Water is a common thread throughout my previous OpenThink articles, from fining big polluters to preserving riparian areas. One topic that has not been discussed yet is the source of drinking water for one third of Canada’s population, and 80% of residents living outside of urban areas.
Water that comes from underground.
Groundwater is under-appreciated
Humans tend to care about things they can directly observe. For example, people are more likely to be concerned about climate change if they have experienced an extreme weather event like flooding.
Many people, especially those living in cities, don’t know where their tap water comes from. Groundwater makes up 97% of the world’s usable freshwater supply, but is seldom discussed in the public sphere. It’s invisible, but immensely important for life on Earth.
An aquifer is an underground ‘sponge’ of water, transported there from rain, snow, and ice runoff that seeps into the ground and settles between the holes within layers of rock. Water can stay in aquifers for up to thousands of years and discharge slowly over time, naturally filtered to be cold and clean.
Groundwater is drawn to the surface across many of the world’s largest watersheds. During the hot summer months, groundwater keeps rivers flowing when rain isn’t falling. In flatter areas, groundwater seeps sustain wetlands that contain carbon stores and unique plant and animal species.
A vulnerable water supply
Hydrogeology is the branch of Earth sciences concerned with groundwater, and this field of study has evolved drastically over time. Nowadays, simulation models are a common tool used to understand the structure and function of aquifers, and how they interact with people and the environment. When discussing solutions for managing groundwater supplies more sustainably, the relative inequity in water access between and within countries around the world cannot be overlooked.
Over one third of the world’s largest aquifers are “highly stressed,” meaning the rate of water extraction for human consumption is greater than the amount of water being recharged. Combinations of high human population density and a hot and dry climate generally results in a greater reliance on groundwater, and typically, a higher risk of aquifer overexploitation. The agricultural sector accounts for approximately 70% of the world’s groundwater withdrawals.
Despite being buried underneath layers of material, groundwater supplies are warming across the globe. Under a moderate emissions scenario, if atmospheric temperature rises 2.7°C by 2100, groundwater would be projected to warm by 2.1°C, on average. Even small temperature changes can induce microbial activity or kickstart chemical reactions (e.g., metal leaching) that may compromise the useability of a groundwater supply.
In Canada, water insecurity continues to be a major challenge in dozens of Indigenous communities. Most residents of the Six Nations of the Grand River, located 90 minutes from downtown Toronto, don’t have access to clean drinking water. Simultaneously, the Ontario government has permitted BlueTriton Brands Inc. (formerly Nestlé) to extract 3.6 million litres per day out of an aquifer located within Six Nations traditional territory to sell “spring water” out of plastic bottles, since 2007.
Protecting an invisible resource
Humans are pulling water out of the ground faster than it can be replenished, and the reliability of many future groundwater supplies is uncertain. Although advancing groundwater science has improved our knowledge of these systems, further research should focus on groundwater monitoring in under-studied regions. The 2022 United Nations Groundwater Report goes a step further to suggest that “oil and mining industries possess a great deal of data, information and knowledge on the composition of the deeper domains underground, including aquifers. It is highly desirable that they would share these with public sector professionals in charge of groundwater assessment and management.”
Countries with relatively plentiful groundwater stores (e.g., Canada) often give away their supplies to multi-national companies at a very low cost. Groundwater is a deeply valuable resource – if corporations want to take it for profit, they should be charged a hefty premium up-front and never at the expense of local citizens. Fees collected should go towards improving access to clean water in marginalized communities.
Demands for groundwater will continue to increase around the world, and it’s time that this invisible resource gets the attention that it deserves. At the international, national, sub-national, and local levels, concerted efforts are needed to protect groundwater for sustainable use into the future.
Photo by Hoang Trinh on Unsplash
