A recent presentation by Oregon’s Department of Geology and Mineral Industries (DOGAMI, gotta love that!) entitled "Landslide 101" was given to area residents. The most recent landslides were in November and December of 2006. The Daily Astorian reported on the presentation, which covered geologic aspects, triggers, and some short and long term solutions in the works by DOGAMI and local officials.
Consultants have recommended installing inclinometers and piezometers in the more recent landslide areas at an estimated cost of $150K to $200K. Here is my favorite part of the article:
Van Dusen (a city council member) said the City Council has been considering installing inclinometers for a long time, but wonder if the expense would be worth it "if the only information that comes back is ‘Yes, the hillside is moving,’" he told the audience.
And that’s what we engineers and geologists are up against when trying to obtain the necessary data for proper engineering design. At least they were able to get some LIDAR data from the USACE.