Canal Maintenance

Over the years, the Rauma Canal has become severely eutrophic, meaning it is overrun by aquatic plant life. At the same time, the amount of water in the canal has decreased, which has created challenges for mechanical reaping. To improve the situation, the canal will be deepened by dredging in the first phase.

For the dredging, the contamination of the bottom sediment was investigated between the Vänni bridge and the Vähämaa bridge. According to the results of the investigations, the sediment contained levels of hydrocarbons and heavy metals exceeding the limits. The thickness of the sediment was also investigated and sampled. The sediment is highly contaminated and cannot be taken directly to the reprocessing plant due to its high water content.

The Regional State Administrative Agency of Southern Finland has granted the City of Rauma a permit for the suction dredging of the Canal, the transport of the dredged material through a pipeline to a temporary storage area, polymer treatment of the dredged material and drying in a geotube.

The dredging of the Rauma Canal was postponed until 2024 due to an appeal against the construction of the temporary storage field. The dredging is scheduled to start after Midsummer.