The Geotechnical Institute warned about the risk of landslides at the Gjerdrum area in 2003. Did anyone listen?

Gjerdrum landslidePhoto: Berit Roald / NTB

Prior to the construction development in Nystulia in Gjerdrum, the Norwegian Geotechnical Institute (NGI) warned that lives could be lost in landslides if the area was developed without measures to limit the risk.

“Larger landslides could cause 10–50 people to lose their lives. Material damage could amount to NOK 20–100 million,” NGI’s report from 2003 about that specific landslide area warned, according to newspaper VG.

The report was written by the NGI before the area in Nystulia in Gjerdrum, which was hit by a large quick clay landslide on December 30, was developed.

Now, questions are being raised about whether the developer and Gjerdrum Municipality knew that the area was marked “red” when it comes to the danger of possible landslides and whether they acted to mitigate the risk if they did.

Recommended avalanche protection measures

In 2005, the Institute followed up with specific recommendations for measures to reduce the risk.

In a press release on January 1 this year, the NGI wrote that the security measures, as far as they know, were carried out.

These measures were of the three following types:

* Relief / excavation of higher terrain to reduce load

* Backfilling of lower-lying terrain and ravine valley to act as a backfill or counterweight to a possible landslide

* Erosion protection of Fjellstadbekken / Tistilbekken

“Assuming that the security measures were implemented, the stability in the area was improved. The danger zone maps that have been made after the development show that the risk of landslides in this area was described as low,” CEO Lars Andresen of the NGI said.

Working on an overview of the documentation

VG has asked NGI to clarify whether the advice was followed, but the department did not want to respond.

“We do not want to contribute to speculating on the cause of the landslide, we are focusing on the acute phase,” NGI’s communications manager Øydis Ulrikke Castberg wrote in an email to VG.

In a press release on Tuesday morning, the NGI said they are now working on getting an overview of the documentation around the landslide area.

“We have a great understanding for the fact that the media is going into construction matters in Gjerdum and also looks at our role,” Lars Andresen said.

The NGI wrote that they will now go through the physical case archive, correspondence with the developer and municipality, and other documentation.

“It is extensive work. The construction case dates back to 2003. Since then, there has been a development of regulations and practices related to design, execution, and control.”

Astrup must answer

On Tuesday, the Socialist Left Party’s (SV) parliamentary representative Lars Haltbrekken sent a written question asking the Minister of Local Government and Modernization Nikolai Astrup (H) to answer whether the security measures were carried out as recommended by the NGI.

Astrup must answer the question within six working days.

© NTB Scanpix / #Norway Today

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