NVE filed an objection to development near landslide in 2014 – VG

– NVE believes that the municipality through the proposed zoning plan does not document that the stability of the area is sufficient for the mapped rapid clay hazard zone and the measures that the plan facilitates, as required by TEK 10 § 7-3 with guidance, wrote the Norwegian Directorate of Water Resources and Energy in its conclusion on the presentation of the case. for the presidency in December 2014.

The development of the Gjerdrum housing and treatment center was completed four years ago and is not far from the area where the rapid clay landslide loosened on Wednesday morning.

On Wednesday morning, all residents of the nursing home were evacuated, according to police.

The Oslo and Akershus county governor also objected on the same background as NVE, noting that geotechnical conditions had to be “clarified and documented in accordance with current regulations.”

Both the county governor and NVE subsequently withdrew their objections after the municipality and a consulting firm, Reinertsen AS, “resolved” the objection to the zoning plan, according to documents in the case VG is in.

The consulting firm must have provided physical samples inside and outside the planning area. At the same time, they compared previous surveys conducted by NGI for the Ask center in 2003 with their own findings.

– Reinertsen concludes that the area can support full development allowed by the zoning plan, the councilor wrote.

Therefore, he concluded that the area could take over development. But he still wrote:

– Overall, development at Ask Center and Nystulia is challenging relative to
quick clay deposits. The councilor will follow up on previous reports from 2003 and establish the necessary requirements that have emerged in accordance with the new NVE guidelines and regulations since July 2014.

– The measures taken in 2007 and 2009 (golf course and planning in Nystulia) have contributed to significantly increase the stability of the buildings in Ask and have allowed further construction stages in the Gjerdrum housing and treatment center, as well as development of the Ask center in its entirety, concluded the councilor.

Thereafter, the presidential politicians also approved development plans.

– It is possible that we could have been more thorough in our investigations of soil conditions containing fast clay during developments. But speculating on that is too early. The whole of Romerike and Gjerdrum consists of large camping areas. These can also change over time, Gjerdrum Mayor Anders Østensen (Labor) tells VG.

You are aware that zoning plans will not be approved with NVE’s objections to the basic conditions of the municipality.

– We are used to receiving objections from NVE. There are incredibly strict requirements associated with such developments. We respond to all objections before plans are approved, says the mayor.

Opposition politician Lars Monsen (Frp) gives the mayor his full support in his description.

– It is too early to say whether we have been thorough enough in our demands to investigate the danger of landslides in this area, says veteran Gjerdrum city council politician Lars Monsen (Frp).

He is in his fourth four-year term on the city council and has been involved in many development cases where rapid clay deposits have basically been an issue.

– My experience is that we have been very aware of this issue. And when plans for developments like the Gjerdrum treatment and life center have been in place, we have relied on well-founded advice from experience, says Monsen.

Consulting firm Reinertsen also wrote in 2015 a companion report on basic conditions in the nursing home.

It is located in an area classified as low hazard by NVE in a rapid clay landslide risk assessment, but near an area with a medium hazard level.

The report indicates about the area of ​​the plot for the nursing home:

“No fast clay has been detected in Reinertsen investigations. In the laboratory, dubious drilling results have been analyzed and it has been confirmed that there is no fast clay. The entire area in question is stable for planned construction,” wrote the geotechnical consultant. in Reinertsen.

He also added that south of the area of ​​the detailed plan for the nursing home, south of Nystullaveien “the calculated safety factor against landslides is not satisfactory.”

Plus:

“Possibly. Landslides that may occur in the southern part will not be retrograde and the natural edge is the stiffer path.”

Regressive landslides are also called shell landslides, and they involve landslides gripping backwards and often sideways in the landslide area.

– The cause of the landslide we must investigate further. It may be natural, it may be due to digging in the creek bed. But we need to investigate this further, says NVE’s representative in the landslide area, regional manager Torill Hofshagen.

– It can also be safely built on fast clay, but extensive evaluations must be made in each individual case, continues the NVE representative.

According to NVE, continuous evaluations are carried out based on updated information from helicopters and drones that are within the area, in addition to knowledge of the ground conditions.

NVE uses the geotechnical expertise of the Norwegian Geological Institute (NGI) in addition to its own professional resources.

– This is an area that has been partially mapped previously, and fast clay is known to be in the area, NVE writes in a press release.

There must be special ground conditions for a rapid clay landslide to occur as in Gjerdrum, and similar large landslides are unlikely to occur elsewhere in Romerike now, adds professional guidance.