Mild weather, dense snow in southern Norway limit risk of spring flooding

By Nora Buli

OSLO (Reuters) - Relatively wet and mild weather has kept Norway's hydropower reservoirs well-filled over the winter but also limits the risk of a large spring flood that could see water go to waste, the country's largest producer, Statkraft, told Reuters.

Hydropower is the main electricity source for Norway, a major power exporter, and reservoirs can store huge quantities of water to produce electricity as and when needed, acting like a large battery.

The hydrological conditions look favourable for now, Statkraft hydrologist Gaute Lappegaard told Reuters, but when and how quickly the snow melt will release new water into reservoirs will be key for the longer-term outlook.

While northern Norway has seen a lot of snow this winter, the south, home to the largest reservoir capacity, has seen less precipitation, Lappegaard said.

"And often, that precipitation through the winter has come as rain," he added.

This means that reservoirs remain well-filled and above normal levels for the time of year, with even record levels measured in northern Norway, data from energy regulator NVE shows.

For Statkraft, a key focus in the coming weeks is preparing its reservoirs to receive the water released by the snow melt, and throughout March, the company has sent teams to measure the snow at strategic points, Lappegaard said.

To do so, the teams drill a cylinder into the snow and weigh its contents when pulled up.

"It doesn't help to just measure the metres of snow because snow has different densities, and we need to find out how heavy the snow is. How much water will actually come out of it," the meteorologist said.

This year's milder weather has resulted in less, albeit dense, snow in southern Norway, which is likely to reduce the overall volumes expected after the spring floods, he added.

And with March and April looking mild, the snow should melt more gradually rather than resulting in a flood, allowing Statkraft to maintain control over the timing of its power production, Lappegaard said.

(Reporting by Nora Buli; Editing by Bernadette Baum)