Quick answer
In mid-November 2021 an atmospheric river sent the Nooksack and Skagit rivers to record or near-record levels, flooding Sumas, Everson and Nooksack and prompting evacuations in Skagit County. Water systems stayed pressurized, but some sewers backed up. After floods, treat water as contaminated, follow boil advisories, and have submerged gas and electric equipment checked.
What happened
An atmospheric river brought heavy rain to the Pacific Northwest from Saturday, November 13, to Monday, November 15, 2021, according to the Associated Press. Bellingham received about 5.57 inches over those days, the AP reported, compared with a normal total of 5.2 inches for the entire month of November. Whatcom County put an emergency declaration in place on Sunday, November 14, and Governor Jay Inslee declared a severe weather state of emergency in 14 counties on Monday, November 15.
Fox Weather, citing the National Weather Service, reported that by Monday afternoon three rivers had reached record flood heights. The Nooksack River broke its 2006 record of 149.6 feet, and the Samish River near Burlington also set a record. Cascadia Daily News later reported a Nooksack crest of 150.35 feet on November 16.
Sumas, Everson and Nooksack
Cascadia Daily News reported that the first flood began on November 14, with the Everson mayor sandbagging in Everson and Nooksack that night as the water rose quickly. Fox Weather reported that by Monday morning the road in Sumas was closed to the Canadian border and sheriff's deputies were rescuing trapped residents in Everson. The AP reported that flooding hit an estimated three-quarters of Sumas homes and that about 500 rescues and evacuations were reported in the area.
The Northern Light, a Blaine newspaper, reported that city officials said 75 percent of Sumas homes had water damage on Monday and most of the roughly 1,600 residents evacuated. A year later Cascadia Daily News put the figure at more than 85 percent of structures damaged. The paper reported that, at the one-year mark, more than 1,000 homes and businesses were damaged, recovery costs topped $150 million, one person had died, and many homes lacked flood insurance. A second flood followed on November 28.
Skagit County
Skagit County's river update issued early on November 16 recommended evacuation for Fir Island, Sterling and West Mount Vernon. Late on November 15 the Skagit River at Concrete was holding at 37.24 feet, and the county forecast a crest of 37.61 feet at Mount Vernon, where the flood wall was built to hold water up to 38 feet. Mount Vernon closed the Division Street bridge to all but emergency traffic. Fox Weather also reported that officials urged residents of Hamilton to evacuate.
The La Conner Weekly News, citing the U.S. Geological Survey, reported the river at Mount Vernon crested at 36.7 feet at 5:17 a.m. on Tuesday, November 16. The county figure was a forecast and the newspaper's was a measured reading, so the numbers differ slightly. The city declared a civil emergency on Monday and the Red Cross opened shelters.
Water and sewer systems
The Washington State Department of Health published a fact sheet on how Sumas, Everson and Nooksack water and wastewater operators responded. The sheet, published in October 2022, says Sumas flooded and its backup system had problems, leaving Everson's sources as the only ones still producing water in the region. Everson opened a bypass valve on an emergency connection so it could supply Nooksack. All seven systems stayed pressurized throughout, which helps keep contaminants out of water lines. Operators worked 36 hours without going home. The department listed a generator upgrade at Sumas, remote monitoring and more reservoir storage among future needs.
Sewers did not fare as well everywhere. The Northern Light reported that the Birch Bay Water and Sewer District received 4.7 million gallons at its sewer treatment facility on Monday, nearly double its previous daily record of 2.7 million set in 2010, and that sewage backed up into 17 homes. In Blaine, wastewater treatment returned to normal on Tuesday after discharge leaked outside the facility because of high water intake. We did not find a boil-water advisory for these systems in the sources we reviewed.
What floodwater does to household plumbing
The U.S. Environmental Protection Agency says floodwater may carry raw sewage and hazardous substances, and it advises avoiding direct contact and washing hands often. It also says to check with your drinking water utility or health department about whether a boil-water advisory is in place, and to boil water for a full minute when told to.
If sewage has backed up into a home, the Centers for Disease Control and Prevention advises wearing rubber boots and waterproof gloves, discarding materials that cannot be disinfected such as drywall, rugs and cloth, and cleaning hard surfaces with soap and water followed by a bleach solution of 1 cup per 5 gallons of water. The EPA adds that households with septic systems should not use them until the water in the soil absorption field drops below the water level around the house.
Water heaters, gas and electrical equipment
The Gas Appliance Manufacturers Association (GAMA) warned, in a report carried by ACHR News, that gas and oil control valves must be replaced once submerged, even if the unit seems to work, and that work on flooded equipment should be done by a qualified, licensed contractor. It cited a homeowner who was badly burned relighting a flooded water heater pilot.
The CDC's flood recovery fact sheet adds that natural gas should stay off until it is safe, that electrical equipment must be completely dry before use, and that anyone who smells gas should leave and notify the gas company or fire department. The EPA says never to run a generator inside a home, garage or crawlspace.
When to call Pyper Plumbing
If a flood or heavy rain has left sewage coming up through floor drains, toilets or tubs, or you see new leaks, low pressure or a water heater that was underwater, call. Pyper Plumbing handles emergency repair, sewer line repair, water heaters and leak detection in Snohomish, Skagit, Whatcom and Island counties. Check with your utility or health department about advisories first, and leave the house and call 911 or the gas utility if you smell gas.
Common questions
Was there a boil-water advisory for Sumas in November 2021?
None appeared in the sources we reviewed. The Washington State Department of Health fact sheet says all seven regional water systems stayed pressurized, but residents should confirm current guidance with their utility.
Can I reuse a water heater that was flooded?
The Gas Appliance Manufacturers Association says submerged gas or oil control valves must be replaced and that flooded equipment should be handled by a qualified licensed contractor rather than a homeowner.
What should I do if sewage backs up into my house?
The CDC advises wearing rubber boots and waterproof gloves, discarding items that cannot be disinfected, and disinfecting hard surfaces. Avoid using fixtures that are backing up until the problem is addressed.
Sources
Facts in this guide come from the following references. Local rules and manufacturer instructions can differ, so follow your utility and your equipment manual.
- Associated Press via WJLA, US-Canada border towns assess damage from devastating floods (November 17, 2021)
- Fox Weather, Photos, video show damaging floods in Western Washington
- Cascadia Daily News, All hell broke loose: one year post flooding in Whatcom County (November 16, 2022)
- The Northern Light, County crews grapple with devastating flood
- Skagit County, River level update (November 16, 2021)
- La Conner Weekly News, Near-record Skagit River flood stage in Mount Vernon (November 17, 2021)
- Washington State Department of Health, Sumas Nooksack flooding and response (Fact Sheet 331-701)
- U.S. EPA, Flood
- CDC, Key facts about flood recovery (2004)
- ACHR News, GAMA issues warning about flooded equipment
This guide is general information, not a substitute for an on-site inspection. If you smell natural gas, leave the building and call 911 or your gas utility. Pyper does not perform gas line work.
