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If you travel outside of the Pacific Northwest and tell someone you’re from Portland, chances are you’re going to hear a comment about rain. People who have never set foot in Oregon often have the impression that life here exists under one steady downpour. Few people outside the Pacific Northwest call to mind our sun-bathed, bone-dry summer months when they think of Portland. It can take some explaining to point out that, even in our wettest months, the rain is usually nothing more than a passing shower.
Though the extent of the rain may largely be a stereotype about the region, we are prone to the occasional flooding event. This past Halloween, torrential rainfall from a passing storm combined with clogged drains to create flash flood conditions on Portland streets. In December, the surrounding region was so battered by rain and ensuing floods that Governor Kate Brown declared a state of emergency in 13 counties. Homes were evacuated in nearby Vernonia and St. Helens, and over 100 families were evacuated from a S.E. Portland apartment complex due to approaching flood waters. The flooding also caused significant MAX delays, along with hazardous mudslides and sinkholes, which closed down roadways. In fact, Portland saw its wettest December on record last year, with over 15 inches of rain falling in total.
When it comes to flooding, staying safe is first and foremost. Even when life and limb aren’t on the line, flooding can also create a potential for property damage or indirect hazards and health risks if not handled appropriately. But before we get to the nitty-gritty of what you need to know in the event of an encroaching flood, let’s take a look back at three of the worst flood events in Portland history.
Willamette Valley Flood of 1996
When most people think about flooding, they point to heavy rainfall as the primary culprit. Portland’s extensive flooding during the winter of 1996 proved how it’s most often a conflux of inauspicious circumstances that causes the most damage. Sustained heavy rain during January 1996 raised river levels and saturated soil. A heavy snowstorm in the surrounding area soon complicated matters when it was followed by a warm subtropical jet stream in early February that caused a rapid snowmelt. Before long, major rivers were overflowing.
The Willamette River flooded the east bank, damaging businesses and homes. The swelling river threatened to breach the seawall at Tom McCall Waterfront Park and flood into downtown, which would’ve wreaked even more havoc. Portland mayor Vera Katz even called upon civilians and city workers alike to help construct a plywood, plastic and sandbag wall between the Steel and Hawthorne Bridges in a last ditch effort to protect against rising waters. Thankfully, flood waters crested just inches short of the seawall, and the makeshift “Vera’s Wall” wasn’t tasked with such a burden. Elsewhere, flooding engulfed homes between Milwaukie and Gladstone. Oregon City’s downtown was hit hard, and rising waters created a crisis as far west as the coast, hammering Tillamook in the process. During a several-day span, eight Oregonians lost their lives and over $500 million of property damage was done to the region, including drowned livestock and swept-away homes. Portland received over seven inches of rain in those first days of February, with some reports claiming surrounding regions experienced nearly a foot of precipitation.
All told, 26 Oregon rivers reached flood stages, causing evacuations of almost 22,000 people throughout the Pacific Northwest. Over 6,000 sought shelter from the Red Cross. More than 100 mudslides occurred in the Portland metro area leading to $27 million in highway damage between Portland and Salem. The Army Corps of Engineers dispensed over 660,000 sandbags to the area. Perhaps the most frightening aspect of the flood is that were it not for the successful manipulation of tributary dams built in the Willamette River Basin in the 1930s, the Willamette River’s level would’ve reached an estimated two feet higher, which would’ve caused some $1.1 billion in damage, including possible destruction to the city’s many bridges.
Christmas Flood of 1964
As bad as the 1996 Willamette flood was, it didn’t hit the high-water mark set by the devastation wrought in Oregon and California by the Christmas Flood of 1964. Once again, heavy snowfall followed by a storm from a warmer weather front prompted the disaster. As temperatures rose, rain fell and snow melted, the ground underneath remained impenetrable from a prior deep freeze. The Willamette swelled and tremendous mudslides plagued the Mount Hood Corridor. In Oregon, 17 people lost their lives from drowning, electrocution and a bridge collapse in John Day. Damage totaled in the hundreds of millions of dollars, with over 150,000 acres of flooding caused by the Willamette alone. The Steel Bridge’s lower deck was entirely submerged and the Hawthorne Bridge sustained so much damage from a floating mass of logs that it remained closed for a year.
