US Army Corps of Engineers
Northwestern Division Website

Containing the Flood of 1996

From "Currents of Change"

Portland District, U.S. Army Corps of Engineers
Published Feb. 1, 2021
A McDonalds sign shows the magnitude of the flooding in some parts of Oregon during the Flood of 1996.

A McDonalds sign shows the magnitude of the flooding in some parts of Oregon during the Flood of 1996.

The Oregonian recognized the Corps' efforts to save the downtown Portland area from the flooding.

The Oregonian recognized the Corps' efforts to save the downtown Portland area from the flooding.

Editor's note: "Currents of Change" is A History of the Portland District, U. S. Army Corps of Engineers, 1980-2000, which Portland District produced in 2003.

As with volcanic eruptions and other natural events, the Corps responded to flooding as part of its disaster relief work. One of the biggest floods the Portland District faced in the late 20th century occurred in February 1996 and caused millions of dollars in damage to the region. The District played a crucial role in combating this flood's impact through a variety of short-term and long-term activities. Once the immediate danger had subsided, the flood prompted environmentalists, concerned citizens, and government agencies to reexamine how human development patterns, such as logging and agriculture, contributed to the intensity of flooding.

The Pacific Northwest has a history of flooding. Winters in the region sometimes bring a sudden influx of warm westerly winds, referred to locally as chinooks, which rapidly melt the snow pack, causing runoff over the still frozen ground. The first snowmelt, which is often accompanied by warm rain, swells tributaries and major rivers, resulting in floods of various intensities. In the late 19th and early 20th centuries a series of floods transpired on the Willamette and Columbia rivers. More recently, major floods struck western Oregon in 1948 and 1964. Thirty-two years later, another flood of similar intensity struck the region.100

The flood of 1996 began in much the same way as previous floods. In the months prior to February, record snowfall had been accumulating, saturating the soil. In January, the snowfall doubled and tripled the snow pack in some locations. Then in early February, a storm began near Java in the western Pacific. This "pineapple express" storm gathered moisture and power as it raced across the subtropical Pacific and veered northward. Typically such storms struck California, but because of La Nina, a powerful west­ east jet stream, the storm worked its way northward, across Washington and Oregon. The storm's heavy rains mixed with the snow in the mountains; rainfall in some locations reached half an inch an hour.

From February fifth through the eighth, heavy rain fell on the Northwest. Combined with melted snow, the rain transformed streams into raging torrents and caused rivers to surge over their banks. "I've never seen anything like this before and I have been in Oregon for 25 years," said a resident of Oregon City. "Last night, the water had not reached the McDonald's parking lot. Now McDonald's looks like it's in the middle of the lake.'' Flooding hit communities from Puget Sound to central Oregon, killing four people and forcing thousands of others to evacuate. In the countryside, flooding destroyed winter wheat crops in southeastern Washington and damaged many farms and ranches. At least 1,000 dairy cows drowned in Tillamook County, and two farmers lost their entire herds. Rising water and mudslides - more than 100 in the Portland area alone - shut down transportation networks and isolated some towns. Interstate 5 - the north-south artery across Oregon and Washington - was cut off in two places, buried under a landslide and several hundred feet of water. Freight trains in eastern Oregon were backed up, unable to cross through the Columbia Gorge, where a massive slide had buried the railroad tracks and most lanes of the interstate.

"This is a very, very damaging flood," Washington Governor Mike Lowry told reporters. “It is way too early to make assessments, but I've seen numerous comments that this might be the worst in 50 years." At the national level, President Clinton issued a federal disaster declaration, clearing the way for providing temporary housing, family grants, and low­ interest loans for flood victims.102

The Corps took a number of immediate steps to lessen the flood's impact. Before the rain intensified in early February, the Corps had been releasing water from its hydro projects to make room for spring runoff. Once the heavy rains began, it immediately started cutting back flows and storing water in its storage projects. Engineers and technicians at the North Pacific Division Reservoir Control Center (RCC) in Portland worked around the clock to manipulate more than 60 dams in the Columbia River system to minimize flooding. Managino river flows during the flood was a delicate balancing act, according to Cindy Henriksen, Chief of the RCC. "There is a complex system of dams on Northwest rivers and streams," she explained. "But not all of these dams are designed for flood control. Only one darn on the lower Columbia the John Day, has significant storage capacity." 103

