Hungary is sinking two barges to ensure a key nuclear power plant stays online, Prime Minister Péter Magyar said Saturday.

Europe’s summer of extreme heat has caused the Danube’s water level to hit record lows, affecting power production at the Paks nuclear plant. Nuclear power stations are typically built by rivers and along coastlines so they can use water to cool down reactors.

Hungarian authorities are sinking the two barges to raise water levels so Paks, which provides the country with more than a third of its electricity, can continue to operate normally. The sinking began Saturday morning and Hungarian media are quoting the prime minister saying the water level at the plant has risen by 1 centimeter.