South Ostrobothnia experiences flooding after heavy rainfall

Heavy rainfall in the South Ostrobothnia region of Finland has caused stormwater flooding and caused smaller rivers to overflow onto fields and low-lying roads. In Seinäjoki, the Ylistaro Pelma measurement station recorded up to 108 mm of rain on Sunday, with nearly 70 mm falling within a single hour.

Water levels in several lakes, including Alajärvi, Kätkänjärvi, and Kuortaneenjärvi, have begun to rise. The surface of the Kuninkaanjoki river, which flows into Alajärvi, rose by approximately 1.5 meters. To manage these levels, discharge rates from Alajärvi were increased to 35 m³/s to help raise the water level of the downstream Lappajärvi.

While river flows have increased significantly, major rivers such as the Kyrönjoki and Lapuanjoki are not expected to reach flood levels unless further rain occurs. For example, the flow at Kyrönjoki's Hanhikoski rose from 5 m³/s to 20 m³/s, which remains well below the average spring flood flow of 260 m³/s. Thunderstorms also caused localized power outages and communication issues at regulation dams.