Water well in a local green space

Groundwater

Groundwater is the water found underground in the cracks and spaces in soil, sand, and rock. The material that stores groundwater is known as an aquifer.

Despite being hidden below ground, 99% of all liquid fresh water on earth is groundwater. It is the most extracted natural resource in the world.

Almost 10 million Canadians depend on groundwater as a source of drinking water. Most Canadians also indirectly rely on groundwater because it is the primary source of water for livestock and crop irrigation in the country.

Although groundwater is a renewable resource, it is not limitless. Aquifers can be depleted when the rate of extraction exceeds the rate of replenishment. Contamination of aquifers is also a concern. Such challenges highlight the fact that groundwater needs to be managed sustainably.

Aquifers in Vancouver

Map showing location of main aquifers in Vancouver

Until now, the aquifers beneath Vancouver have been largely unmanaged because our potable water needs are being met by regional reservoirs which are fed by rainfall and snowmelt. However, groundwater has implications for the city's water security, buildings and infrastructure, and ecosystems.

As part of our One Water approach to integrated water management, we are working on projects that will help us better understand, protect, and sustainably manage local aquifer resources. These projects are within the City’s existing jurisdiction, and the Province of BC’s mandate with respect to groundwater remains unchanged.

Help protect local aquifers

Here is how you can protect local aquifers from contamination and depletion:

Never dispose of hazardous chemicals by pouring them onto the ground. Find out how to properly dispose of hazardous waste
Keep your vehicle in good repair to reduce leaks from oil, antifreeze, and other liquids that can find their way into the ground
Minimize the use of de-icing salts, pesticides, and fertilizers
Reduce paved areas in your yard to allow more rainwater to seep into the ground to replenish aquifers

Risks and opportunities

There are a number of groundwater-related risks that have already impacted Vancouver, and there are also many opportunities for the sustainable use of groundwater.

Risks

Flowing artesian conditions

In 2015, a contractor drilled a well for a home on Beechwood Street that pierced a pressurized part of the aquifer. An estimated 3 billion gallons of groundwater were released to the sewer system, and neighbouring homes were evacuated as a safety precaution.

Groundwater subsidence

Excessive pumping or draining of groundwater (especially in areas with soft soils) can cause sinking of the land, known as subsidence, which can lead to damage to property and infrastructure. This is an ongoing concern in some areas of Vancouver, as homes, sidewalks, and streets can be affected.

Ecosystems that depend on groundwater

Street trees, parks, and other ecosystems in the city often depend on shallow groundwater to survive, especially during prolonged periods of drought. Similarly, without adequate groundwater, urban streams (such as Still Creek shown below) are at risk of reduced flow, which can impact fish and other wildlife.

Flooding

Climate change is already causing more frequent and intense rainfall events. Sea level rise will lead to a rise in groundwater levels, which in turn will make it more difficult for rain to soak into the ground quickly. This can result in more frequent flooding events.
Opportunities
Vancouver uses drinking water from the North Shore reservoirs, which are under increased demand as a result of climate change and population growth. That’s why we are exploring alternative water sources for purposes that don’t require potable water.

Using groundwater sustainably for some non-potable uses could help conserve drinking water. Examples of potential future uses of groundwater include:
- Activities in homes and businesses such as flushing toilets
- City operations such as irrigation of parks, street cleaning, and watering flower beds and street trees
Groundwater could even be used as a source of drinking water during emergencies, such as following an earthquake.