City details monitoring and short-term measures after shallow landslide on 5th and Commercial

City staff told the Astoria City Council on Jan. 21 that a shallow landslide on Commercial Street between 4th and 6th streets first moved Jan. 7 and reactivated Jan. 14, prompting emergency tree removal and street closure.

Public Works Director Harrington said a geotechnical engineer inspected the site and found the failure to be a shallow landslide in weathered siltstone rather than a deep-seated slide. The immediate hazard—trees and loose material threatening the roadway—was addressed by removing hanging trees and clearing debris. Director Harrington said none of the adjacent structures appear to be in immediate danger per the geotechnical assessment.

The city will monitor the slope through the upcoming wet season before any permanent repair or reopening. If conditions stabilize, staff plan to place concrete barrier blocks (econo blocks) behind the sidewalk to catch falling rocks and debris and to partially reopen the street with the sidewalk closed; geotechnical guidance advised against disturbing the slope until it has been observed through a wet cycle. Staff plan a press release to update the public and said residents at the site had thanked them for the response.

Why it matters: The slope is in a steep terrain area where shallow slides are common and can threaten travel lanes and pedestrians; staff emphasized monitoring during wetter months and intermediate protective measures rather than immediate excavation.

Council follow-up: Councilors asked about timing for a temporary reopening and about hydroseeding. Director Harrington said the city will observe responses to rainfall during the wet season; if the slope settles, the city would install protective blocks and hydroseed appropriate mixes (typical fescue-based mixes used by ODOT/forestry standards) when conditions permit.

Source: Presentation by Director Harrington, Jan. 21, 2025 Astoria City Council meeting.