When the wind blows

By District Staff on Tuesday, Nov 6, 2018

The month of November 2018 roared in like a lion, with back-to-back storm systems packing a considerable punch of rain and wind.

On the North Shore mountains, heavy rain reached a peak of 20 mm or three-quarters of an inch per hour in the wee hours of the morning of November 2, and strong winds and another heavy rainstorm followed closely behind.

This type of intense weather saturates and loosens soil, topples trees, and landslides can occur up in the alpine areas sending rocks, mud and woody debris down the mountainsides.

Prepping for storms even before they hit

When we're notified of impending severe weather by Environment Canada our response crews kick into high gear even before the weather arrives on our doorstep.

Teams from multiple departments head out to check on our culverts and ensure sandbags are ready for use should they be needed.

Critical infrastructure that handles storm water drainage was inspected and cleaned out by District crews prior to the first storm’s arrival on November 2, and again before the storm of November 4 hit.

Infrastructure that mitigates significant storm impacts

The debris basins, culverts and other system elements, some of which were improved or added after the Kilmer Creek flood of 2014, performed as they were designed to, and mitigated what could have been a much more significant impact had they not been in place.

Our larger culverts, which take the course of creeks under roadways and built-up areas, are about 8 feet wide by 5 feet tall. However when severe weather sends mud, rocks and trees down the mountainside it doesn’t take long for these large openings to get seriously jammed up.

That’s why we have debris basins, a system of big metal gates along the creek bed higher up the mountainside that stop the solid materials from heading down into the opening of a culvert, but let the water run through.

Thames Creek before the storm: Water flows normally through the metal gates along the creek bed and into the culvert beneath the road 

 

Thames Creek after the storm: Logs, woody debris, rocks, and gravel swept downstream by the rain are stopped before entering and blocking the culvert 

A 'risk-based' approach to managing hazards

At the District we use a risk-based approach to manage the natural hazards, focusing on both the likelihood and consequences of natural events such as landslides, debris flows, fires, severe storms, flooding, and earthquakes.

In 2011, we received the United Nations Sasakawa Award for Disaster Risk Reduction, and we are also recognized as a "Role Model City" for the United Nations Resilient Cities campaign.

Next time you hear the rain hammering down on a dark and cold night, rest assured that our crews were ready for it, and are out there monitoring the system, ensuring that it performs as designed.

Learn more about how we're managing extreme weather 

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