Portland Natural Disaster Map 2019 – Floods, Fires, Quakes, and Slides!
We here in the Pacific Northwest enjoy a relatively mild climate year-round — no polar vortexes, and just a few hot days in the summer. In Portland and the surrounding metro areas, most homeowners don’t worry too much about natural disaster, but there are some specific threats to be aware of. Knowing how and where disaster might strike is the best way to be prepared — and if you can avoid buying a home in a high-risk area, that doesn’t hurt either.
- Wildfires. Despite Oregon’s reputation as a moist state, most of its landscapes are naturally dry, and fire is a necessary recurrence for these areas. The Willamette Valley (where Portland is located) and the coast are two exceptions. With higher rainfall and cooler summer temperatures, these areas do see occasional wildfires, but they’re not the norm. Still, there are some wildfire hazards zones are around Portland. Check out the Portland wildfire risk map here. Most homes on the Wildland Urban Interface (where forest meets urban development) are on the West side of Portland. There are also higher-risk zones in the Johnson Creek and Happy Valley areas near Southeast Portland.
- Landslides. Some areas of Portland — primarily in the hills of west Portland — were built on steep slopes with unstable soils, making them vulnerable to landslides. A landslide moving downhill can take trees, roads, and homes in its path, but sometimes the damage is more subtle. Sewer lines crack, or water pools up where it shouldn’t. Oregon geologists estimate that 37,000 people in Multnomah County live in areas at high risk for a landslide. Follow the link for an interactive map showing where those homes are. The Portland Bureau of Emergency Management also has some excellent resources, including a Homeowners’ Guide with tips for landslide prevention on your property.
- Floods. Yes, it rains here in Portland — a lot! With two major rivers passing through the city and the rising ocean not far away, floods should definitely be a consideration for home buyers. The first place to check is the Portland Flood Hazard map. Click on “Layers” to toggle the blue portions of the map showing the 100-year floodplain and the flood area from the last major flood to hit Portland in 1996. (Hint: From here, you can use the drop-down menu to add wildfire, earthquake and landslide risk layers too.) Portland has made major infrastructure improvements since prior floods to reduce the risk to homeowners (including reducing the number of sewer system overflows), and they are still offering reimbursement to some in East Multnomah county who install rain gardens for flood abatement.
- Earthquakes. Like many California cities, Portland is built on top of a major fault line. Ours is known as the Cascadian subduction zone, and geologists estimate that it has a 10% chance of causing a big earthquake in the next fifty years. Smaller earthquakes are also likely. Because earthquakes trigger landslides, West Portland homes again could be at a slightly higher risk. Older homes in Portland should be retrofitted so that they don’t shake off their foundations — that means homes built before seismic building codes were enacted in 1974 in Oregon, and 1980 in Washington. Check out our real estate blog post on earthquake risk in Portland.
For all Portland homeowners, having an emergency supply kit is the best way to ride out a natural disaster. Visit the Portland Bureau of Emergency Management page for more information, including other disasters not covered here. And talk to your Portland real estate agent about what natural disasters might strike your dream home — it’s our job to make sure you’re informed.March 1, 2019