NADAG - geotechnical investigations
NADAG is the national database for ground investigations (Nasjonal database for grunnundersøkelser). It collects geotechnical investigations from across the country, so that developers, consultants and public bodies can look up earlier borehole points, soundings and laboratory analyses before new investigations are started. Geotechnics is about how the ground behaves when you build in or on it, and it matters especially in Norway, where large areas have marine clay deposits that can contain quick clay.
The database is operated by Norges geologiske undersøkelse (NGU), the state body for geological mapping and subsurface data. NADAG is a collaboration with Statens vegvesen, Bane NOR, Norges vassdrags- og energidirektorat (NVE) and SINTEF, and data is supplied by public clients, municipalities and consulting engineering firms. The content covers borehole points, rotary pressure and cone penetration soundings, sampling, pore pressure measurements, groundwater data and laboratory results. The data model follows Standard Norge NS 8141 for the exchange of geotechnical data.
The duty to submit data was strengthened after the Gjerdrum landslide in 2020. NVE maintains hazard zone maps for quick clay, and the building regulations TEK17 section 7-3 require buildings and works to be designed and built so that satisfactory safety against landslides is achieved. In practice, this means that both zoning plans and building applications in exposed areas must document a geotechnical assessment, and NADAG is often the first stop for seeing what has been done before.
Access to existing investigations can cut costs and risk in the early project phase: you can assess the need for new investigations, identify problem areas and plan the foundations before committing to a site. NADAG does not replace new investigations, but it gives a crucial knowledge base.
In Placepoint, geotechnical data and ground investigations are shown as map layers, so that early in your analysis of a property you can see which borehole points lie nearby.
How the dataset appears on the map
The dataset is part of the map layer Geology:
From Placepoint's glossary: NADAG - geotechnical investigations
More information: NGU: NADAG, NVE: Landslides and quick clay, DiBK: TEK17 section 7-3
English: National Geotechnical Database (NADAG).
Frequently asked questions
What is NADAG?
NADAG is the national database for ground investigations and collects data from geotechnical investigations carried out in Norway. It lets you find existing boreholes and samples near a planned site.
What type of data is in NADAG?
NADAG holds information about sampling, rotary pressure and cone penetration soundings, groundwater, pore pressure measurements and laboratory results. The data can be used as a basis for geotechnical assessments.
How can NADAG save costs for developers?
Existing NADAG data can reduce the scope of new ground investigations, and therefore the cost. Nearby borehole points can indicate the ground conditions, but they do not replace new investigations.
Who manages NADAG?
NADAG is managed by Norges geologiske undersøkelse (Norges geologiske undersøkelse (NGU)) in collaboration with Statens vegvesen and SINTEF. Data is supplied by municipalities, Statens vegvesen and private consultants.
Where do I find NADAG data?
NADAG is available via ngu.no and NGU's map portal. Placepoint also shows geotechnical data and ground investigations in the map interface, which is useful in the early phase of property analysis.