Wendebach reservoir

Wendebach reservoir
	View from the dam
Location:	In Niedernjesa and Reinhausen , district Goettingen , Lower Saxony
Tributaries:	Wendebach
Drain:	Wendebach with its mouth in the river Leine
Major cities nearby:	Goettingen
	Lower Saxony , Germany
Coordinates	51 ° 28 '12 " N , 9 ° 56' 43" E Coordinates: 51 ° 28 '12 " N , 9 ° 56' 43" E
	Data on the structure
Construction time:	until 1973
Height above foundation level :	15 m
Building volume:	70,000 m³
Crown length:	260 m
	Data on the reservoir
Water surface	8.5 ha
Storage space	1.52 million m³

The Wendebach reservoir is a reservoir with two earth dams, which is located in Lower Saxony in the Göttingen district about 10 km south of Göttingen and 2 km east of Niedernjesa . The lake dammed in 1973 was used for flood protection for a long time. Unsafe in the event of major flood events, its dams were lowered in 2014 and 2015. After the conversion from a reservoir to a bathing lake, the lake was released as a bathing lake on June 7, 2016. The reservoir and its surroundings have the function of a local recreation area.

description

Wendebach reservoir with sunbathing area on the northeast bank, 2007

Island in the lake as a nature reserve, seen from the dam

Greylag geese and Egyptian geese graze on the lawn

The Wendebach rises near Bremke on the border with Thuringia and flows into the Leine south of Niedernjesa . Its catchment area is 36 km². Due to the shape of the surface of the catchment area, considerable amounts of water are supplied to the Wendebach in a short period of time during heavy rain events. The main purpose of the retention basin was to relieve the line and at the same time serve to secure the B 27, which was torn away by floods in 1956. The barrage has dammed the Wendebach , a tributary of the Leine, since 1973 . It lies on the territory of the communities Gleichen and Friedland .

The dam is owned by the State of Lower Saxony . It is a state-owned facility that is the responsibility of the southern operating office of the Lower Saxony State Office for Water Management, Coastal Protection and Nature Conservation (NLWKN) based in Göttingen and Braunschweig. The construction of the Wendebach flood retention basin was a construction project of the state of Lower Saxony and was financed by it. A special purpose association was founded under the chairmanship of the Göttingen district to maintain the reservoir. The dammed water area belongs to the local recreation area of the Zweckverband Erholungspark Wendebach .

The Wendebach reservoir only partially achieved the flood protection desired for federal highway 27 and the town of Niedernjesa , as its two 15-meter-high earth dams would not have been able to withstand a high tidal wave. Its stability was not guaranteed despite multiple renovations.

The lake is also used for local recreation. It was accessed through a parking lot and a circular path. There are various leisure facilities on the site, such as information boards , playgrounds, barbecue area, barbecue hut, toilet and a DLRG watch station. During the school holidays in summer and in good weather, the bathing area of the lake is supervised by lifeguards from the DLRG. In and around the lake you can swim, go boating, fish and barbecue. Often there is nudism and nude bathing, which is tolerated. So far, the lake has been regularly desludged in winter.

history

To protect against flooding, the construction of the retention basin on the Wendebach commenced in autumn 1967 at the instigation of the then Niedernjesa municipality , after the planning approval decision had been issued at the beginning of 1964. The construction time of this first flood retention basin in the Leine area lasted from 1970 to 1973.

The flood retention basin was built with a storage volume of 1.52 million m³. The two dams together had an upper edge of the dam 260 m long, 15 m high and a crown 5 m wide. Relief was provided by a bottom outlet, which can be regulated with a slide shaft, in the course of the turning creek itself. In the event of a stagnation higher than 180 m above sea level. NHN started an overflow on the north side of the basin. During flooding, the Wendebach could be dammed over a length of 2 km, a width of 400 m and an area of 28 ha. The surface of the reservoir was then at a height of 180 m above sea level. NHN , and the reservoir then held 1,520,000 m³ of water.

The following institutions set up the Wendebach reservoir landscape adventure trail at the lake :

Landschaftspflegeverband Landkreis Göttingen e. V.
Zweckverband Erholungspark Wendebach
Regional Environmental Center (RUZ) Reinhausen

In the course of the adventure trail around the reservoir, diverse habitats were found close together. Distinctive objects that are directly related to one of these habitats were erected at various stations in the area. An island in the middle of the lake was a nesting place for birds and was not allowed to be entered.