Vanport Destruction of 1948
With shipbuilding becoming an especially important enterprise during World War II, public housing was quickly developed in the early 1940s to accommodate the influx of workers at the Kaiser Shipyards. Located north of the city, between Vancouver and Portland, the city of Vanport rose in population to some 40,000 people, making it Oregon’s second largest city for a brief period before the war’s end. Built in reclaimed lowlands along the Columbia River, Vanport was known to be at risk of flooding, and as heavy rains fell in May 1948, residents were cautioned about the probability of some flooding and encouraged to move valuable possessions to upper floors of their homes. Little did they know what kind of damage was in store.
The heavy rain joined forces with melting snowpacks to drastically swell the Columbia River. On May 30, 1948, a large section of the dike holding back the Columbia collapsed. Surging waters poured into the low-lying Vanport, permanently destroying the city as homes and businesses were set adrift. Thankfully, a combination of circumstances kept the fatality count relatively low. Following World War II, Vanport’s population had reduced by over half. The fact that the flood occurred on Memorial Day meant fewer residents were in their homes at the time, and a slight advance warning after the initial breach helped in preventing a greater loss of life. Still, the destruction of Vanport uprooted thousands of families and cost 15 people their lives.
What to Know About Flooding
Fortunately, this type of massive destruction from flooding is rare. However, as last fall’s heavy rains taught us, even smaller-scale flooding can create significant hazards. With a little bit of knowledge, you can greatly reduce your family’s chances of being harmed by flood damage.
One of the most obvious causes of localized flooding is blocked storm drains. Also known as catch basins, storm drains filter water from the streets to the sewer system, and if they become clogged they can create ponds of standing water in the streets and potentially cause damage to homes. Keeping drains clear is a crucial step in preventing flooding around your home. City officials recommend using a rake or pitchfork to clean away debris from the top of a catch basin prior to an impending storm. The grates themselves should never be removed, but if water is pooling around a drain in the midst of a rainstorm, clearing away debris from the top of the grate will likely help restore drainage. If the drain remains clogged, residents can call 503-823-1700 to report the problem to the city. Portland also offers free sand and sandbags to residents (though you must provide your own shovel) at three different locations around town: S.E. 88th Ave. and Holgate; S.E. 111th Ave. and Harold; and S.W. 42nd Ave. and Vermont.
Should your home fall victim to flooding, the top priority is ensuring whether it’s safe to remain there. Electrical hazards are of primary concern, and you should not turn on any electrical appliances until it is determined they have remained dry. You should also evaluate any “slip and fall” hazards and be careful when lifting any saturated items, as they can be extremely heavy when waterlogged. These types of indirect dangers often can cause more harm than the floodwater itself. If your home does experience flooding, remove excess water by mopping or blotting. Do not use a standard vacuum cleaner. Place foil or wooden blocks between legs of furniture and wet carpet. Colorful rugs should be removed from wet carpeting to prevent staining. Fans and dehumidifiers can help dry out floors to reduce the risk of mold and mildew.
Backed up water from a flood can carry with it bacteria, pesticides, animal waste and chemicals, so it’s important to avoid contact with contaminated materials. When cleaning up water-damaged areas, wear rubber gloves if possible. If entering a building affected by a flood, be sure to keep an eye out for structural damage such as warped ceilings. While washable items can be salvaged, any food or hygiene products that come in contact with flood water should be discarded.
Of course, the primary danger from floods comes from travel. During inclement weather, drivers are encouraged to look at ODOT’s online TripCheck cameras to ensure that their route is free of flooding, road closures or mudslides. If you are forced to drive during a rainstorm, be sure to pack appropriately warm and/or waterproof clothing in the event of an emergency. Reduce speed and drive cautiously. Do not drive through flooded streets or bypass any barricades. To avoid hydroplaning, tires should be kept properly inflated with their treads in good working condition. Following in the tracks of a car in front of you is another good strategy to ensure appropriate traction. Finally, make sure to turn on your headlights to make your vehicle more visible to other drivers.
By being prepared you can greatly reduce the risk caused by heavy rainfall. When it rains, it doesn’t always pour in Oregon. But when it pours, a little preparation goes a long way.