Receding waters gave way to a mammoth cleanup of affected areas, aided by a spontaneous volunteer campaign in which many homeowners were assisted by complete strangers.

This blocked circulation and easterly winds pumped humidity on the rising slopes of the Rocky Mountains foothills, causing heavy rain into the province with rainfall amounts of over 200 millimetres (7.9 in) to fall in less than two days[when?]

The rain falling on already saturated ground, coupled with the steep watershed and heavy snow loads remaining in the front ranges of the Rocky Mountains, resulted in a rapid increase in the size and flow of several rivers.

[11] According to data tracked by Alberta's Ministry of Environment and Sustainable Resource Development,[12][13][notes 1] "in the space of a day or two, the flows of the three rivers rocketed up five to 10 times their normal rates."[when?

[16] As communities began to flood and people became displaced, area residents mobilized to offer support and assistance to evacuees and emergency response personnel.

Some volunteers and several police officers worked up to 20 hours to help evacuation efforts despite knowing their own homes had been damaged or completely washed away.

[17] While coverage of the flooding spread throughout social media sites, many people and businesses also took to Facebook and Twitter to open their homes up to neighbours and strangers who did not have other places to stay or offer whatever support they could.

[19][25][26][notes 8] The city's largest indoor arena, the Scotiabank Saddledome, was among the facilities damaged as flood waters were reported to have filled up to the first ten rows of the lower seating bowl.

[27] The Calgary Stampede grounds adjacent to the arena were also severely flooded, less than two weeks before the scheduled opening of the annual exhibition and rodeo, however officials vowed the event would go on.

[28] While emergency officials began to announce the partial lifting of some evacuation orders on June 22,[29] Mayor Naheed Nenshi stated that it would be several days before power could be restored to the downtown core.

[30] City workers, assisted by Canadian Forces personnel from The Calgary Highlanders, reinforced a particularly large erosion of river bank near 8th Avenue S.E., which endangered several houses in the neighbourhood of Inglewood.

All 13,000 residents of High River were ordered to evacuate on June 20, and the community was largely abandoned within three days as the town suffered what local officials called "unprecedented" damage.

[40] Among internationally recognized sites flooded in High River was the "Maggie's Diner" standing set for the Canadian Broadcasting Corporation (CBC) series Heartland.

The Province of Alberta decided to purchase 94 homes located in designated floodways (including the 32 in Beechwood), demolish most of them and return the area to its natural state as a floodplain.

[46][47] The mountain towns of Banff and Canmore, west of Calgary, were cut off from neighbouring communities after flooding and mudslides forced the closure of the Trans-Canada Highway.[when?

[64] Alberta's Minister of Municipal Affairs, Doug Griffiths, announced on June 21, 2013 that a task force that represents numerous government agencies and which earned praise for its coordination of recovery efforts following the 2011 Slave Lake wildfire would be reconvened.

[65] John McGowan, CEO of the Alberta Urban Municipalities Association (AUMA) described how AMSC is applying what they learned from the $700-million clean-up process following the Slave Lake fire in 2011 in their response to the flood.

[66] Upon touring the affected areas, Alberta Premier Alison Redford who represents the Calgary-Elbow riding, promised provincial assistance in recovery efforts.

[7] The Alberta Treasury board met early on June 24 to approve a preliminary $1 billion emergency fund for the disaster recovery program, covering immediate clean-up and repair costs.

[68][69] Prince William and his wife sent on June 24, via the Canadian Secretary to the Queen, a message of support, expressing their "best wishes to the Lieutenant Governor and Premier of Alberta and to the brave emergency services and all those volunteering to help their neighbours during this ongoing period of intense efforts.

"[70] His father, then Prince Charles also, following the destruction of Lac-Mégantic, Quebec, on July 8, issued a statement mentioning both that disaster and the Alberta floods, saying "this has been a most testing time for Canadians" and praising the "extraordinary efforts which have led to the Calgary Stampede being opened on time" as demonstration that "it is only too clear how courageous and resourceful Canadians are, and we have nothing but the greatest admiration for such determination and resilience in the face of terrible adversity.

"[71] Prime Minister Stephen Harper, who also represents the Calgary Southwest riding, toured the flooded area and promised federal assistance in recovery efforts.

[7][67] Harper, Redford and Calgary Mayor Naheed Nenshi took a helicopter tour of flood-damaged areas on the afternoon of June 21, and discussed the trilateral co-operation to the flood response.