Elimination of the flood damage from 2013

1. weir system in Gablenz: removal of bank stabilisation and creation of a near-natural watercourse profile

Due to the 2013 flood on the Grundbach in the area of the Gablenz weir (behind the Gablenz outdoor pool), the weir was destroyed and the bank reinforcements severely damaged.

The weir is located to the east of the Gablenz outdoor pool in a garden area with recreational gardens. This area is surrounded by two different allotment garden sites according to the allotment garden law. In the area of the allotment garden site "Jungborn am Forsthaus", the destroyed Gablenz weir will be dismantled and the Grundbach will be adapted to a near-natural state over a length of approx. 60 metres. To this end, a 270 m long construction road will be built and 40 m of trench shoring made of grass pavers and wooden sleepers will be removed. Within individual leasehold gardens, three bridges on steel girders and 50^{m3 of} concrete in the area of the weir will be demolished. The terrain will then be profiled and the ditch bottom and embankments will be stabilised with stone fill. The demolished bridges will be replaced by two new wooden footbridges.

In order to reach the construction site, a construction road will be built via the "Ostheim" path. Once the construction work is complete, this will be converted into a summer path and an access route for emergency vehicles.

The construction work should be completed by the end of June 2017. The construction work is being carried out by Connect Tief- und Ingenieurbau GmbH Wiesenburg from Wildenfels. A total of approx. 190,000 euros is estimated for the dismantling of the weir system.

2. repair of the dam body at Emmerichteich in Wittgensdorf: dismantling and replacement construction of dam - culvert structure, replacement construction of Mönch and creation of wetland biotope/residual pond

The 2013 floods destroyed the hydraulic control system, jeopardising the stability of the dam.

The pond is part of the protected landscape feature "Emmerich pond", which was placed under protection in 1997 and is to be preserved as a biotope. The Emmerich pond is also a legally protected biotope (near-natural small body of water). The biotope will not be significantly impaired. The relevant prohibitions under species protection law will be observed and complied with during the construction work. The creation of a new residual wetland biotope pond will improve the habitat for amphibians.

In the area of the Emmerichteich pond in Chemnitz, OT Wittgensdorf, the dam culvert destroyed by the flood will be renewed and a wetland biotope with a residual pond will be created. For this purpose, the dam body will be replaced over a length of 31 metres with mineral soil with defined soil characteristics. To control the water level, a new monk with an associated pipe conductor will be installed over a length of approx. 25 metres. To create the remaining pond, 250 m³ of sediment will be relocated and a deep water area will be created by excavating soil. The shallow water zone and the remaining area will be replanted. During the construction work, the cross-path will be restored to a length of 91 metres and a width of
3.30 m wide will be restored. The road structure will be adapted to the existing asphalt road in the west and a transition to the existing concrete slabs will be made in the east.

Prior to the construction work, 14 trees had to be felled. The felling work was carried out in February 2017 and the Emmerichteich pond has to be cleared of weeds and small bushes over an area of 2,250^m2. This work will be completed by 15 April 2017. At the end of the construction work, 17 new trees will be planted in the Emmerichteich pond area, calamus and reeds will be planted along the water's edge and the lawns will be renewed.

The construction work should be completed in August 2017. Remaining landscaping work - tree planting - will be completed by the end of November 2017.

The construction work will be carried out by the company Techno-Farm und Service GmbH from Neukirchen-OT Adorf. The costs for the repair of the Emmerichteich pond total approx. 198,000 euros.

3. repair of the Rödelwaldteich overflow in Klaffenbach: new drainage channel and widening of the overflow sill

The 2013 floods destroyed the downstream overflow structure. The Rödelwaldteich - the former Klaffenbacher Bad - is part of the local public green corridor.

In the area of the Rödelwaldteich pond in Chemnitz, OT Klaffenbach, the overflow destroyed by the flood, including the downstream channel, is now being renewed. To this end, approx. 130^m3 of sediment will be removed from the front pond, which is completely silted up and no longer offers any storage space. Subsequently, a shallow water zone with a reedbed zone will be created in the north-eastern section of the forebay in order to green the pond.

The existing permanent water level in the Rödelwaldteich will be maintained with the new construction of the outlet channel and the drop. The overflow sill will be widened to 3.0 metres and narrowed to 2.0 metres up to the end of the drop channel. The channel will be restored for the next 8 metres after the drop channel. Immediately after the pond, the overflow channel is created with a flat slope so that it can be walked on.

In order to increase safety against overflowing of the Rödelwaldstraße (sections HNo. 10 and 11), the existing terrain after the access road to the Rödelwaldteich will be filled in. The embankments will be evenly adapted to the terrain.

Two trees had to be felled in advance of the construction work. The felling work was carried out in February 2017. Once the construction work is complete, four new trees will be planted in the area of the Rödelwaldteich pond and the lawns will be renewed.

The construction work should be completed by the end of June 2017. Remaining landscaping work - tree planting - will be completed by the end of November 2017.

The construction work will be carried out by the company RK Landschaftsbau Dittersdorf GmbH. The restoration of the Rödelwald pond will cost around 114,000 euros.

The Chemnitz (Röhrsdorf) office IWU GmbH Ingenieurbüro für Wasserbau und Umweltplanung, which also prepared the planning documents, was commissioned with the local construction supervision of all three construction measures.

The measures are each subsidised by the Free State of Saxony with funds for flood damage repair.