Floating wetlands may improve water quality in Finnish lakes

A pilot project by the Vantaanjoki and Helsinki Region Water Protection Association and the Finnish Scout Association is testing artificial floating wetlands in Lake Märkiö on the border of Hyvinkää and Nurmijärvi to improve water quality.

The structures, made from bamboo, bulrush, jute fabric, and sisal rope, host microbes and planted aquatic vegetation that absorb excess nutrients from the water, reducing eutrophication and blue-green algae growth.

Water protection specialist Reetta Lehto said the goal is to determine the durability of the floating platforms, which are designed to last for years. If successful, the method could be replicated by private individuals on cottage lakes, though permits may be required.

Jussi Tiihonen, chair of the Finnish Scouts’ responsibility group, said the hands-on construction aligns with scouting values and could become part of future camp programs at the Kiljava camp center, which hosts tens of thousands of overnight stays annually.

While Lake Märkiö’s water quality is currently good, the project aims to maintain or improve it. Finland’s Permit and Supervision Agency monitors national blue-green algae conditions, with the first nationwide report of the summer due during Midsummer week, followed by biweekly updates.