The Lower Mainland is a name commonly applied to the region surrounding Vancouver, British Columbia, Canada. As of 2007, 2,524,113 people live in the region; sixteen of the province's thirty most populous municipalities are located there.

While the term Lower Mainland has been recorded from the earliest period of non-native settlement in British Columbia, it has never been officially defined in legal terms. The British Columbia Geographical Names Information System (BCGNIS) comments that most residents of Vancouver might consider it to be only areas west of Mission and Abbotsford, while residents in the rest of the province consider it to be the whole region south of Whistler and west of Hope. However, the term has historically been in popular usage for over a century to describe a region that extends from Horseshoe Bay south to the Canada – United States border and east to Hope at the eastern end of the Fraser Valley.

Population

In 2007 there were 2,524,113 people living in the communities of the Lower Mainland, of whom:

• 274,388 lived in the Fraser Valley Regional District
• 2,249,725 lived in the Greater Vancouver Regional District (since renamed to Metro Vancouver)

The population in the Lower Mainland was up 10.4% from the 2001 Census figures. This is among the highest trends in the continent.

Communities

Fraser Valley Regional District

• Abbotsford
• Chilliwack
• Kent/Agassiz
• Mission
• Hope

Metro Vancouver

• Anmore
• Belcarra
• Bowen Island
• Burnaby
• Coquitlam
• Delta
• Langley City
• Langley District

Metro Vancouver

• Lions Bay
• Maple Ridge
• New Westminster
• North Vancouver City
• North Vancouver District
• Pitt Meadows
• Port Coquitlam
• Port Moody
• Richmond
• Surrey
• Vancouver
• West Vancouver
• White Rock

Regional Districts and First Nations territories

Today, the Lower Mainland includes two Regional Districts: Metro Vancouver and the Fraser Valley Regional District (FVRD). Both regional districts, however, include areas outside the traditional limits of the Lower Mainland.

Metro Vancouver is made up of 21 municipalities. Metro Vancouver is bordered on the west by the Strait of Georgia, to the north by the Squamish-Lillooet Regional District, on the east by the Fraser Valley Regional District, and to the south by Whatcom County, Washington, in the United States. The traditional territories of the Musqueam and Tsleil'waututh lie completely within the metro area; the southern portion of Skwxwu7mesh (Squamish) traditional territory is also in the metro area — its claims overlap those of the Tsleil-waututh, Musqueam, and Kwekwitlem. Other peoples whose territories lie within the regional district are the Katzie, Kwantlen, Tsawwassen and Semiahmoo, some of whose territories overlap with those of the Musqueam. Many other peoples of the Georgia Strait region also frequented the lower Fraser, including those from Vancouver Island and what is now Whatcom County, Washington.

The Fraser Valley Regional District lies east of Metro Vancouver, comprises the cities of Abbotsford and Chilliwack, the district municipalities of Mission, Kent, and Hope, and the village of Harrison Hot Springs. It also includes a series of electoral areas throughout the Fraser Valley and along the west side of the Fraser Canyon. The traditional territory of various Sto:lo bands is partly within this regional district, as is the entirety of the Sts'Ailes (Chehalis) (who do not consider themselves Sto:lo though historically speaking the same language). Sto:lo traditional territory more or less exactly coincides with the traditional conception of the Lower Mainland, except for their inclusion of Port Douglas, at the head of Harrison Lake which is in In-SHUCK-ch territory.

Lower Mainland Ecoregion

"Lower Mainland" is also the name of an ecoregion — a biogeoclimatic region — that comprises the eastern part of the Georgia Depression and extends from Powell River on the Sunshine Coast to Hope at the eastern end of the Fraser Valley. The Lower Mainland Ecoregion is a part of the Pacific Maritime Ecozone The provincial Ministry of Environment bases its Lower Mainland Region on this ecoregion, rather than on the traditional Lower Mainland alone.

Natural threats

Flooding

The Lower Mainland is considered to have a high vulnerability to flood risk. There have been two major floods, the largest in 1894 and the second largest in 1948. According to the Fraser Basin Council, scientists predict a one-in-three chance of a similar-sized flood occurring in the next 50 years.

In the spring of 2007, the Lower Mainland was on high alert for flooding. Higher than normal snow packs in the British Columbia Interior prompted the municipal governments to start emergency measures in the region. Dikes along the Fraser River are regulated to handle about 8.5 metres at the Mission Gauge (the height above sea level of the dykes at Mission). Warmer than normal weather in the interior caused large amounts of snow to melt prematurely, resulting in higher than normal water levels, which, nevertheless, remained well below flood levels.

Flooding can cover much of the Lower Mainland. Cloverdale, Barnston Island, Low-lying areas of Maple Ridge, west of Hope, White Rock, Richmond, parts of Vancouver and parts of Surrey are potentially at risk. In 2007, the Lower Mainland was largely spared, although northern regions of the province, along the Skeena and Nechako Rivers experienced floods. Climate scientists predict that increasing temperatures will mean wetter winters and more snow at the high elevations. This will increase the likelihood of snowmelt floods.

The provincial government maintains an Integrated Flood Hazard Management program and an extensive flood protection infrastructure in the Lower Mainland. The infrastructure consists of dikes, pump stations, floodboxes, riprap and relief wells.

Earthquakes

While earthquakes are common in British Columbia and adjacent coastal waters, most are minor in energy release or are sufficiently remote to have little effect on populated areas. Nevertheless, earthquakes with a magnitude of up to 7.3 have occurred within 150 kilometres of the lower mainland.

Based on geological evidence, however, the possibility of earthquakes with a more massive release of energy is a generally accepted possibility. Such massive earthquakes appear to have occurred at approximately 600-year intervals. Thus there is a probability that there will be a major earthquake within the next 200 years within the region.

In April 2008, the United States Geological Survey released information concerning a newly-found fault line south of downtown Abbotsford, called the Boulder Creek fault. Scientists now believe this fault line is active and capable of producing earthquakes in the 6.8 magnitude range.

References