Erosion, Landslide Risks Top Concern as Storms Hit Region
Erosion, Landslide Risks Top Concern as Storms Hit Region
Erosion and landslides remain the most significant storm-related threats facing the Port Madison Reservation, even as a recent atmospheric river combined with King Tides passed through the region with relatively limited local impacts.
Although the Port Madison Reservation avoided the widespread flooding seen elsewhere in Western Washington, the combination of heavy rain and the highest tides of the year can accelerate shoreline erosion and destabilize bluffs, said Alison O’Sullivan, Ecosystem Recovery Program Manager with the Suquamish Tribe’s Natural Resources Department.
“Uncontrolled stormwater running off banks and bluffs can make ground unstable,” O’Sullivan said, noting that overwatering landscaping, removing vegetation for views and filling wetlands compound erosion risks.
“I see it all the time on low, mid and high bank shorelines,” she said. “It is always worse on those properties that have removed all the vegetation.”
O’Sullivan said changing rainfall patterns are contributing to the problem.
“We now have these really long stretches during the summer with no rain, then in the fall we get higher amounts of rainfall than we used to,” she said. “It seems it’s really been the last five to seven years that we have seen this dramatic change.”
While much of the Puget Sound region experienced flooding and high river crests in December, Suquamish saw fewer impacts due in part to the rain shadow effect of the Olympic Mountains, which block much of the incoming Pacific moisture. O’Sullivan said the reservation experienced only minor localized flooding and routine efforts to clear storm drains of leaves and debris.
The contrast was notable compared to flood prone areas such as Hansville’s Point No Point, the Indianola Spit and Port Madison on Bainbridge Island, which have a documented history of flooding due to low elevations, filled tidelands and under-sized culverts. No landslides were reported on the reservation, and conditions did not warrant evacuations. Still, the storm served as a reminder that preparedness remains essential, said Cherrie May, Manager of the Suquamish Tribe’s Office of Emergency Management.
“Suquamish’s relative calm during this storm should not be mistaken for immunity,” May said. “Preparedness today helps ensure safety in the future.”
May encouraged residents, especially those living near slopes and bluffs, to review the Suquamish Emergency Management Mitigation Plan, which identifies erosion and landslides as among the most significant natural hazards facing the community.
The plan notes that landslides remain an ongoing risk during periods of intense or prolonged rainfall and that ground movement can damage utilities, private property and roads, even in the absence of major flooding — similar to the partial collapse of U.S. Highway 2 near Stevens Pass during the December storm.
Residents can stay informed during severe weather or other emergencies by signing up for Suquamish Updates Now and Kitsap Alert. Guidance on managing stormwater and reducing erosion is also available through the Washington State Stormwater Center and local conservation districts via the Washington State Conservation Commission.
