The flooding and numerous mass wasting events were caused by a Pineapple Express, a type of atmospheric river, which brought heavy rain to parts of southern British Columbia and northwestern United States.

The Fraser Valley, which is heavily populated, is responsible for most of the agricultural production in the province, with limited ability to feed farm animals in the absence of rail service.

[7] The British Columbia Minister of Public Safety, Mike Farnworth, issued a statement that the military deployment ended on December 17 after a month of aid.

[4] Several weather systems in early November contributed to record rainfall in southwestern British Columbia and the Pacific Northwest region of the United States.

[10] Then the first deep low pressure system, which climatologists refer to as an atmospheric river, formed in the Pacific Ocean and moved into the coast on November 12.

[23] Via Rail passenger service on the Canadian, which uses CNR and CPR tracks, cancelled all trains travelling west of Winnipeg until December 12.

[26] Five days later, Duffey Lake Road was re-opened to restricted traffic[27] as ongoing search and rescue efforts led to three more people recovered as deceased.

[32] On November 18, the Government of British Columbia estimated that repairs for the Coquihalla Highway between Hope and Merritt would take months and that temporary Bailey bridges would be procured.

A track washout caused the derailment of a Canadian National Railway-operated freight train 25 kilometers north of Hope, British Columbia.

[36] On November 15, all 7,000 residents of Merritt were evacuated after the city's sewage treatment plant flooded and failed after the Coldwater River burst its banks.

On the north side of the Fraser River near Agassiz, Highway 7 was closed due to multiple mudslides that trapped over 300 people.

[44] The victims were airlifted to safety by 3 search and rescue helicopters from CFB Comox[45] after spending more than two nights trapped inside vehicles.

[46] Harbour Air offered special flights from Harrison Lake to Downtown Vancouver for evacuated residents who were unable to use Highway 7.

[47] Via Rail and Canadian National Railway operated an evacuation train from Hope to the Pacific Central Station in Vancouver.

[54] The Sumas Prairie area was placed under catastrophic flood warning by that evening, with a substantial loss of farm animals, including cattle and chickens, predicted.

In order to stop the ongoing flooding of the Sumas Prairie, and enable repair of the affected sections of the dike, the original plan called for contracting crews and the Canadian military to construct a temporary 2.5 km long levee along Highway 1 near No.

[58][59] On November 28, the Nooksack River overtopped after recent rain events, forcing the evacuations of 90 homes in Huntingdon Village.

British Columbia Highway 1—the only practical road connection over the Malahat summit—was closed on the morning of November 15 due to washouts and landslides.

[71] A single round trip cargo ferry service was also offered along the eastern coast of the Island between Duke Point and Swartz Bay on November 18.

[83] In the city of Sumas, on the south side of the Canadian border near Abbotsford, an estimated 85 percent of homes were damaged by flooding.

[95] Public concern over these extensive disruptions to the supply chain led to panic buying across the Lower Mainland[96][97][98] and the Okanagan.

[106] On November 17, an initial 120 Canadian Armed Forces soldiers from CFB Edmonton[107] were deployed to aid in disaster response efforts in British Columbia.

Premier John Horgan announced that a provincial state of emergency would be put in place and that travel restrictions would come into effect in order to protect the already-crippled supply chain.

[78] In response to the widespread damage and loss caused by the floods and mudslides, on November 17 GoFundMe set up a centralized hub for fundraisers for B.C.

[124] On November 19, a coalition of over 30 private and mostly local companies in Metro Vancouver led by Hootsuite partnered with the British Columbia and Yukon Red Cross to support disaster relief efforts.

[125][126] At the same time, some publicly traded corporations donated to various charitable organizations directly involved with the disaster relief efforts.

[127][128] In Washington, Governor Jay Inslee asked for the impacted counties to conduct damage assessment as part of his bid for disaster relief assistance from the US federal government.