Trillium Park Drive, a 2-lane local street, has been experiencing a slow-moving landslide since its construction in 1999. The site is located in the Newel Creek drainage area of Oregon City. Since the development of Trillium Park Estates in 1993, there have been 2 prior instances of observed movement along the Trillium Park Drive landslide. Evidence of landslide movement was documented in both early 1999 and January 2006 following periods of intense precipitation. In February 2017, additional movement of the landslide resulted in localized pavement and ground cracks and utility damage within Trillium Park Drive. The City has permanently closed a segment of Trillium Park Drive between Swordfern Court and Canyon Court. Instead, a pedestrian path with landscaping will serve as the connection between both ends of Trillium Park Drive.
Background information including the May 2019 Mitigation Alternatives Analysis Final Report can be found in the Supporting Documents section.