Flood Protection

Within the City of Chilliwack, there are floodplain areas for both the Fraser River and Vedder River. Portions of Greendale and Yarrow lie within the floodplain for both rivers.

The flood risk associated with these two river systems is different, and therefore the City has separate Flood Response Plans to manage the risks.  This webpage contains general information regarding flood protection and emergency preparedness for residents.  For more specific information regarding the Fraser River or Vedder River, please visit these webpages:

Fraser River
Flood Protection
Vedder River
Flood Protection


Flood Hazard - What Does it Mean?

Flood hazard is often expressed in terms of the likelihood or probability of a given flood event occurring. For example, the 1894 flood on the Fraser River is the largest flood on record, and is estimated to be a "1 in 500 year" event. The provincial dike standard and floodplain mapping for the Fraser River is based on this event.

The expression "1 in 500" does not mean that this size of flood will only happen once every 500 years.  For example, we can't say that because it happened in 1894, it won't happen again until close to the year 2400.   Rather, it means that there is a 1 in 500 chance of it occurring in any given year (1/500 = 0.2% chance per year).

Similarly, the provincial dike standard and floodplain mapping for the Vedder River is based on the "1 in 200 year" event. This means that there is a 1/200 (0.5%) chance of it occurring in any given year.

This explains why we can hear about large flood events, for example "1 in 100 year" flood events, happening two years in a row; the "1 in 100 year" events have a 1/100 (1%) chance of happening in any given year.

General Flood Hazard Management:

Flood hazard management is accomplished through a variety of measures, including:

 River Forecast Centre:

The Provincial River Forecast Centre collects and interprets snow, meteorological and streamflow data to provide warnings and forecasts of stream and lake runoff conditions around the province. Visit http://www.env.gov.bc.ca/rfc/ for current reports.

The City of Chilliwack uses the information provided by the River Forecast Centre when carrying out flood response activities.

 Flood and Emergency Information for Residents:

Download and print an Emergency Preparedness basic kit checklist (Grab & Go Kit). There are a number of resources that you can access to be prepared in the event of a flood.

The following government websites provide information on flood and emergency preparedness: www.getprepared.gc.ca, PreparedBCwww.chilliwack.com/ep and www.fraserhealth.ca

Additional Information for the Agricultural Sector:

The following websites provide information on flood and emergency preparedness for the agricultural sector:

Be Informed:

Due to variables such as weather, we cannot predict a flood with 100% certainty. Therefore, it is important that you make your plans on the assumption that flooding is a real possibility. The best thing for people to do is to review or establish personal and neighbourhood emergency plans and consider family members or friends who may need additional assistance. Please help those folks to be ready as well.

It is important to note that even if your home or business is located on higher ground, a serious flood event would result in a loss of key services like water, sewer, electricity and gas. In that case, a City-wide evacuation could occur. All residents should be prepared for at least a 72-hour period without services. We will provide as much information as possible to keep the public informed as waters start to rise.

 City of Chilliwack Floodplain/Elevation Maps:

Do you live in the floodplain?
Check this map to find out.
What elevation is your home at?
Check this map to find out.
Click to View Larger Floodplain Map
Download Chilliwack Floodplain Map
in PDF format with Road Names or without Road Names
Updated version as of May 3, 2007

The floodplain is accurately shown on this map as based on the 2007 update. When the next mapping update is completed, it is not expected to significantly change the extent of the floodplain.
Download Chilliwack Elevation Map
in PDF format (8.77 MB)
Description Date File Size 
Chilliwack Floodplain Map 2011-12-28 287KB 
Chilliwack Floodplain Map (with Road Names) 2011-12-28 430KB 
Emergency Grab and Go Bag 2011-12-28 44KB 
Floodplain Elevations 2012-06-28 9.21MB 
Floodplain Maps Frequently Asked Questions 2015-11-10 207KB 

Fraser River Flood Protection

Information and updates on the Fraser River Freshet and general flood protection information.

2023 Fraser River Freshet Information | Freshet FAQ’S (Frequently Asked Questions) | Flood History

Flood Evacuation Information

Preparing For An Evacuation: In flooding situations, residents in high risk areas should listen to the local media and follow the instructions of local emergency and transportation officials.

Flood Protection Infrastructure

Information regarding flood protection infrastructure

Young Road Dyke Project Update

In order to meet current provincial flood protection standards, this section of Young Road will be upgraded.