PROLONGED EXPOSURE to flood flows has seriously damaged hydro electric turbines in dams on the River Vltava up-stream of Prague, local engineers said this week.
Hydropower engineers familiar with dams at Slapy, Stechovice, Orlik and Lipno claim damage could have been limited had reservoir levels been properly managed.
The Czech Ministry of Agriculture, is responsible for regulating river flows and flood protection. The dams were constructed by Soviet engineers to provide flood control as well as hydro-electricity.
Reservoir height was intended to fluctuate by between 3m and 5m. But it is claimed that river managers kept water levels in the reservoirs high to maximise surface area for leisure-boats, and to optimise turbine performance.
The turbines were designed to provide energy during short periods of peak demand. According to local sources they were never intended to run for more than a couple of hours at a time.
But rising water levels meant that Ministry of Agriculture river managers were forced to run the turbines constantly to prevent the dams being overtopped.
It is suspected turbine blades and circuitry may have suffered significant damage as a result.
Poor management of water levels is also being blamed for aggravating flooding in towns and villages downstream, as well as in central Prague.
But Ministry of Agriculture department of water management director Pavel Puncochar said that dam operators had been left with no option but to open the gates and allow water to drive the turbines.
Water flow in the Vltava was 5,300m 3/second, compared with an average flow rate of 147m 3/second.
The Vltava dams provided storage capacity of 1bnm 3, Puncochar told NCE, but this was exceeded threefold. In total some 3bnm 3of water washed down the river during the peak flood period, the Ministry of Agriculture has calculated.