Portland, Oregon water damage restorationfor a city that rains 157 days a year

Portland is not the wettest city in the country by total rainfall, but it is one of the most persistent. The airport averages close to 37 inches a year and downtown about 44, spread over roughly 157 days with measurable precipitation. ^[1] November, December and January are the wettest months; July and August are almost dry. That pattern means the ground around foundations is wet for months at a time, and water problems tend to show up in winter.

Most of that rain is steady and moderate, but several times a winter an atmospheric river arrives: a long band of moisture from the subtropical Pacific that can drop several inches in a day or two. Those storms overwhelm gutters, fill window wells, push water through basement walls and stress the sewer system.

The wet season also slows drying. When the outside air is cool and near saturation, opening windows does not dry a house. Contractors in Portland generally dry closed up, with dehumidifiers doing most of the work, which is covered on our structural drying page.

Snow and ice are less frequent but more damaging when they come. Portland averages only about four inches of snow a year, so many houses are not built for freezing. When cold air pours in from the Columbia Gorge, pipes in crawlspaces and exterior walls are at risk.

Portland's inner neighbourhoods are full of early twentieth-century houses: bungalows, craftsman homes, foursquares and Old Portland styles, many with full or partial basements. Those basements were often built as storage and utility space with poured concrete walls and no waterproofing, then finished decades later with carpet, framing and drywall. When water comes through the wall, it gets behind all of it. See flooded basement cleanup.

Postwar neighbourhoods further out, and much of east Portland, Gresham and the suburbs, have more ranch houses and split-levels over crawlspaces. A plumbing leak or groundwater there ends up on the crawlspace vapor barrier, out of sight. Our crawlspace water damage page covers that.

Older Portland houses often have plaster walls and old-growth fir floors. Plaster holds water longer than drywall and needs patient drying. Fir floors are often worth drying in place rather than replacing. Houses built before 1978 may have lead paint, and older homes may have asbestos in some materials, so a careful contractor asks about the age of the house before cutting into anything.

Newer infill, townhouses and apartments bring their own issues: water from an upstairs unit, shared walls and building management to coordinate with.

Portland sits where the Willamette flows into the Columbia, and its flood history is mostly a river story. In the Christmas flood of 1964, an atmospheric river brought warm rain onto frozen ground and fresh snow, and the Willamette rose about 12 feet above flood stage in Portland. ^[5] A log raft damaged the Hawthorne Bridge, which was closed for a year.

In February 1996, heavy rain and snowmelt sent the Willamette to a crest of 28.6 feet, about 10.6 feet above flood stage. Volunteers sandbagged the downtown seawall, and the water came within inches of overtopping it. Upstream, downtown Oregon City was underwater for days. In southwest Portland, several houses were damaged and a landslide closed part of SW Fairmount Boulevard for weeks.

Johnson Creek in southeast Portland and Gresham has a long history of overbank flooding that affects homes along its banks, and the city has worked on floodplain restoration there. Homeowners near Johnson Creek, the Columbia Slough or other mapped floodplains should check the city's flood maps.

For most Portland homeowners, though, the everyday risk is not a river. It is groundwater, surface water, a failed pipe or a backed-up drain.

Parts of Portland, mostly older neighbourhoods, are served by combined sewers that carry both stormwater and sewage in the same pipes. During heavy rain, the volume in those pipes rises sharply. To reduce overflows into the Willamette River and the Columbia Slough, the city built the Big Pipe tunnels, which store and carry combined flow during storms. ^[7]

For a homeowner, the practical concern is the private sewer line from the house to the public main. Roots from Portland's mature street trees, older clay or concrete pipe and stormwater getting into the line can all lead to backups. The lowest drain in the house, usually a basement floor drain, is where it shows first.

Water that comes up from a drain is treated as contaminated. If you see it, stop using water in the house and see sewage backup cleanup. If neighbours are having the same problem, report it to Environmental Services, the city's sewer and stormwater utility.

