Landslide policy needs to have a scientific basis can t be based on old data. Get the water out keep the water flowing through gravity drainage.
Structures are last resort.
USGS has developed a possible landslide forecasting technique for the City of Seattle. Lidar imagery to identify old landslides. Need to overcome resistance in some counties to keeping more detailed records. Puget Sound tsunamis differ from those on the outer coast. Puget Sound tsunamis .