Despite the challenges in regulating water flow, Corps dams were successful in holding back the flow of water and reducing flooding. Perhaps their most visible success was in downtown Portland, which, because of its location at the confluence of the Columbia and the Willamette, was especially vulnerable. A number of uncontrolled tributaries entered the Willamette upstream of the city, and many experts predicted that the crest would top Portland 's floodwall, which protected the downtown area. In response to this threat, Portland's mayor Vera Katz requested technical assistance from the Corps and asked for volunteers to help city crews reinforce the wall. In a matter of hours, the riverfront teemed with people filling sandbags, building a higher plywood wall, and reinforcing the plywood with concrete roads.104

"You essentially had this mature levee built all along the seawall," explained Jerry Christensen.105 Crews worked into the night as the river edged up the wall, lapping over it at times. When the crest finally arrived, it was longer than predicted due to waning rainfall, and the city was spared major flooding.  "It  could  have  been a terrible nightmare for Portland if those dams weren't there," said Tom Worden, spokesman for Oregon's state emergency management office.106 Mayor Katz was also grateful, calling the effort by the Corps and volunteers "a heroic, heroic public works project." The Oregonian applauded the District as well, summarizing the effort in a dramatic headline reading, "How They Saved Downtown."108

The Corps contributed to the flood relief efforts in other ways as well. At The Dalles-John Day project, for example, the agency distributed more than 100,000 sandbags to outlying communities in four counties. At Mill Creek, Corps' personnel worked to keep the rising waters at bay. When debris began backing up the creek on February 7, crews worked until midnight for many consecutive nights to clear the material. "They were great," exclaimed Kim Fisher of The Dalles Chamber of Commerce. "The guys worked very hard and were soaked from the rain." In addition to directly battling the flood, the Corps also provided less traditional assistance. At the Bonneville project, for example, the District allowed 11 students from a nearby school to use the second powerhouse visitor's theater as a makeshift classroom after a mudslide threatened their own facility.

"They're on the project from 8 a.m. until 2 p.m. and we've reserved the gymnasium in the project auditorium for their physical education classes," explained Jim Runkles, park manager.109

When the initial threat of flooding was over, the District shifted to recovery work. The agency's primary work involved repairing both federal and non­-federal dikes, levees, and flood protection embankments in numerous counties throughout the region. The floods also had produced heavy shoaling in the Columbia River navigation channel, prompting the Essayons and its crew to undertake dredging work. Through its immediate response and longer­ term efforts, the Corps substantially reduced the economic impact of the flood. Altogether, Corps projects in the Pacific Northwest prevented flood damages totaling more than $3.2 billion, with savings of $1.l million at Portland.110 

In addition to impacting human communities, the February floods also affected salmon populations in the Northwest. Raging river currents swept away banks, took out trees, and destroyed streamside vegetation; clear waters became choked with debris. The floods, however, also benefited fish populations by forming new side channels, depositing protective woody debris, scouring out pools, and bringing in new clean gravel. To the general public, the flood was a catastrophe, but for fish and other aquatic species, floods are a part of nature's cycle.

"These fish have lived with flooding for thousands, even millions of years, and they've done quite well without us," explained Stan Gregory, a professor at Oregon State University. Dave Heller compared floods to forest fires, another natural phenomenon whose role in promoting healthy ecosystems has historically been unappreciated.

"Floods are analogous to fire in a forest: It may not be pretty, but it surely plays a critical role," he said.

