Romanian authorities are changing their approach to restoring water levels at the Cernavoda nuclear power plant, with national waterways management company Apele Romane (Romanian Waters) building a temporary dam on the Danube and state-controlled hydropower group Hidroelectrica releasing additional water from its Olt River reservoirs to support the restart of at least one of the two reactors currently offline, according to G4Media and Radio Romania.

The measures follow several weeks of emergency interventions that included dredging and attempts to sink barges loaded with stone in an effort to raise water levels near the nuclear plant's intake. Those measures produced insufficient results, leaving Romania dependent on more expensive electricity imports during peak consumption hours.

Under the revised strategy, Apele Romane is constructing a transverse guide dam on the Old Danube arm to redirect water towards the intake channel serving the plant. Emergency dredging is continuing in the Cernavoda area under the coordination of the Lower Danube River Administration and Apele Romane.

Hidroelectrica has meanwhile started releasing additional water from reservoirs on the Olt River. According to Antena 3, the company can release around 50 cubic metres per second for five days, although water reserves in the Olt system have also been reduced following several months of drought.

The Ministry of National Defence has resumed support for the emergency works. Military specialists will carry out topobathymetric and geodetic measurements, while military divers will participate in underwater interventions.

The effectiveness of the measures remains constrained by the exceptionally low flow of the Danube. Water entering Romania's section of the river is currently around 1,300 cubic metres per second, roughly one-third of the multi-annual average.

According to the forecast for August 22-29, the flow is expected to remain at around this level for the first three days before gradually increasing to approximately 1,550 cubic metres per second. The expected natural increase would therefore provide considerably more water than the temporary releases from the Olt reservoirs.

The engineering works could eventually have a larger effect by improving the flow towards the nuclear plant's intake, but their impact is unlikely to be sufficient immediately. This leaves the timing of a reactor restart dependent primarily on the availability of adequate cooling water.

Cernavoda's two reactors, each with an installed capacity of 680 MW, have been taken offline because of insufficient Danube water for cooling. Their prolonged outage has increased Romania's reliance on electricity imports during a period of high summer consumption. Out of the 7,500 MW consumed by Romania during the peak hours, it imports 1,00-2,500 MW.