Gästrike water's investigation indicates that the sprinkler system that pumps water out of Gavleån and then water out over Valboåsen for several years has undermined the ground and when it blew hard this week, the landslide occurred, which is several meters deep.
The hole in the ground was discovered by a private individual.
The investigation continues to see if the sprinkler system can be restarted.
Gästrike water warns to go inside the barriers as there is still a risk of landslides in the area.