In fact, while "postcard-perfect, uncluttered streams'' are visually appealing, they offer little food and shelter for fish. By depositing woody debris and creating new deep pools and gravel bars, the floods actually improved the habitat of some streams.111

The impact of the 1996 floods on salmon streams was uneven: some suffered extreme damage, while others appeared to be recovering well and even prospering. Some of the disparity could be attributed to differences in terrain and local storm intensity, but the primary factor was the extent of human influences on the landscape. Scientists generally found that areas that were heavily altered by human development suffered more than those that were relatively untouched. Logging, for example, created clearcuts and logging roads, both of which increased the rate of slides. Agricultural development converted wetlands and floodplains, reducing a river's natural flood control system.112

The Corps, through its attempts to provide navigation, also contributed to the problem of flooding. In the Willamette River watershed, for example, the agency cut off secondary channels with debris dams, filled in sloughs to increase water volume in the main channel, and performed clearing and snagging activities. Over time, these activities transformed the historic multiple channel configuration of the river to a simplified single channel system that could no longer handle the same volume of water - particularly in an area that had become heavily urbanized.113

Prompted by the February flood and several others that followed it, environmentalists, scientists, and government officials in the Pacific Northwest questioned traditional land use practices, seeking a variety of solutions to lessen the impacts of flooding. Despite their success in controlling the water flow, few believed it was feasible or desirable to build new dams. Instead, they pushed to revamp and better enforce land use policies to limit development in flood zones, restrict clear-cutting of forests on steep slopes, and restore wetland areas. "We need long-term changes in policies over the next 40 years," said John Baldwin, a University of Oregon professor and specialist on environmental public policy. "We have to realize that we're looking at problems that building one dam on a river won't change. We need to change the whole way we do business." Later he added, "What we really need to do is develop human systems that recognize the primacy of physical systems." Environmentalists and scientists joined in the debate, arguing for a moratorium on steep-slope logging on both private and public lands until other forest practices could be enacted to reduce the number of landslides. Some environmentalists supported returning the Willamette River to a more "natural" state. "The main thing we can do to alleviate flooding in this valley is to give the flood plain back to the river, to give it room to roam and stay out of its way as best we can," said Phil Wallin of River Networks, a national river conservation group.114

In a further step toward river restoration, River Networks proposed restoring flood plain functions through a voluntary wetlands restoration program along the Willamette. The group, who had been exploring the idea prior to the Flood of 1996, released its preliminary report during the February flooding. The River Networks report, along with the support of Congressman Peter DeFazio, led Congress to authorize the Portland District to study the issue. After obtaining study authority, the Corps completed a reconnaissance study and proceeded to begin work on the feasibility study.115

The Corps expects the feasibility study, which generally takes two to three years, to be completed in the early 21st century. The major challenge facing the District at this stage is finding a local sponsor to satisfy the cost-sharing requirements of the project. Identifying an appropriate sponsor will be difficult given the considerable costs of the project, but the Corps remains optimistic about the benefits of this type of voluntary restoration work. "It's clear that the Corps needs to look at new options for flood control in the Willamette Basin,'' remarked Project Manager Matt Rea. Furthermore, Rea believed that the voluntary nature of the program heightened its potential for success. Much of the land along the Willamette River is privately owned and divided into small parcels. Attempting to implement a mandatory program would likely meet with a great deal of resistance from private landowners, whereas a voluntary program, including tax incentives, easements, and other real estate agreements, would be less politically volatile. 6

The February 1996 flood brought extensive damages to communities throughout the Pacific Northwest. Using its ability to quickly mobilize, its technical expertise, and its intricate systems of dams, the Corps contributed greatly to relief efforts by lessening the impacts of the flood. The agency's hard work did not go unnoticed; after reviewing flood damages President Clinton stated that he was "very impressed with ... the work the Corps of Engineers has done to try to get the water down as much as possible, as quickly as possible."117 More formal recognition was given in February of 1997, on the one-year anniversary of the flood, when Vice President Gore presented his National Performance Review Hammer Award to the Portland District and the North Pacific Division. The Bonneville Power Administration, Bureau of Reclamation, and City of Portland also received Hammer Awards, which are given to teams of federal, state, and local employees and citizens working together to build a better governrnent.118

Yet the story of the flood extended beyond the immediate crisis, prompting environmentalists, scientists, and concerned citizens in the region to reexamine land use practices and beliefs. Logging its position, looking beyond dams to other non-structural approaches to flood control.'' The Corps has changed the way it approaches the environment," said Robert Willis, Chief, Environmental Resources Branch. "We used to focus only on flood control and navigation work. Now our emphasis has shifted to include ecosystem restoration and fish and wildlife management."119