Water situation 29.5.

River Tornionjoki at flood peak, water levels in Lakeland Finland exceptionally low

The flood peaks in rivers in Lapland have mainly been passed, and they remained smaller than average. Tornionjoki river is still rising slightly and will reach its clearly-lower-than-average flood peak at the weekend, whereas Muonionjoki river has started declining.

As a result of the rainfall in the past few weeks, river water levels along the western coast have risen closer to the normal levels at the end of May. In other parts of the country, river water levels are still mainly low.

The exceptionally low-snow winter and early and dry spring have caused the water levels of natural lakes to decline exceptionally early. The water levels of many medium-sized and smaller lakes have already fallen to the lowest seasonal levels ever recorded in the area extending from North Karelia to Pirkanmaa. Efforts have been made to curb the decline in water levels in lakes by limiting flow regulation by means of derogations. The rainfall in May has improved the water situation, but the water levels of Lake Saimaa and Lake Pielinen, for example, will still remain lower than last year, at least for the beginning of the summer.

The drought situation has also posed challenges in reaching the summer target levels for regulated lakes. The discharges of large, regulated water bodies’ outlet rivers, such as Rivers Kokemäenjoki, Kymijoki, Vuoksi and Oulujoki, will be close to the minimum discharges of the season for most of the summer.