Flood defense: Municipality gears up for battle

The fallout from storm Hans: Skellefteå's strategy to tackle increased rainfall and flooding.

Laying cobblestones instead of asphalt, planting new trees, and creating urban green spaces will help reduce the risk of flooding, says Lars Hedqvist.

Laying cobblestones instead of asphalt, planting new trees, and creating urban green spaces will help reduce the risk of flooding, says Lars Hedqvist.

Foto: Ulrika Nohlgren

Skellefteå2023-08-11 09:41

Many residents of Skellefteå will remember the flood of September 2006. The headline in Norran was "Deluge causes chaos in Skellefteå". Boströmsbäcken was flooded, the garage at Odenhuset was filled with water, the ground floor of the Mission Church was flooded and there was a large pool under the viaducts on the E4, water gushed out of Moröskolan so that the manhole cover in the street was lifted, the underpass on Klockarbergsleden was filled with water, and large parts of the artificial turf at Norrvalla were flooded.

In 2019, Norran reported that the County Administrative Board had drawn up maps of urban areas in Västerbotten, showing which areas could be affected by a heavy rainfall, a so-called hundred-year rain, which is 58 millimeters in 30 minutes.

At the time, Bodil Englund, climate adaptation coordinator for the County Administrative Board explained that climate change is expected to increase the intensity of rainfall by 20 to 50 percent in the future.

And major floods can be costly. Floods in Gävleborg and Dalarna in 2021 are estimated to have resulted in damage that cost half a billion kronor.

The darker parts of the map show areas of Skellefteå that could be more severely affected by floods. Purple indicates there could be over a meter of deep water during extreme downpours.

But how is the municipality working to prevent flooding problems in the future?

– We are working on it all the time in our planning, says Lars Hedqvist, planning chief at Skellefteå municipality.

He points out that the changes in the climate are clear.

– It is incredibly unusual what we are experiencing this summer, with a very warm early summer, a rainy period in July, and then a very warm Indian summer. It's not like anything we've seen before, and we feel climate change is moving relatively quickly.

As a result, the municipality plans to conduct new vulnerability analyses this year to simulate the risk of flooding.

– We must continue to monitor the changes that are taking place.

After a cloudburst in 2006, several parts of Skellefteå were affected by flooding. Archive images.

He points to things that can contribute to flooding in Skellefteå. The rainwater drains are sometimes undersized, and at the same time there's a lot of building and asphalting of surfaces, which prevents the water from soaking into the ground. Many large parking lots were also built in the city in the 1960s and 1970s, which made things worse when it comes to drainage.

– We must ensure that the systems are sufficient to allow water to drain. Skellefteå has many parking lots and paved areas. Water accelerates on hardened surfaces. Today, we try to incorporate parking lots into the design and create green areas instead.

What measures have you taken?

– We have made continuous adjustments. For example, we are widening the storm drains in Morö Backe and Morön because there is a lot of construction going on there. We have also increased the size of the sewers.

He points out that the construction of Norrbotniabanan (railroad line) and a new E4 (highway) pose challenges.

– The railroad will be a kind of barrier for the water. We must ensure that drainage is designed from top to bottom. This applies, for example, to Lasarettsvägen, where we have to change the size of the pipes to drain Norrböle.

– We are also looking at the Campus area. There is a lower area. We need to strengthen the pipes there and create water delays.

Lars Hedqvist explains that there areplans to create a green oasis around Boströmsbäcken. The municipality wants to ensure that it does not flood again.

According to Hedqvist, the municipality is also working to strengthen so-called balancing reservoirs. These are parks and other areas where water can be collected and stored until it recedes. One such area is Norrvalla.

–The city center is also an important area. Stone paving, or cobblestones, for example, are better than asphalt. Kanalgatan is an example where we are trying to create an area that can handle water.

But it also has to do with the way streets are built; for example, pedestrian-friendly streets can act as a brake on water. Certain trees can also have a protective effect.

– It is clearly important to have green spaces and more trees. You can see how it works in a rural village where the water drains away and causes no problems.

Lars Hedqvist explains that the trend is towards preserving and creating more greenery in the urban environment, such as the large aspens outside the cultural center.

Could Skellefteå handle a "hundred-year rain" tomorrow?

– We had one almost 20 years ago, and we've been trying to work on the areas that were affected then. We're not finished yet, but all the construction that's going on here creates resources and opportunities for us to implement solutions, says Hedqvist.

What is a Länsstyrelsen?

A "Länsstyrelsen" in Sweden is a County Administrative Board. It's a government agency in each of Sweden's counties and is responsible for various regional administrative tasks. 

Their main responsibilities include overseeing regional growth and development, environmental protection, emergency preparedness, and ensuring that national laws and regulations are followed at the regional level. They act as a link between the local municipalities and the national government.