In light of the tragedy in Washington, many are wondering how Portlanders are protected from landslide hazards during review of proposals for new development. My staff in the Bureau of Development Services (BDS) provided the following summary.
BDS regulates and reviews construction and land division projects in areas of potential landslide hazards. Regulations administered by BDS that provide requirements for development on steep and/or sensitive slopes are in City of Portland codes: Title 24 Building Regulations and Title 33 Zoning Code, as well as the Oregon State Structural Specialty Code [Section 1803].
Geotechnical engineers and technicians in the Site Development section of the Bureau review proposals for construction activities on steeply sloped sites, sites located in environmental overlay zones, sites located in “Potential Landslide Hazard Areas” and sites located in Special Plan Districts. Land Divisions in these locations are required to provide geotechnical engineering reports prior to approval of any lot division.
Here are links to two helpful handouts about that process: http://www.portlandoregon.gov/bds/index.cfm?a=72539 and http://www.portlandoregon.gov/bds/article/403947
Permit applications for commercial and residential development on steep slopes requires a geotechnical report. The report must include an evaluation of potential geologic and seismic hazards, including slope instability, and provide recommendations for mitigating the hazard. Site Development staff assigned to these permit applications, review landslide inventory maps prepared by the Oregon Department of Geology and Mineral Industries (DOGAM), the geotechnical report, and the permit drawings.
BDS works closely with other professionals in our regional government to respond to reports of hazardous landslide conditions and emergencies. Here is a link to the Portland Bureau of Emergency Management’s website that provides helpful links to residents whom would like to view the DOGAMI landslide inventory maps of the Portland Metro area - http://www.portlandoregon.gov/pbem/53935. Commissioner Steve Novick is in charge of Emergency Management. If you have questions about landslide hazards not related to new construction, please contact Erika on his staff.