Tallinn Old Town is Sinking – Urgent Repairs Needed
Over 20 buildings in Tallinn's Old Town show signs of subsidence, and the city is investigating causes and solutions.
Buildings in Tallinn's Old Town have begun to subside, prompting the city to identify causes and find solutions as part of its development plan. In 2024, the Tallinn Environment and Public Works Department conducted a small-scale study to determine whether buildings are subsiding and why. The study was inconclusive, so further investigation is needed.
Toomas Haidak, head of the department's development and planning service, said more than 20 buildings have shown signs of damage. Given the total number of buildings in the Old Town, this is a significant figure, and the actual number may be higher. These buildings require extensive reconstruction, which is a major expense for owners.
One suspected cause is spring water flowing from Toompea Hill into the lower town. Historically, springs on Toompea sent water downhill toward the sea. The area between Pikk and Lai streets forms a bowl where water collects. If it cannot drain, it creates serious structural problems, including cracks and risk of partial collapse, said Toomas Oosalu of the Old Town Society.
The water's path is shaped by historic drainage systems that may no longer function properly. Water from Toompea was once channeled into shafts and pipes. The condition of these shafts is unknown; they may have been damaged during years of construction, Oosalu added.
In addition to spring water, water main leaks and rainfall also affect buildings and streets. If a leak or stormwater gets under a street, it washes away supporting layers, leading to structural issues. Sections of streets are already subsiding, said Kaire Tooming, Old Town development coordinator.
Subsidence is also linked to building maintenance. Tooming noted that many cases are due to deferred maintenance or inadequate upkeep. Severe subsidence requires lengthy restoration work. Haidak said the process is prolonged because no clear responsible party exists. Generally, building condition is the owner's responsibility, but if damage stems from factors beyond the owner's control, there is no authority to turn to for broader solutions.
In the coming months, the department plans to launch an innovation project to analyze whether changes over time can be detected via satellite imagery.
