A polygon feature class showing potential landslide areas. Used to implement and regulate the City of Seattle's Environmentally Critical Areas policies. Last updated in 2001 via the Seattle Landslide Study. The original data was created from City of Seattle State Environmental Policy Act (SEPA) maps which table digitized in 1995 by Donald Tubbs. Shannon & Wilson added runoff zones & edge smoothing. Areas with indications of past landslide activity, such as landslide headscarps and sidescarps, hummocky terrain, areas with geologic conditions that can promote earth movement, and areas with signs of potential landsliding, such as springs, groundwater seepage, and bowed or backtilted trees. See code section number 25.09.020 of the Seattle Municipal Code for a more complete definition of environmentally critical areas: https://library.municode.com/wa/seattle/codes/municipal_code?nodeId=TIT25ENPRHIPR_CH25.09REENCRAR