Flood and the Fraser

With rivers come risk — including the risk of flood. For more than 25 years, the Fraser Basin Council has worked to support provincial and local authorities in carrying out their respective responsibilities for flood mitigation.

Most years there is flood, or risk of flood, somewhere in British Columbia.

The risk of catastrophic loss from Fraser River or coastal flooding is significant, and it is greatest in the Lower Mainland because of a large population (over 300,000 people) and extensive residential, commercial, industrial, utilities and transportation infrastructure and agricultural operations in floodplain areas. The Fraser Valley and other parts of the Fraser Basin have experienced two major Fraser River floods of record, the largest in 1894 and the second largest in 1948.

A Look Back

Red Cross rescue during the 1948 Fraser Valley flood. Photo: Vancouver Public Library.

The largest Fraser River flood on record was in May, 1894 when rapid snowmelt caused river levels to rise dramatically, triggering flooding from Harrison to Richmond. The flood was massive; however, property damage was limited because settlement was sparse. The next largest Fraser flood of record was in 1948. Because of increased development and population growth in the floodplain, the impacts were much greater than in 1894. According to the Province of BC, this included:

• evacuation of 16,000 people
• damage or complete destruction of about 2,000 homes
• $210 million in damages (2010 dollars).

For more on the history of the 1894 and 1948 Fraser River floods, visit the FloodWise website.

Preventive planning and flood protection are critical in the region since a major region-wide flood would have severe social, economic and environmental consequences. These include risk of injury and loss of human life, deaths of many animals kept as livestock in floodplain areas, damages and loss of property, temporary loss of infrastructure and community services, disruption of business and trade,  degradation of water quality and harmful impacts on fish and wildlife habitat.

Phase 1 of the LMFMS estimated economic losses of $20-30 billion from a major Fraser River or coastal flood in the region between now and 2100. Learn more about the Phase 1 results.

Integrated Flood Management

Nature controls the timing and severity of flood events, but communities can reduce the extent of damage through land use planning, floodplain bylaws, flood protection works, floodproofing measures and emergency flood plans. Combined, these activities provide an integrated approach to flood hazard management.

Today in the Fraser Basin, there are about 600 km of dikes, 400 floodboxes and 100 pump stations to protect communities and infrastructure from flooding. Although dikes and drainage are critical infrastructure, land use planning is also pivotal to minimizing risk of catastrophic loss, and this may include community decisions to limit development and infrastructure in floodplain areas.

Flood Maps for Lower Fraser and BC

For regional planning purposes, the Lower Mainland Flood Management Strategy initiative developed 2D regional flood maps. These are available on this site and on the FloodWise site.

The regional maps were to intend inform region-wide planning and are not at a sufficiently detailed scale to support any consideration of individual properties. If you have questions about a location in or near the floodplain, contact your local municipal hall for local floodplain maps.