Flooding is on our mind this week in regards to the flash 500-year flood that has swallowed a large chunk of southern Louisiana. While the sun shines down on Portland for the sliver of the summer that remains, a federal emergency has been declared for the epic flooding that continues to devastate Baton Rouge. Historic flooding plagues the Gulf Coast state, with some areas seeing 30 or more inches of rain in a matter of just a few days. Over two feet of rainfall landed in just three days– more rain than Los Angeles has seen in four years.
Over just one weekend, thousands of houses and cars have been inundated, 20,000 residents have been displaced, 11,000 remain in shelters and are now homeless, and 7 have died. Scientists expect this type of event to occur more frequently as a result of climate change. As Earth’s atmosphere warms, its ability to retain water vapor increases, leading to an increase in isolated spurts of heavy rainfall.
Willamette River Flooding
View south from the Broadway Bridge on Feb. 10, 1996, at the peak of the Willamette River flooding. Photo by Steve Morgan.
Such terrible flooding brings to mind some of Portland’s historic floods in years past. Portland is home to the Willamette River, which is prone to annual flooding. The Louisiana flood bears a striking resemblance to the Willamette Valley Flood of 1996 that spanned from Oregon City to Corvallis, swallowing homes, businesses, livestock, and people’s livelihoods. At the time, President Clinton declared a state of emergency for 18 Oregon counties. Like the Louisiana flood, no one saw the Great Flood of ‘96 coming. Several unique weather patterns contributed:
- Unusually heavy rainfall permeated the ground and elevated rivers in January
- Abundant and delayed mountain snowfall in January
- A deep freeze in Willamette Valley that lasted for a week
- A warm jetstream that thawed the late snow, bringing heavy rainfall, or “pineapple express.” Such events often lead to major snow-melt flooding as warm rains land on frozen and snow-cloaked ground.
Within hours of the deluge, every major body of water in the Willamette valley region flooded. According to hydrologist Andy Bryant with the National Weather Service, “You can get pretty major flooding just from heavy rainfall. Even with the 1996 flood, 70 to 80% was due to heavy rain with the snow melt.” This was also the case in the Christmas Flood of ‘64 that wreaked havoc throughout Northern California and the Pacific Northwest.
The Christmas Flood occurred between December 18, 1964 and January 7, 1965 spanning 152,789 acres of land and killing 17 Oregonians. The National Weather Service declared it the 5th most destructive weather event in the state in all of the 20th century. It killed 4,000 head of livestock and caused millions of dollars worth of damage.
The Willamette Valley Flood of 1996
2016 marks the 20-year anniversary of the Great Flood of 1996, a flood that brought over 7” of rain from February 1st to 13th compared to Portland’s average 5.35 inches for the entire month. Over 21,000 people were evacuated, and 8 were killed. 10,089 homes were damaged in Oregon and 3 surrounding states, 760 heads of cattle were lost, and over 100 mudslides occurred in Portland. The flood caused $27 million in highway damage and nearly drowned Willamette Falls.
Such a flood in the Willamette Valley is not a matter of if, but when, it will happen again. More recently, Portland experienced a massive flood just last year. December 7, 2015 went on record as the “wettest day in Portland history.” Oregon Governor Kate Brown issued a State of Emergency for 13 counties after a series of severe storms. Several abandoned their cars on the road as landslides and flooding plagued the streets.
Hydroplaning
Standing water is dangerous if you are trying to get around. Flooding conceals potholes and forms a barrier between your tires and the road, causing loss of traction and control, leading to some of the ugliest car accidents in Portland each year. A few simple tips can help you avoid hydroplaning on days with heavy rain.
- Always check tire tread. This wicks water away from your tires allowing you to maintain control of your vehicle. You need at least 1/16th of an inch.
- Drive 30 MPH or slower
- Avoid slamming on the brakes and making sharp movements
- Drive in the tracks of the driver ahead of you
If you find yourself hydroplaning, be sure to do the following to recover:
- Take your foot off the gas
- Steer in the direction you want to go when traction is regained
- Don’t slam on your brakes. Apply brakes gently when you feel pavement again.
- Talk to a Portland personal injury attorney in the event of a collision by calling Rizk Law: 503-245-5677.
