Ground subsides half a metre at Riihimäki municipal building, officials admit risks underestimated

The ground has sunk nearly half a metre at one corner of the Veturi municipal office building in Riihimäki, forcing its closure this month, Yle reports. City technical director Maria Vasko confirmed that nearby stormwater pump station construction—including deep excavations too close to the structure—triggered the subsidence, acknowledging that risks were not adequately assessed.

Vasko told Yle in an email that responsibility for the damage remains unresolved, with further investigations pending. The 1988-built Veturi has been under an indefinite usage ban since early May, with water supplies cut off and staff restricted to brief, supervised visits in groups of no more than ten to retrieve essential items.

While the adjacent Jokikylä residential development continues—its foundations reinforced with piles and its unstable silt-clay soil stabilised—Vasko stated that deep trenches should never have been planned so close to the municipal building. The city has not yet determined whether Veturi will be demolished or repaired; structural assessments can only begin once surrounding excavations are backfilled.

The closure has disrupted services including urban planning, environmental protection, and employment offices, while external tenants like the Kanta-Häme wellbeing district scramble for alternative premises. Vasko dismissed suggestions that the 2025 rerouting of the Vantaa River contributed to the subsidence, attributing it solely to the pump station works led by contractor Tieluiska. Earlier this month, Tieluiska’s site manager Matti Puuska had told Yle that while ground behaviour is difficult to predict, risks were monitored via 30 observation points, with more added as work progressed.