Facing yesterday’s storm today

A commentary by Amy Echols, Public Affairs Office, and Julie Ammann, Engineering and Construction Division

Flooding devastates Oregon in 1964. (Corps of Engineers photo)

Flooding devastates Oregon in 1964. (Corps of Engineers photo)

Frozen ground and heavy snow collided with torrential rainfall and increased temperatures in December 1964 to wipe holiday shopping and family gatherings off the calendar. The generations of Oregonians who lived through the flood came to a hard-won understanding of the consequences of living in vulnerable areas and the power of a Pacific Northwest “atmospheric river,” locally known as a Pineapple Express. The generations that followed, and newcomers to the state, remain free of the harrowing memories but still face flood risks for some of the same, and some evolving, reasons.

Where the rain fell in the past is no guarantee of where it will fall in the future. Technical information from 1964 and other floods consistently indicate that flooding is often the result of concentrated rain inundating one area while a tributary basin “just over the ridge” may be spared heavy rainfall. The eye of the storm can shift like the weather.

While the weather conditions leading to the historic 1964 Christmas flood and the more recent 1996 flood were extraordinary, those same conditions in our more urbanized state today could result in river levels exceeding those in 1964. Watershed conditions have changed around the state to meet urban and updated agricultural needs. Large areas of historic floodplains no longer function in their natural form. They are now housing developments, roads, parking lots, rooftops and other impermeable surfaces that alter drainage patterns and force flows into unsuspecting communities.

So while the Corps’ storage dams and state and localized actions have reduced risks for some populations downstream, a growing population and newer development remain in harm’s way. Not all our actions, not all of our agencies together, can eliminate risk. The conditions of our land and the forces of the sky together play roulette with our future.

Planning and technology on our side

With modern forecasting and weather technology, experts can better detect a storm of 1964’s magnitude and duration days in advance. Watches and warnings through radio, internet and television will alert citizens of the approaching risk. Emergency management and first responders will pull in resources from across the country in advance. Shelters will await citizens evacuating from low-lying areas.

Vast areas of agricultural land around Oregon were developed for residential use after 1964 as population increased. The Federal Emergency Management Agency designated the shaded land on this map as vulnerable to certain levels of floods. Regulations require that homeowners with federally-backed home loans in these areas purchase flood insurance. The Willamette River is bottom right. (Image source: Oregon Department of Land Conservation and Development)

Vast areas of agricultural land around Oregon were developed for residential use after 1964 as population increased. The Federal Emergency Management Agency designated the shaded land on this map as vulnerable to certain levels of floods. Regulations require that homeowners with federally-backed home loans in these areas purchase flood insurance. The Willamette River is bottom right. (Image source: Oregon Department of Land Conservation and Development)

Improvements in floodplain conservation, flood warning systems, emergency response and recovery programs will greatly reduce the consequences. Programs, at the local, state and national levels now assist communities before, during and after natural disasters. And we have a clearer understanding of the combination of factors that create flood risks. The most notable difference between those days and now would be dramatic reduction in loss of life.

Today, the national approach for reducing risk is to share responsibility across government, community and individual levels. This approach can only be effective if individuals – in their roles within communities, households and businesses – have access to and use technical information. As individuals, we should understand the likelihood and consequences of flooding where we live. Consideration for the effectiveness of risk reduction actions and the limits of pre- and post-flood assistance allows us to make the best decisions and may provide incentives to take on preparedness actions.

Without this preparation – and once a Pineapple Express moves in – there is far less that can be done to prevent many of the same consequences Oregon has already experienced.

There is a drier (and more hopeful) side, as many local agencies advance their own hazard reduction investments and increase their attention to the relationship between land use and flood risk. The Corps, for its part, has taken big steps in the last decade to improve risk communication by sharing information and hosting collaboration.

As members of Oregon’s current generations, as descendants of witnesses to 1964 or newcomers, we can reflect on our own vulnerabilities (such as life safety or economics) and consider all information available today. We should accept the challenge of preparing for the conditions around us and take action and make choices that better resist what nature will throw at us in the future.

Infographic: Corps of Engineers

Infographic: Corps of Engineers

 

 

 

 

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