Drought hits rivers in southern Norway

These Copernicus Sentinel-2 images over southeast Norway show the reduced water levels along the country’s longest river, the Glomma, and Sarp Falls.

The images are false-colour and were created using Sentinel-2’s near-infrared channel. This shows vegetation in red, water bodies in dark blue and black and built-up areas in tones of grey. Using this false-colour representation, the retreating water line around lakes is clearly visible, and the churned whitewater created by waterfalls is also visible.

On 11 August 2025, the whitewater from the Sarp waterfall, about 95 km south of Oslo, can be seen clearly at bottom right of the image. The water in Vestvannet lake, connected to the Glomma river system, reaches the natural shoreline.

By 4 August 2026, the white flow of the Sarp waterfall is no longer visible and is greatly reduced compared to the seasonal norm, while the shoreline of Vestvannet lake has retreated, exposing large stretches of sandbank. The countryside surrounding Vestvannet and the Glomma river remains a vibrant red in both the 2025 and the 2026 images, suggesting that vegetation has not immediately suffered from the lack of water in the Glomma.

Nonetheless, Norwegian media have reported that water levels in reservoirs in the south of the country are at 30-year lows, following the lack of rain over summer months.

The southern part of Vestvannet lake, in Ostfold county, is a protected nature reserve. The Glomma, on the other hand, feeds three power plants, generating electricity with hydropower.

Read here for more Earth observation images showing the effects of extreme heat in 2026: Wildfires, drought and extreme heat, 2026