains for the Lower Lower Inn Valley.
Study alpine power station storage is available
The further steps of the water associations build on the existing protection concept and the underlying models and data. The study on the effect of alpine power station storage for the Inn is now also available.
“With the present study, we have now also examined the effects of those large power plant projects on the flood situation on the Inn that are already being implemented or have a realistic chance of being implemented. As we already know from previous studies, the retention effect decreases with distance. The alpine power station storage significantly improves flood protection in the Ötztal, but they are no substitute for flood protection measures on the Inn. For the Lower Inn Valley, the Kaunertal power plant, which is optimized for flooding, would be an additional insurance against climate change after its implementation, for the Ötztal it would certainly be a massive gain in security.”
sums up LHStv Josef Geisler.
Safety gain for Ötztal, additional insurance for Inntal
Specifically, the study examined the effects of the power plant extension currently under construction in Kühtai with a catchment area of 68 km2 and the planned extension of the Kaunertal power plant with a catchment area of 280 km2 on the flood situation in the Inn Valley. It was assumed that the reservoirs would have unlimited capacity for flood retention.
“After the power plant extensions have been implemented, the reduction effect on the Ötztaler Ache is greatest at the gauge in Umhausen, at almost 20 percent. Statistically speaking, the flood wave would be 3.2 percent lower after the two power plant extensions on the Inn at the Oberaudorf gauge on the border with Bavaria were implemented.
, explains Markus Federspiel, head of the water management department. During the 2005 flood, the two additional power station storage facilities in the Tyrolean Oberland would have reduced the flood peak in Oberaudorf by only 1.8 percent or six to seven centimetres.
“Every flood is different. Whether and to what extent reservoirs are effective always depends on the distribution of precipitation. We already know that from other studies.”
retention spaces unchanged
The key question for landowners in the planned retention areas in the Lower Inn Valley is whether the additional power plant storage will change the area required for the retention areas.
“The extent of the retention areas remains unchanged. However, the flooding in the retention areas occurs less frequently and the water levels are sometimes lower. Even if the two additional power plant storage facilities in Kühtai and Kaunertal were already in operation and could therefore be counted towards the protection project at all, this would not result in any significant changes to the project. In order to protect the population and property in the Lower Inn Valley, both the retention areas and the protective dams and walls are needed in full.”
sums up Markus Federspiel.
Read more about flood protection HERE