| Tistilbekken | |
| Pushpin Map: | Akershus#Norway |
| Pushpin Map Caption: | Location of the river |
| Subdivision Type1: | Country |
| Subdivision Name1: | Norway |
| Subdivision Type2: | County |
| Subdivision Name2: | Akershus |
| Subdivision Type3: | Municipalities |
| Subdivision Name3: | Gjerdrum |
| Mouth Location: | Rana, Norway |
| Mouth Coordinates: | 60.0628°N 11.035°W |
Tistilbekken,[1] [2] also called Fjelstadbekken,[3] is a river in Ask in the municipality of Gjerdrum in Akershus county, Norway. It flows through the residential area Nystulia and from Brådalsfjellet.
Tistilbekken flows into a soil area consisting of a lot of clay. On the night of 30 December 2020, the area was hit by the 2020 Gjerdrum landslide which is described as the most serious in Norway of this type in recent times. Large amounts of precipitation are considered to have had a triggering factor. Tistilbekken's role in the stability of clay and quick clay in the area has been discussed for several years.[4] [5]