Gresham and Troutdale, on the east edge of the metro, sit closer to the Columbia Gorge and often feel the cold east winds first in a winter storm. Crawlspace houses are common, and pipe freezes during cold snaps are a regular cause of water damage. Johnson Creek runs through Gresham as well.

Lake Oswego and West Linn sit along the Willamette, with hillside neighbourhoods and lakeside homes. Hillside drainage, daylight basements and homes near the water each bring their own risks. The Tualatin River meets the Willamette at West Linn; its highest recorded flow came on February 10, 1996.

Oregon City has a historic downtown that was submerged for several days in the 1996 flood, and older homes on the bluffs above. Happy Valley, Canby and Sandy are a mix of newer subdivisions and older rural properties, some on septic systems.

Wilsonville and Tualatin, along I-5 to the south, are covered on our Beaverton page along with the rest of Washington County's suburbs.

Contractors working on Oregon homes are licensed by the Construction Contractors Board. Its online license search shows whether a license is active and whether complaints are on file. It is worth a minute before anyone starts cutting drywall.

Some repairs after water damage, such as electrical, plumbing or structural work, may need permits from the City of Portland or the relevant city. The contractor you speak with can tell you whether the rebuild involves any of that.

Calling this site's number puts you through to an independent Portland-area contractor; whatever you agree on that call is between the two of you.

Portland homeowners face the same coverage gaps as anyone else, but the city's mix of basements, floodplains and older sewers makes them more visible. Standard homeowners policies commonly cover sudden plumbing failures and commonly exclude groundwater, outside flooding and, unless an endorsement is added, sewer backups.

If your house has a basement, ask your agent specifically about sewer and water backup coverage. If you live near Johnson Creek, the Columbia Slough or other mapped flood hazard areas, ask about flood insurance, which is usually a separate policy. The City of Portland lists contacts for floodplain and insurance questions on its flooding page.

For help with an insurer's handling of a claim, the Oregon Division of Financial Regulation takes questions and complaints. Our guide on working with your insurance adjuster covers what to document.

Portland's mature street trees are part of the city's character, and they also play a part in its water damage. Fall leaf drop fills gutters just as the rainy season starts, and overflowing gutters dump water against foundations and into walls. Roots find their way into older sewer laterals through joints and cracks, leading to slow drains and backups.

During ice storms, heavy branches break and bring down power lines, which leaves houses without heat and pipes at risk of freezing. Occasionally a falling limb punctures a roof, letting rain straight into the attic.

None of that is a reason to resent the trees. It is a reason to clean gutters more than once a season, have an old sewer line inspected if drains are slow and know where the main water shutoff is before the next storm.

Portland's west hills and parts of southwest Portland are built on steep slopes where water management matters. In very wet winters, saturated soil on hillsides can slide, as it did on SW Fairmount Boulevard in 1996. Even without a slide, hillside homes deal with water running downhill toward the uphill side of the house, daylight basements that sit partly below grade and retaining walls that hold back wet soil.

For those homes, good drainage on the uphill side, clear gutters and downspouts piped well away from slopes, and regular checks of retaining walls and drains help. If water is entering a hillside house during heavy rain, a contractor can deal with the water damage, and a geotechnical or drainage specialist may be needed for the cause.

A large share of Portlanders rent, and many others live in condos and townhouses with shared walls and floors. Water damage in those buildings involves more people. A leak from an upstairs unit can damage two or three homes below it, and responsibility for the building structure, the unit interior and the tenant's belongings is usually split between the owner or association, the unit owner and the renter.

If you rent, tell your landlord or property manager right away, in writing as well as by phone, and photograph the damage. Your landlord's policy generally covers the building, but your own belongings are covered only if you have renters insurance. If you own a condo, check the association's rules and master policy as well as your own unit policy.

Whoever arranges the cleanup, the work itself is the same: stop the water, extract it, dry the structure and confirm it is dry before anything is closed up. Coordinating early with neighbours and management keeps the drying from being interrupted.