As the snowfall along the Fraser River and Alouette River systems melts each spring, the snowpack, river conditions, and intense rainfall create a risk of flooding in Maple Ridge.
Alouette Valley Flood Response
While the North and South Alouette rivers have independent rainfall catchment areas, their downstream floodplains can interconnect during rainfall events. Both rivers are unconfined (without dykes) and flow rates are driven by the intensity of local rainfall. BC Hydro can decrease some of the flooding for the South Alouette River, depending on rainfall intensity, available storage volume, and the dam spillway capacity.
The City’s study of the North and South Alouette River watercourses has resulted in the North Alouette and South Floodplain Analysis in 2016 and the completion of Integrated Stormwater Management Plans in 2021. To more accurately forecast flood events, the City has since commissioned additional work to better correlate precipitation within the two rainfall catchments with BC Hydro dam operations. This work will culminate in a Flood Response Plan for the Alouette Valley.
Map of flood risk associated with the North & South Alouette Rivers:
Potential Flood Extents — North and South Alouette Rivers
Fraser River Flood Plan
The City of Maple Ridge has developed a Fraser River Flood Plan that is connected to the data from the BC River Forecast Centre. The City's response plan includes:
- Daily monitoring of weather forecasts and river levels
- Patrolling, inspecting and maintaining dikes and pump stations
- Preparing and disseminating flooding and flood preparedness information to the public
- Liaising with other government and utility organizations
- Developing contingency plans
- Updating the City's evacuation plan as necessary
Flood Monitoring
The City of Maple Ridge monitors rainfall amounts around the city and water levels in the Fraser River, North and South Alouette River, and Kanaka Creek. View information gathered by our three rainfall gauges and eight hydrometric (stream) gauges: View live rainfall measurements and water levels.
For more water level data:
Flood Warnings & Current Conditions
The BC River Forecast Centre is responsible for issuing flood watches and warnings for rivers around the province.
Common Flood Terms
Flood Warning
River levels have exceeded bankfull or will exceed bankfull imminently, and areas adjacent to affected rivers will experience flooding.
Flood Watch
River levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur.
High Streamflow Advisory
River levels are rising or expected to rise rapidly, but, no major flooding is expected. Minor flooding in low-lying areas is possible.
Weather and Utility Information
Do You Live in the Floodplain?
A floodplain is land adjacent to a watercourse that is susceptible to flooding. A floodplain map outlines the area that can be expected to flood, on average, once every 200 years. This is called the 200-year flood. A 200-year flood can occur at any time in any given year; the indicated flood level may be exceeded; and portions of the floodplain can flood more frequently than others.
Check our North and South Alouette River Floodplain Map or our Fraser River Floodplain Map to find out whether you live in the floodplain.
Prepare for a Flood
Maple Ridge is no stranger to rain, and sudden and heavy rainfalls can pose a serious risk. Localized flooding can lead to dangerously fast-rising water levels and impassible roads, and when combined with warm weather, melting snowpacks can create landslides.
How to Prepare
- Review Emergency Planning for information on disaster preparedness.
- Build or restock your Emergency Preparedness Kit.
- Check local forecasts and consider the conditions, especially if you are planning to enjoy the trails and river systems.
- Prepare your family plan and your property.
- Check with an insurance agent on flood insurance for your home and business, and take a personal inventory of your belongings.
- Ensure roof gutters are clear and storm drains are free of debris such as leaves.
- If you live near a waterway and notice trees beginning to lean and bend near your home, or cracks developing in the hillside, consult an engineer or contact local authorities.
- When a flood is expected, park vehicles away from streams and waterways, move electrical appliances to upper floors and make sure to anchor fuel supplies. Listen to local officials if you are asked to evacuate.
Review our Flood Safety Checklist.
Sandbagging
- It takes two people about one hour to fill and place 100 sandbags, creating a one-foot-by-20-foot wall. Make sure you have enough sand, burlap, plastic bags, shovels and time to prepare properly.
Learn How-To Sandbag.
During Flooding
- If your home is near water, note if the water level begins to rise quickly. A change in water colour or rapid change in water level (especially a drop) could indicate a problem upstream. Call your local fire, police or public works department immediately if you suspect something out of the ordinary.
- Avoid getting close to fast-moving water as banks may erode without warning.
- Keep a close eye on children and pets as they may not understand the dangers.
- Plan alternate routes before driving if low-lying roads become flooded. Slow down and provide yourself with extra time.
- Never drive through moving water, even if you are familiar with the road. A vehicle can be swept away in as little as 12 inches of water.
- Monitor the local media and have flashlights on hand in case the power goes out.
After Flooding
- Check your property for damage and clear away debris from rain gutters and storm drains.
- Even though the rain has stopped, waterways may still pose a risk. Be cautious until you are certain of the conditions.
- If you have suffered from flood damage, contact your insurance company.
