Low water levels on Lake Saimaa disrupt boating routes ahead of summer season

Boat operators on Finland’s Lake Saimaa are facing an unusually shallow summer season, with record-low water levels forcing them to remap traditional routes before the start of passenger cruises, reports Finnish broadcaster Yle.

The water level in Saimaa has dropped so significantly that even after reducing outflow to 300 cubic metres per second—the lowest rate since 1992—experts warn it could reach a 50-year low. The Southeast Finland Centre for Economic Development estimates the situation may worsen during peak boating season.

In Savonlinna, operators like Pia Kinnunen’s company, which runs four passenger vessels including the historic S/S Heinävesi, are conducting urgent depth measurements. The 120-year-old Heinävesi, which travels between Savonlinna and Kuopio, typically navigates shallow canals where water levels now hover just 1.8 metres deep—leaving as little as five centimetres beneath its keel.

“We’ll survey the route with our own equipment as soon as possible,” Kinnunen said. “We won’t take risks—if needed, we’ll reroute via deeper channels through Varkaus and Leppävirta.”

Experts advise recreational boaters to verify their vessels’ draft, recalibrate depth sounders, and check updated nautical charts, as low water exposes unmarked rocks and alters shoreline infrastructure. Fixed docks may become dangerously high, trailer ramps too short, and submerged obstacles more hazardous.

Antti Kaipainen, a maritime captain and founder of Veneilysaimaa.com, notes that while official fairways remain safe, “problems arise in harbours and near shores.” Tero Sikiö of the Finnish Transport Infrastructure Agency urges boaters to account for the N2000 chart datum now in use between Lappeenranta and Savonlinna.

Large vessels like Heinävesi require particular caution. “An inch under the keel might suffice by the old saying,” Kinnunen said, “but we need certainty—at least that inch.”