Lower Mainland Dike and Emergency Maps
- Lower Mainland Dike Inventory Maps
- Emergency Planning Floodplain Maps (Lower Fraser River)
1. Lower Mainland Dike Inventory Maps
The Lower Mainland Dike Inventory maps show the flood protection infrastructure regulated under the Dike Maintenance Act. The series of map sheets covers the Lower Mainland Region (the lower Fraser River and tributaries, and the sea), the Squamish area (Squamish and Cheakamus Rivers), Whistler, and the Pemberton Valley (Lillooet River).
The maps contain information on:
- dike infrastructure, pump stations, floodboxes, riprap, relief wells
- known areas of hazard concerns, boil locations, low dikes, etc.
- major road & street network showing access points onto dikes
- other infrastructure relevant to safe operation of the dikes, such as major pipeline crossings, hydro lines, railway lines, etc.).
Compilation of the information came from various sources including TRIM, orthophotos, as-built drawings, O&M manuals, diking authorities, and historic records.
The October 2009 map revision includes the accepted Fraser River flood profile plus freeboard for the Lower Fraser Valley from Laidlaw near Hope to the mouth of the Fraser River. Background details on this profile and the study which it is based may be found on Water Stewardship's Dike information web page (see item 9, March 2008 revision)
Please note: the crest elevations of the dikes in the Lower Fraser River floodplain have not been evaluated against this new profile and may be lower than the elevations of this new profile plus freeboard.
As of June 1, 2011, a number of maps were revised with relatively minor changes. (The Fraser River profile remains unchanged.) The revised maps have been marked with an *. In addition, there is now a new map covering most of North Vancouver. An overall index map has also been provided.
The floodplain extent shown on the maps is based on old data and flooding may occur outside of the floodplain areas shown.
The maps are an important resource supporting a range of needs that include the Inspector of Dike’s regulatory responsibilities: flood emergency planning, preparedness, and response; broad-based floodplain management, planning and reviews; and other related activities.
The dikes and dike-related infrastructure and the floodplain inundation areas shown on the Lower Mainland Dike Inventory maps are compiled resource information to support flood emergency preparedness planning AND response. The map sheets are to help local authorities with broad-based floodplain management plans and related activities.
The data was compiled from various sources. It is not warranted as to its accuracy or sufficiency by the Ministry of Environment and is not intended for legal purposes. The maps are provided for the purposes of information and convenience only.
They are NOT intended to replace detailed floodplain maps designated under the 1987 Canada/B.C. Floodplain Mapping Agreement. FLOODING MAY OCCUR OUTSIDE THE FLOODPLAIN AREAS SHOWN.
Lower Mainland Dike Inventory Maps
2. Emergency Planning Floodplain Maps for the Lower Fraser River
Emergency planning maps have been updated June 1, 2011 to reflect relatively minor changes to the diking system since 2009. The Fraser River flood profile plus freeboard remains unchanged.