Componente institucional

New industrial/commercial/institutional buildings should not be located within fan or floodplain areas that are not protected by standard/adequate structural mitigation works unless:

the local government has adopted an appropriate by-law or land use regulation that provides for building construction with knowledge of the flood hazard; or

the QP concludes that the site may be suitable for the intended use.

A QP may conclude that the site may be suitable for the intended use if at least one of the following conditions applies:

the building site is on an inactive fan;

a standard/adequate dike or equivalent other structural mitigation works is constructed as part of the development;

the building site is not in a high hazard area of the fan or floodplain (as noted above and where safe access and egress is not possible); and/or

a risk assessment is undertaken whereby the local government establishes a tolerable

level of risk, and the QP assessment confirms that the risk would be within this level. Standards for new industrial/commercial/institutional buildings should consider the standards for single houses. Variances of the standards is discouraged.

Some specific considerations pertaining to industrial buildings are as follows: water-oriented industrial buildings may be located outside standard dikes;

relaxation of the FCL may be considered, especially for heavy industrial buildings behind

standard dikes; and

for proposed major industrial developments, a risk assessment may be considered as a basis to develop site-specific mitigative measures.

Some specific considerations pertaining to commercial buildings are as follows: commercial buildings should generally not be located outside standard dikes; and

the specification of floodproofing measures shall consider the potential for different building use in the future as per the applicable land zoning.

Some specific considerations pertaining to institutional buildings (schools, universities,

hospitals, fire halls, police stations, emergency response headquarters, churches, community centres, etc.) are as follows:

institutional buildings should not be located outside standard dikes;

institutional buildings should be considered as potential places of local refuge during flood emergencies, so the FCL should not be relaxed; and

institutional buildings should have appropriate access/egress in view of their potential use during flood emergencies.

In view of the wide variance of the sizes and types of industrial, commercial, and institutional buildings, it is recognized that hazard mitigation may be site-specific.

G3 S

An Approving Officer may require a flood assessment for a new subdivision in a potential flood

hazard area.

Regardless of any bylaw or development approval requirements, it would be prudent for the

QP to ask the local authority to make the report (in whole or in part) available to future landowners through registration of an appropriate restrictive covenant.

Where there are local government by-law provisions and/or restrictive covenants that

appropriately govern the project, those provisions should be followed. Any proposed variances to those provisions should be subject to consultation with the local and/or provincial

government in consideration of the measures outlined below.

This section outlines some principles and measures that constitute appropriate professional practice when making submissions for subdivision applications.

At an early stage in the subdivision process, the QP should consult with the Approving

Authority regarding the role of dikes and other structural mitigation works, as well as the need for a risk assessment. In general, unless the applicable regulations provide appropriate

direction in view of the scale of development and flood hazard type, a risk assessment is likely to be more appropriate for medium or larger proposed subdivisions (over 10 single family units as defined in Appendix E) in areas protected by standard/adequate works, and for any

proposed subdivisions in areas not protected by standard/adequate works. A risk assessment

can help determine the suitability of a site for the intended use, and to refine proposed flood risk reduction measures to be incorporated as part of the proposed development.

Some common items that apply to each subdivision are as follows:

the building area of the development shall be set back an appropriate distance from the creek or river in view of the potential for long-term erosion (without the need for erosion protection works);

buildings shall be elevated to an appropriate FCL;

in addition to hydraulic considerations, the FCL shall include the effects of linear fills such as roads and railways;

the FCL applies to the underside of a wooden floor system, or the top of a concrete floor system used for habitation or the storage of goods susceptible to damage by floodwaters;

Professional Practice Guidelines - Legislated Flood

APEGBC  June 2012 Assessments in a Changing Climate in BC 119

no area below the FCL shall be used for habitation, business, the storage of goods damageable by floodwater, or the installation of fixed equipment;

the method of achieving the FCL (fill, structural, or any combination) shall be appropriately specified;

areas used solely for vehicular parking may be located below the FCL;

the design of the building foundation should consider hydraulic loading and scour); where the development is subject to a dike setback, any expansion shall not be within 7.5

m of the dike toe or dike right-of-way unless accepted by the local diking authority and the

Deputy Inspector of Dikes; and

the need for a future dike right-of-way should be considered (if appropriate through consultation with the local diking authority), and recommendation for a dike right-of-way may be made.

Where a site has suitable development areas outside the hazard area, or an area subject to a lesser hazard, a preferable approach is to require buildings to be located in such non-hazard or lesser hazard area. Alternatively the land development density can be lowered within the hazard area, while compensating with an increase in development density outside the hazard area.

In general, new subdivisions should not be constructed on unprotected fans or unprotected floodplain areas. Unless otherwise regulated by the local authority, a preferable approach for such areas is as follows:

undertake a comprehensive FHA;

consider a formal FRA in consultation with the local authority; implement effective land use regulations through the local authority;

protect a subdivision in a floodplain with a standard dike having a design return period of at least 200 years;

protect a subdivision on a fan with standard structural mitigation works;

designate a local diking authority (typically local government) to be responsible for the works in perpetuity;

ensure that all protective works are conservatively situated, located on a right-of-way, and designed in view of long-term fluvial geomorphological processes, land use, and climate change;

prepare an operation and maintenance manual to facilitate the functions of the local diking authority in a manner that is consistent with provincial and federal environmental

regulations; and

develop appropriate secondary floodproofing measures for the development area.

The standard dike level of protection is strongly preferred for proposed subdivisions, however

as noted in section G-1.2, there may be situations where this level of protection cannot practically be provided, but where the works are considered adequate for the purpose of the proposed development.