HS Turku | The Aurajoki began to be deepened – Finally, a body rose from the bottom

Turku The Aurajoki, which cuts through the center, has started to be dredged deeper. The purpose is to remove 45,000 cubic meters of mass from the bottom of the river by the end of April.

The dredging works deepen the river along its entire width, but special attention is paid to the river's edges. The purpose is that the large sailing ships of the Tall Ships Races coming to Turku in July would be able to anchor well on the banks of the river.

Construction manager Jouni Hildén The port of Turku says that the depth of Aurajoki varies in different places. In the dredging area located between Martinsilla and the lower reaches of the river, i.e. the harbor, the river is at its lowest point 2.9 meters and at its deepest 7.4 meters. The river is divided into different basins according to the depth of the bottom, and now it is ensured by dredging that the river is as deep as it should be.

In the middle According to Hildén, winter dredging has its own problems. Thick ice and severe frosts make dredging difficult and slow down.

The many ships on the shore of the Aurajoki river, which are still in their places on the shore even in winter, also cause reflection. Such are, for example, the frigate Suomen Joutsen, known to the general public, the barque Sigyn, the minesweeper Keihässalmi, the gunboat Karjala and the former passenger ship Bore, which is currently operating as a hostel.

“We are currently figuring out how we can dredge in the vicinity of various ships. Some ships can perhaps be moved somewhat. These museum ships will not be moved, but on the other hand, there will not be large sailing ships in their place either.”

In the first phase, the Aurajoki will be dredged from the city ferry För to the port. At the beginning of March, the work is supposed to move to the river area between För and Martinsilla.

The river is mostly 60–80 meters wide in its dredging areas.

Turku is a medieval city and its historicity can also be seen from the bottom of Aurajoki.

Hildén says that the dredging work is also monitored archaeologically, so that possible remains in accordance with the Antiquities Act can be collected for further research.

When Aurajoki was last dredged about fifteen years ago, however, no archaeological finds were found.

“Not even the first time. That's when a bunch of bicycles came and also a car with a dead person inside.”

At that time, a man and his car from Tarvasjoki municipality, who had disappeared almost two years earlier, were found at the bottom of the harbor basin.

According to Hildén, at least so far, the authorities have not warned that something similar could now be found.

The old passenger ship Bore is at its standard location in the lower reaches of Aurajoki near Turku Castle. The river bed is being dredged around it, as well as around the minesweeper Keihässalmi and the gunboat Karjalanki on the right side of the picture. Picture: Jonna Rönkä / HS

Dredging mass will, according to Hildén, be mainly fine-grained, earthy material that erosion has eaten up the river and transported downstream. In many places, the river meanders across a typical Finnish clay field landscape.

The dredging mass is dumped at the nearby Lauttaranta dumping area. Before that, the waste that came up with the dredging mass is sorted and delivered for recycling or further processing.

When the work gets going, two different dredging units are looming in the river. Both of them include both the actual dredging vessel and the barge that transports the dredged mass to the dumping area.

Dredging works are carried out from Monday to Saturday between 7 and 6 p.m.

The cost estimate for dredging Aurajoki is around 3.1 million euros. The amount is paid by the city of Turku.

Hildén reminds that even if the ice cover of Aurajoki thickens further with the frost, there is no way to go on the ice of the river near the construction site.

Due to dredging, the ice cover is dangerously thin throughout the rest of the winter.