CSA W205:19 Erosion and sedimentation management for northern community infrastructure.
3 Definitions and abbreviations The following definitions and abbreviations shall apply in this Standard. Note: Annex E provides a glossary of translated terms: English to French, and French to English. Active layer — the upper layer of ground that thaws and freezes every year in areas underlain by permafrost. It does not always extend to the permafrost table in discontinuous permafrost. Active layer thickness depends on average air temperature, type of soil (coarse- or fine-grained), thickness of peat at ground surface, slope aspect, vegetation, compaction, etc. Note: See Annex A for more information on permafrost. Channel — the space above the bed and between the banks of a stream or ditch. Climate change — a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer.
5.2 Buffer zones and setback implementation
When implementing buffer zones and setbacks
a) avoidance has been shown to be the most effective means of reducing erosion and sedimentation risks. Buffer zones and setbacks are one of the most widely used land use planning tools for avoidance and shall be considered as a first option in coastal, lakeshore, riparian and slope- or
permafrost-related settings, except for access-related provisions;
b) buffer zones and setbacks around water shall be determined based on detailed hydraulic analysis, consideration of geomorphological evolution of the system, and anticipated climate change effects; c) human activity within the defined buffer area shall be limited in accordance with site-specific requirements;
d) the use of buffers shall include provision of a time frame for review to allow for change (adaptive management);
e) where possible, buffer zones shall incorporate elements of sustainable development as defined in existing guidelines such as the Northern Land Use Guidelines (DIAND 2003);
f) where possible, buffer zones shall be optimized to protect the local ecosystems; and
g) for built infrastructure that is already present within the buffer zone, the largest practical buffer/setback shall be set.
1) BC MoW (2004) (amended 2011 and 2017) provides the original guide and subsequent amendments to Flood
Hazard Area Land Use Management Guidelines.
2) DEFRA (2006) provides additional information on shoreline management plans.
5.3 Siting
The siting of new infrastructure shall be assessed in the context of strategic land use planning, with due
consideration for risk exposure and mitigation measures that might be required. The factors to be
considered shall include
a) building code and land use requirements;
b) local floodplain management and setback requirements;
CSA W205 pdf download.