New Early Warning System at the Largest Bulgarian Iskar Reservoir

New Early Warning System at the Largest Bulgarian Iskar Reservoir

End user: NEK EAD Dams and Cascades
Project: Iskar Dam, Bulgaria

The Iskar Reservoir is the largest reservoir in Bulgaria. It is situated on the Iskar River and provides 2/3 of the water supplies for the capital of Sofia. It is also used for generating hydroelectricity. The reservoir has a total volume of 673 million m3, of which 580 million m3 is in use, and the rest is held in reserve. The reservoir has a drainage basin of 1,046 km² and is 25 km long. It is situated at 820 m above sea level, its dam being 204 m long and 76 m high.

In an effort to avert a danger of flooding, laws regulating large hydroelectric dams are very strict in many countries. While a great deal of such effort is put into the design and construction of dams and the associated structures to prevent their failure, comparably less effort is spared to prevent uncontrolled release of water from the reservoir in the event of any other technical or personal failures. The burst of the dam can cause flooding to the whole river valley and potentially wash away towns and villages, causing serious casualties on the local population. Such a huge construction as the Iskar Reservoir poses a potential hazard for many settlements situated rather close to the dam.

Before the implementation of Telegrafia’s project, the existing warning system there was totally obsolete and required complete replacement. Our company’s solution was evaluated as the best one, and the customer decided to build the warning system using the devices produced by the Telegrafia company.

The system consists of a control centre and four Gibon sirens, located at the following places:

– The control centre inside the administration building, close to the Iskar Dam
Siren 1 on a 12 m high mast, close to the crest of the Iskar Dam
Siren 2 on the roof of the municipality building in the village of Dolni Pasarel
Siren 3 on a 6 m high mast, on the bank of the Kokaljane Dam
Siren 4 on the roof of the municipality building in the village of Kokaljane

Each siren installed can sound an alarm to an area of approximately 1.5 – 2 km in diameter.
The control centre has two work stations: one equipped with the Vektra® software and the other equipped with the OCP11 control panel. The communication between the control centre and sirens is ensured by an analogue radio in the VHF band at a frequency of 150 MHz, providing the fastest system activation.

In cooperation with our partner in Bulgaria, the specified equipment and infrastructure of the early warning system were installed and put into full-scale operation. The project was handed over to the customer by signing a protocol at the end of 2016.

This Telegrafia’s water dam solution along with many others has so far proved excellent, providing reliable and rapid warning of the population in emergency situations.

If you seek a similar solution for your dam project, we can assure you that our company is the one you can trust and turn to. We are ready to tailor the project exactly to your needs. Do not hesitate to contact us.