Dike Management

As defined in the Dike Maintenance Act, a dike is an embankment, wall, fill piling, pump, gate, floodbox, pipe, sluice, culvert, canal, ditch, drain, or any other thing that is constructed, assembled, or installed to prevent the flooding of land. In British Columbia, dikes are works that address major flood hazards.

There are more than 200 regulated dikes in B.C. with a total length of over 1100 kilometres, protecting 160,000 hectares of valuable land.

The Lower Mainland is dependent on the integrity of:

  • 600 kilometres of diking
  • 400 floodboxes
  • 100 pumpstations

History

Diking in British Columbia started as early as 1864.

In 1894, the greatest flood on record occurred affecting extensive areas in the southern half of the province. Fortunately, development was still sparse and relatively little damage was caused. Later, as floodplain development continued, dikes were increasingly relied upon to protect these areas.

British Columbia’s second most damaging flood occurred in 1948 when a few dikes failed, resulting in:

  • Several casualties
  • Destruction of about 2,000 homes
  • Evacuation of 16,000 residents
  • Approximately $210 million (present day value) in damages

A 2015 study released by the Fraser Basin Council determined that a reoccurrence of the 1894 flood today could cause approximately $23 billion dollars in damages to the Lower Mainland. This emphasizes the importance of having properly designed, constructed and maintained dikes.

Background

Construction of new dikes, or upgrading of existing orphan dikes, will only be approved if:

  1. The local government has passed Council or Board resolution to become the diking authority and become responsible for ownership, operation and maintenance of the dike
  2. The diking authority acquires and maintains full legal access to the structure(s) through land ownership (fee simple) or registration of statutory right-of-way(s)

The following document provides guidance on how to manage dikes within the province:

Further guidance on the primary aspects of implementing and managing dikes:

Dike Safety Program

Provincial responsibilities and general supervision relative to the construction and maintenance of dikes lies with the offices of the Inspector of Dikes and Deputy Inspectors of Dikes.

Their responsibilities include:

  • Administering the Dike Maintenance Act
  • Setting dike design and maintenance standards and other criteria
  • Promoting dike management best practices
  • Monitoring and auditing management of works by local diking authorities
  • Approving changes to dikes and new dikes
  • Providing technical expertise for high risk diking issues

Dike Assessment

The B.C. Government and partners undertook an assessment of 74 dikes in the Lower Mainland. This assessment evaluated the level of protection provided by the dikes and identified major deficiencies.