Both Rožnik hill water storage facilities are situated in the forest on the west side of the Rožnik hill above the Tivoli City Park, along the pathway leading past the Cekin Mansion, to the top of Rožnik hill. The old Rožnik hill water storage facility with a volume of 3,030 m3 became operational in May 1890, whereas the new facility was built in 1945 and has a capacity of 2,162 m3. Both facilities are connected with the water supply network by two pipelines leading from Kleče and from the Ljubljana city centre.
The 126 years old mechanical installations, primary feeder and water pipe fittings were desperately in need for renovation. The reconstruction of mechanical installations in both Rožnik water storage facilities comprised incoming and outgoing pipelines within the fenced area of the facility, water pipe fittings and pipe connections.
The reconstruction of the old water storage facility has been designed in such a way as to minimise the number of interventions into its construction work. The existing pipes penetrating the walls had to be retained. The interior of the pipes and external visible parts were sandblasted and protected by coating suitable for applications where the coating is in contact with foodstuffs.
New openings were drilled in the new water storage facility into a 2,000 mm thick wall, and stainless steel pipes were laid through the openings for filling and draining of the water storage reservoir.
All newly installed pipelines in both water storage facilities are made of stainless steel INOX AISI 316, and all additional welding work was performed by our qualified workers. Filling and draining of both water storage facilities is carried out via PAM Eurostop flaps provided with AUMA electric motor drives, which ensure an undisturbed water circulation.
Due to ageing of the currently installed cast iron pipes and damages inflicted to the water supply network by the roots of the adjacent trees, water supply connections outside the buildings had to be replaced in addition to mechanical installations in the fitting compartments. PAM Natural nodular alloy pipes proved most appropriate for this purpose. Due to large flow rates and requirements dictating small pressure losses, DM 500 was determined as maximum nominal pipeline diameter.
A water-meter shaft was built before the connection to the existing main to monitor water consumption, accomodating two ABB WaterMaster magnetic-inductive flow meters, which are used for water consumption monitoring in both incoming/outgoing pipelines.
At the same time, a reconstruction of the existing platform at the entry into the water storage facility was carried out.