During the great flood in autumn 2000, large parts of central Arvika were under water. The new dam will withstand significantly higher water levels than the city experienced then.

- The dam is built for a so-called 10,000-year flow. Although the dam is slightly lower than the water level in 2000, it is possible to build on a temporary increase that can pass another two and a half meters, says Elin Alsterhag, head of the technical staff at the municipal subsidiary Teknik i väst AB.

Delayed construction

It is a unique pond that is now ready. Something similar in size has not been built in Sweden before, and it has taken time.

The plans were already born after the great flood, but both planning, permitting process and construction itself have taken longer - and become more expensive - than expected.

According to previous calculations, the bill lands at around SEK 230 million. But now everything will work.

- There are no moving parts in the building. Everything is handled manually, and the dust hatches are shipped and lowered by mobile crane or crane truck. We do not want something that can be complicated when it's time.

Exposed location for flooding

Several eight meters long, three and a half tonnes of heavy, steel shutters will be lowered into the concrete foundation as the water rises. A pumping plant will then pump water from the dam area into the Glafsfjord.

- We can lose 30 cubic meters of water per second. It is one of Sweden's largest pumping plants, says Elin Alsterhag.

The level of a dam closure is roughly in line with the quayside in the City Park, the level at which the water begins to flow towards the streets in the center. Over the past 20 years, it has already occurred on three occasions.

- Arvika is one of the Swedish cities that is most in danger of flooding. It is a very large drainage area into the city, but almost flat along the outlet down towards Vänern, says Elin Alsterhag