The "Zweckverband Erholungspark Wendebach" was founded on August 5th, 1974. On January 1, 2006, a new version of the association's statutes came into force, since then the association has been called "Zweckverband Erholungsgebiet Wendebachstausee". The association is sponsored by the district of Göttingen and the communities of Gleichen and Friedland, each of which has equal voting rights. The tasks include the maintenance of recreational facilities, the facilities promoting tourism as well as the maintenance of the cultural landscape and living spaces. After the renovation, the Wendebach reservoir will be completely transferred to the association.

Completed reconstruction of the Wendebach reservoir

The conversion of the Wendebach reservoir is expected to provide more security against dangerous flooding in the region as a result of a dike breach at the Wendebach reservoir. Since then, the Friedland community has been forced to protect the village of Niedernjesa, which is endangered by flooding from the Leine river, with its own dikes. After the conversion of the Wendebach reservoir, the two terminal dams in the middle are about seven meters lower than before, the water level of the bathing lake is still 4.65 meters (measured at the blocking point), and a flood relief system ensures that a very large and rare millennium floods the dam can pass as safely as the current technical regulations provide, according to which such systems as the Wendebach reservoir are planned, built and operated today.

prehistory

The two earth dams had leaked and were therefore unsuitable for flood protection. The state of Lower Saxony feared that the two earth dams would break in the event of extreme floods and that the flood could destroy the village of Niedernjesa and federal highway 27 .

The state planned to dismantle the reservoir because it did not fulfill its planned storage function and there was a risk of flooding. This project was mainly controversial because of the recreational importance of the lake. The concerns about the dismantling of the reservoir had been dispelled by 2010.

Realized conversion plans

At the beginning of July 2011, Lower Saxony's Environment Minister Hans-Heinrich Sander confirmed during a site visit that the Wendebach reservoir would be preserved as a natural paradise and local recreation area and that the budget committee of the state parliament had released the 5.5 million euros required for the renovation. The lake is desludged in the bathing area for 180,000 euros, and the state of Lower Saxony bears the annual maintenance costs of 26,000 euros. The 15-meter-high dam will be cut to seven meters, and in the middle it will have a new overflow channel that will allow so much water through in heavy rain that the dam will hold, but will not endanger the downstream. The flood relief system should ensure that a millennium flood can safely pass the reservoir. However, Sander was “not entirely sure whether the 5.5 million also include better flood protection for Niedernjesa ”.

Completed conversion to a bathing lake and approval as a bathing lake

At the beginning of October 2014, employees of the Lower Saxony State Office for Water Management, Coastal and Nature Conservation (NLWKN) drained the lake content with 130,000 cubic meters of water via the two dams. Mussels and fish were moved to other waters by the Sport Angel Club in Göttingen. The lake is then desludged for bathing.

In June 2015, the Zweckverband and the non-profit employment promotion company GAB renewed the bathing jetty and the bridge over the Wendebach on the circular route of the lake at a price of 42,600 euros. A grant for the bathing jetty was made from LEADER funds. The closing dams were removed by around seven meters and provided with a new flood relief system, which is suitable for discharging a so-called millennium flood; At the same time, the previous flood relief system was backfilled.

The state of Lower Saxony made 180,000 euros available for desludging. That was only enough for the bathing area and the adjacent areas.

In January and February 2016, the reservoir was filled up to the original permanent water level of 171 meters above sea level (4.65 meters water depth at the blocking point). The amphibians quickly found their way back to their original spawning waters at the Wendebach reservoir. Fish and mussels were then restocked in consultation with fishing experts. On June 7, 2016, the lake was reopened as a swimming lake.

Wind farm plans

The Wendebach reservoir is located in the breeding and protection area of the red kite . To the northeast of the Wendebach reservoir, the construction of five wind turbines is planned on the Wüster Berg. There is an expert opinion on the activities of the red kite in the area of the planned wind turbines.

To the south of the Wendebach reservoir there is an area of 24.42 hectares (including the landscape protection area (LSG) in the north) on which three to four wind turbines could be built.

and display information about the image

Panoramic picture from the northeast bank over the lake with sunbathing area, at the level of the bathing area delimited by the swimming line (August 2014)