The spa gardens around the Wiesbaden Kurhaus are being made "climate-ready": a flood overflow is being built at the spa pond to counteract the increased heavy rainfall events caused by climate change. This will help protect against flooding of the kind that also hit the Kurhaus Wiesbaden. The images from 2014 are still vivid in our minds, when flooding caused by heavy rainfall caused considerable damage to the Kurhaus and the adjacent underground car park.

For nature conservation reasons, among others, the time window for the construction work had to be set between October 2024 and March 2025 so that the work could be completed by the spring. The construction work in the Kurpark was preceded by extensive preliminary planning in order to minimize the impact on the so-called iceberg hill of the Kurpark and to protect the historic and listed building fabric of the Kurhaus, which will continue to operate during the construction work.

The overflow sill and the new relief channel under the main access to the spa gardens have already been completed. A prefabricated concrete element weighing several tons, which is required for the transition into the Rambach canal (culvert), is also ready on site. The current construction work involves the technically challenging connection of the Rambach culvert to the new relief channel, which runs under the currently closed-off path between the spa park shell and the ice hill. However, unexpectedly high water runoff in the Rambach culvert has made the connection to the relief canal more difficult. For this reason, some of the water will be diverted in the near future to refill the Kurpark pond.

Due to the weather, there were further minor delays in the course of the project and the construction site is now in the final stages of construction. Frost also hindered the construction work in the first few months of the year. For example, the removal of the natural stone at the quarry could not take place as planned due to the winter weather conditions - and the installation of the natural stone cladding on the overflow threshold in the spa park pond was delayed accordingly. The green areas around the pond will be restored in April 2025 in order to preserve the overall appearance of the spa park and at the same time protect the listed building.

The construction project began in September 2024 with the drainage of the Kurparkweiher pond. The water was drained slowly and carefully so that aquatic animals could adapt and retreat, and the pond was then fished out by a fish farm. The draining of the pond was inevitably accompanied by fishing. Fishing took place towards the end of the water drainage.

In addition, the pond was desilted as far as possible. A total of 200 tons of sludge were removed.

The refilling of the Kurpark pond from the natural inflow of the Rambach then began at the beginning of March 2025 and is currently still ongoing.

On Wednesday, December 18, Mayor and Head of the Environment Department Christiane Hinninger received a grant from Hesse's Environment Minister Ingmar Jung in the Kurpark, which covers 25 percent of the approximately 1.3 million euros in construction costs for an overflow sill at the Kurpark pond, the so-called "Schluckbrunnen".

"The funding means a great deal to us," said Mayor Hinninger, expressing her thanks, "because it is an important element in our efforts to prevent or at least minimize flooding for the city of Wiesbaden after heavy rainfall events."

"Even if we cannot completely prevent flooding, it is our goal to support the cities and municipalities in Hesse in the best possible way in order to minimize damage to people, nature and infrastructure," explained Environment Minister Jung at the presentation of the funding decision. "The project is an important step for flood protection around the Kurhaus, one of Wiesbaden's most important landmarks in the heart of the city."

At the lower Kurparkweiher pond (in the south-western area of the pond), a relief structure is being built to drain off water without causing damage in the event of flooding. This will absorb larger quantities of water than the previous drain.

For this purpose, a 10 meter wide overflow sill will be installed and equipped with an underground channel that runs past the concert shell. In the event of flooding, water can also be directed into the Rambach Canal. From there, it flows into the historic Salzbach Canal and is discharged towards the Rhine without causing any damage.

The construction work is expected to be completed by the end of April 2025 .

The Kurparkweiher will not be accessible all around during the construction period, but guests will be able to enter the Kurpark to the right of the Kurhaus and reach the concert shell and the rear entrance to the Kurhaus. The area to the right of the Kurparkweiher between the concert shell and the toilet facilities will be closed in one section for construction vehicles and materials. The side entrance from Sonnenberg Straße, the park entrance from Parkstraße and Josef-von-Lauff-Straße will remain open.

The complexity of the issue of flood protection makes an intensive and lengthy planning and preparation phase essential. The protection against flooding caused by heavy rainfall in the Kurpark is one of numerous measures with which the state capital is preparing for the increasing challenges of climate change - this is how Mayor and Head of the Environment Department Christiane Hinninger explains the construction measures. Wiesbaden's streams carry a lot of water very quickly during heavy rainfall, which increases the risk of flooding.

As past experience has shown, the Rambach, which flows out of a narrow valley, is particularly at risk. To ensure flood protection, a flood retention basin "Im langen Garten" in Rambach and flow-directing measures on the Goldsteinbach are being planned in parallel to the construction of the flood overflow in the Kurpark.

The construction project was approved by the city council and the city parliament of the state capital.

The client is the Wiesbaden City Council. Project management is the responsibility of the Environmental Agency in cooperation with the spa park management of TriWiCon, a company owned by the state capital of Wiesbaden.