Floodplain ​& Dikes

home-alertCOVID-19: Things are evolving daily and the page below may not be current, get the latest updates on City facilities, services and programs at coquitlam.ca/covid19.

Note also that many services are available online to continue to serve the community at this time.

Floodplain & Dikes

The City of Coquitlam currently fronts four major rivers: Brunette, Coquitlam, Pitt and Fraser River. In 2014 the City developed a floodplain map outlining the areas that would be affected in the event of a flood.

Flood Events Analyses: 2014, 2100, 2200

Kerr Wood Leidal (KWL) analyzed the flood events, accounting for climate change, and generated Year 2200 Floodplain Maps​ together with a table, which provides stationing (location) and flood elevations for the 2014, 2100 and 2200 flood events, including freeboard.

What to Know For Developing in Floodplains

The Fraser River Flood Level is established based on the historic 1894 flood levels, which saw flows of nearly 19,000 m3/s in the District of Mission. 

The Pitt River is connected to the Fraser River, and its flood elevations near the confluence of the two rivers are established from the Fraser River Flood Levels as follows:

  • 2014: 4.92m Geodetic
  • 2100: 5.84m Geodetic
  • 2200: 7.15m Geodetic

The Coquitlam River Flood Levels were designed based on the design 200-year flood, which is a flood that can occur on average once every 200 years.

Coquitlam/Fraser/Pitt Rivers Floodplain Mapping Report

Dikes

Coquitlam has several dikes surrounding low-lying properties that protect land from inundation if the river level rises. The properties protected by the dikes require pumps stations, which take the water from the lower lands and pump it into the river when levels are high. 

Freeboard

As per the City’s bylaw, freeboard is the vertical distance added to the design Flood Level, to establish the Flood Construction Level (FCL). Provincially freeboard is the either 0.3m above the instantaneous 200-year peak water level or 0.6m above the daily 200-year peak water level.

Climate Change

Climate change can affect both peak sea levels and peak flows in watercourses. The current estimation for Sea Level Rise (SLR) is 1m by 2100 and 2m by 2200. The City’s floodplain maps consider the projected SLR.

Engineering ​& Public Works Customer Service
604-927-3500
epw@coquitlam.ca