Vlasina - Water supply channels Strvno and Čemernik

Employer: “Hidroelektrane Đerdap” Kladovo

Consultant: Institute for Water Resources “Jaroslav Černi” Belgrade

Contractor: « Hidrotehnika-Hidroenergetika » ad Beograd and GP » Tončev Gradnja » Surdulica

Beginning of works: June 2011

Water supply channels Strvno and Čemernik are located within the system of Vlasina HPP. The channels are intended for collection of water and its transfer to Vlasina storage. The works at the project started in June 2011. The planned completion of works is in June 2014.

Strvno channel is draining water of Strvnička reka and Preka Rivers. The supply channel is designed as trapezoid channel, closed with concrete slabs. Partially it is constructed from concrete and partially from the stone placed on cement mortar, with its sides in inclination 1:1. Dimensions of the channel are varying along its route. Length of the channel is about 16 km. There are four water intakes: Preka Reka, Strvna, Mrtvica and Polomski potok, as well as number of small intakes at other water courses intercepted by the channel route. Čemernik channel belongs to the system of gravity supply channels of Vlasina lake, and it has function to drain water from rivers Čemernica and Stefanovska reka. Dimensions of the channels are varying along the route. Length of the channel is about 14 km. At the supply channel there are water intakes Stefanovska reka, Čemernik and Dojčinski potok, as well as number of small intakes.

Works on rehabilitation of supply channels Strvna and Čemernik include the following works:

Channel rehabilitation – includes rehabilitation of channel covering – replacement of unstable, damaged and collapsed slabs of the existing covering with new concrete elements, then rehabilitation of damages of channel lining that is made by placing of pre-fabricated concrete elements into the present river bed with previous regulation of the base, such as rehabilitation of channel seepage by placing of geo-membrane or grouting of cracks.

Rehabilitation of outlet structures – includes removal of existing outlet structure and construction of new together with side walls. These works will be performed in dry season when water level in the storage is low.

Rehabilitation of water intakes – includes works at construction of side outlet for river diversion during the rehabilitation works, regulation in front of the intake area, rehabilitation of inlet grid, construction of winter intake, repair of damages at inlet structure, rehabilitation of outlets.

By the schedule of works it is provided to perform works in 2011 at channel Strvna at the stretch from chainage 12+500 to 15+500 due to the reason that it is the most demanding section of execution of the whole works.

The Contractor is performing the works in accordance with the agreed schedule and until the end of the year the Contractor shall make all planned works at the mentioned stretch of channel Strvna.