Beginning on December 1, 1975, one of the worst floods in Snohomish County's history strikes. A combination of rain and melting snow in the mountains cause several Snohomish County rivers to flood, with the worst flooding along the Snohomish River. The Snohomish River reaches a record depth of 33.16 feet at Snohomish, and the Snohomish Valley bears the brunt of the six-day flood, with a 50,000-acre "lake" forming in the valley that stretches between Everett and Monroe. Damage runs into the millions of dollars; much of the loss is attributed to the failure of a dike and pumping plant at French Slough, just southeast of Snohomish. No human lives are lost, but livestock losses are severe, with an estimated 3,500 head of cattle and other livestock dead as a result of the flood.
Just Another Flood
It began as a typical late autumn flood in Snohomish County -- snow in the mountains as the 1975 Thanksgiving holiday weekend ended, followed by a sudden warm up and rain that melted the snow and pushed rivers out of their banks. On Monday, December 1, the first reports of flooding began coming in. As dawn approached on Tuesday, December 2, the situation grew more serious as the Skykomish and Sultan rivers in Sultan topped their banks and rose rapidly. Some Sultan residents spent the day frantically sandbagging their homes and the town’s storefronts as the water continued to rise; others paddled canoes along the streets of downtown Sultan in water from two to five feet deep. But by nightfall the flooding in Sultan seemed to be abating, and though forecasts called for more flooding, no one anticipated what was coming.
West of Sultan, the Snohomish River also rose above flood stage -- but residents of the Snohomish Valley were more sanguine about the prospects of flooding along this river. They had the French Slough (also called French Creek) Flood Control station, a dike and pumping facility located about a mile upriver from the city of Snohomish, to protect the valley. The station was built in 1963 and 1964 to provide a buffer against flooding that had plagued thousands of acres of prime farmland almost annually, and to provide faster draining for the valley if it did flood. The station’s six pumps were capable of pumping a total of 300,000 gallons a minute, but, commented the Everett Herald in a casual premonition on December 3, “This week’s flooding will be the first major test of the effectiveness of the French Slough outlet pumping structure east of Snohomish.” By the time the paper hit the streets on December 3rd, the flood had already destroyed the structure.
Broken Dikes and Drowned Cattle
About 10 p.m. on the night of the December 2, floodwaters tore a nearly 300-foot-wide hole in the French Slough dike, and water poured into the valley. The pumping station at the facility was quickly overwhelmed and failed. Floodwaters raced throughout the valley, rising so fast that people who had been outdoors laying sandbags had little time to do anything except run. Soon a 50,000-acre “lake” stretched between Everett and Monroe, with stranded cattle left standing atop dikes or other spots of high ground in water that in some places came up to their necks.
On Wednesday, December 3, more dikes along the river failed, overwhelming sandbaggers. On Wednesday night dikes near the Jackknife Bridge on the south end of Ebey Island (east of Everett) failed, forcing residents from their homes; parts of the island were soon under 15 feet of water. By this time the flooding was so extreme that there was little more that could be done. Commented Bob Hamlin, the coordinator for the Snohomish County Department of Emergency Services, “There’s nothing left to dike. You can only put so much water in the glass” (Everett Herald, December 4, 1975, p. 2-A).
A total of about 330 people in Snohomish County were evacuated from their homes -- by helicopter, boat, and truck -- as the floodwaters rose. Emergency centers were set up, the local population pitched in, and the Red Cross and Salvation Army stepped in too. Most evacuees stayed with friends and relatives until they could return home.
Catastrophic for Cattle
But the most catastrophic damage that resulted from the flood -- and what made this flood especially memorable when contrasted with the numerous floods that swept Snohomish County in the twentieth century -- was the loss of livestock, particularly cattle. About 3,500 head of cattle and other livestock were lost throughout the county, with most of the losses resulting from the failure of the pumping station at French Slough. Five dairy farmers with farms near the station bore the brunt of the losses, losing nearly 1,500 head of cattle just between them. These cows didn’t all drown, at least not initially. Many died from exhaustion from standing in cold floodwaters for several days.
As the flood retreated late in the week, the problem arose of how to dispose of the dead animals. Early the next week, a disposal site was finally found -- the Bryant landfill about three miles north of Arlington. The National Guard assigned two units the enormous task of disposing of the decomposing animal carcasses. “Operation Cow,” as it was called, proved to be a macabre spectacle, attracting sightseers from miles around to the landfill to watch the cattle being buried in enormous 50-by-100 foot trenches 12 feet deep.
The Flood Recedes
The flood peaked during the day on Thursday, December 4. The Snohomish River at Snohomish reached a record depth of 33.16 feet, more than eight feet above flood stage. By the end of the day on Thursday as many as 40 dikes along the river had collapsed from the flood. But finally the weather began to turn, and by early Friday, cooler, drier weather had moved in. The river began dropping, though it remained above flood stage at Snohomish until Sunday, December 7. Ironically, remnants of the dikes that had failed during the flood prevented proper drainage of the floodwaters as the flood receded. Some fields remained flooded, in a few places up to 10 feet deep, for several more weeks.
Half a million sandbags were used in the nearly weeklong water war. Damage estimates ranged widely, from $8 million to $50 million, with perhaps 300 homes damaged. But, aside from the extensive property damage and near-catastrophic loss of livestock, there was one pleasant surprise: No one was killed or even seriously injured.
The French Slough Flood Control station was rebuilt -- and damaged once again by flooding in November 1995 and February 1996.