Modernisation of the Nysa Reservoir
|Company||PORR S.A. (leader), Metrostav A.S.|
|Principal||Regional Water Management Authority in Wrocław|
|Location||Nysa - Poland|
|Runtime||01.2013 - 05.2016|
Taming an element – modernisation of the Nysa reservoir.
Increasing the degree of flood protection in the Nysa Kłodzka valley and supporting flood protection in the Odra valley were the main objectives of the water reservoir reconstruction project in Nysa. The contract was carried out by a consortium led by PORR. Its effects will be felt above all by the residents of Nysa, Otmuchów, Lewin Brzeski and Wrocław. Upon completion of works, about 52,000 residents of Nysa and surroundings, who inhabit an area of approximately 21,700 ha, will benefit from direct flood protection. Indirect protection measures will apply to over 728,000 residents inhabiting an area of ca. 72,900 ha as well.
The water reservoir is also of economic significance as it optimises water management within the region of the Nysa Kłodzka cascade reservoirs. By clearing the Nysa Kłodzka riverbed, it will also allow high waters to run off below the Nysa reservoir. In addition to that, an automated control system permitting to monitor and control the operation of facilities remotely will make it easier to control all infrastructural systems.
The modernisation was one of Poland’s most spectacular ventures and most complicated hydrotechnical investments to be executed in recent years, both in terms of technological and logistical aspects. The works were carried out on an operating reservoir while maintaining the waterflow. The high complexity of the Nysa project necessitated, among others, to manage and coordinate works with multiple stakeholder connections – both inside and outside of the main project and subprojects. The latter were supervised by independent subproject managers.
The reservoir in Nysa is counted among as a first class hydrotechnical building structure covering an area of 3,253 km2. The reservoir’s flooding surface is about 2,080 ha with a capacity of 123 million m3. It is protected from the basin onwards by a frontal flood protection dam in the shape of a horseshoe with the following parameters: height 13.6 m, width in the crown 5 m, length more than 5 km. The sluice structure consists of a 4-span segmental concrete weir. Its segments can be closed one by one, and inside the weir’s pillars two power turbines were installed.
The modernisation of the Nysa reservoir is a key project for increasing flood safety in the south of Poland.© PORR
As part of the project, the water discharge structure of the frontal dam of the Nysa Reservoir was reconstructed and a new bridge and footbridge were built. The automatic control system, the signalling and the visual control system were modernised as well.© PORR
The modernisation project improved the management of the reservoir facilities. The automation of the control system now allows to monitor and control facility operations remotely in the riverbed below the Nysa flood protection dam.© PORR
The reservoir in Nysa spans an area of 2,000 ha and holds more than 120 million m3 of water. It is of supraregional significance and has an essential impact on residents’ flood safety.