Tallinn hides 50 kilometers of walkable underground pipes
Tallinna Vesi reveals the Estonian capital sits atop 3,000 kilometers of pipelines, 50 of which are large enough to walk through, as construction continues at the Hipodroom intersection.
Marti Vaksmann, development manager for water and sewerage assets at Tallinna Vesi, has revealed that a vast network of pipelines runs beneath Tallinn — some 3,000 kilometers in total, with roughly 50 kilometers large enough for workers to walk through.
According to Vaksmann, some underground installations reach depths of up to 30 meters, though most sit far shallower. At the Hipodroom intersection, where construction has continued through the summer, crews are working at a depth of about four meters.
A century-old legacy
Most of the existing pipes date back nearly 100 years, from a time when Tallinn relied on a combined sewer system that carried stormwater and wastewater through the same pipes. Now, a separate stormwater pipeline is being built directly beneath the Hipodroom intersection.
Vaksmann said the new infrastructure is being designed to last the next 50 years, accounting for potentially heavier rainfall in the future, so the pipe won't need rebuilding again soon. He noted that while little visible progress may appear at the Hipodroom site, most of the actual work is happening underground, out of sight of passersby.
Life inside the pipes
Vaksmann said he personally enjoys working with pipes and isn't bothered by confined spaces, even though many people find tight spaces uncomfortable. He explained that the crew was currently inside a stormwater collector, but wastewater collectors also exist — and while walking through those is far less pleasant, someone has to do it.
Beyond the large pipelines, the area beneath sidewalks also contains water pipes, sewer pipes, heating lines and various cables. Wherever possible, utility companies route these lines under sidewalks rather than roads, since no buildings sit directly above the current worksite.
