By Alfonso Rivera
The knowns and unknowns of ground water in Canada
By Alfonso Rivera
Whereas oil, gas, uranium, and other metal and mineral reservoirs (including diamonds!) are understood in this country, ground water reservoirs are still not fully understood.
Ten to 15 years ago, we used to underline the knowledge gaps as the main issue concerning ground water and aquifers in Canada that we needed to fill in to develop good management practices. Where are we now as we approach the end of the second decade of this new millennium? The desire to know still moves us.
We read of the great importance of ground water in California, India, Mexico, Israel, Spain and many other countries. We learn that in those countries, ground water is simply a primordial commodity for subsistence, an elemental resource, one without which people in those countries could not survive nor develop their agriculture, industry and urbanization. The common threads of those countries: they are located in the arid or
semi-arid regions of the world, where precipitation is small (or scarce), evapotranspiration is high – sometimes higher than precipitation – and runoff (surface water) is virtually non-existent.
And what about us here in Canada? Is ground water as important in Canada as it is in those countries? There is of course no single, straight answer to those questions. Our country is big, our climate is variable and may be extreme, our population is small, and the issues are not comparable. Yet ground water is indeed important in Canada too.
If you live in a small to medium-size city, chances are one in three that you rely on ground water on a daily basis. That is 33 per cent of Canadians, or about 11.5 million people, using ground water for drinking, cooking and all other day-to-day usages. On the other hand, if you live in a rural area, the chances of using ground water are more than 70 per cent because wells are often more reliable and less expensive than water systems pumping from nearby lakes and rivers.
When it comes to determining the volume of ground water used by Canadians, hydrologists are mostly in the dark. In other places, such as the southwestern U.S., unsustainable ground water use is resulting in land subsidence, saltwater intrusion and contamination. Fortunately, we don’t have those problems here in Canada. If we could collect more data – so we’re able to measure how much we have and where, what we use and how vulnerable it is – we’d be better off than anywhere else.
With about one-half of one per cent of the world’s population, Canada has a disproportionate global share of water. But ground water is just one part of the country’s vast water resources, which include millions of lakes and hundreds of rivers. In fact, the surface area and number of lakes in North America far exceed those of any other continent. Canada alone has at least three million lakes and, in some regions, there are as many as 30 lakes for every 100 square kilometres. But poor distribution, wasteful use and new stresses are three factors that contradict this apparent water wealth.
The importance of ground water, however, is not restricted to the quantities in which it is used, or to the steady growth in its use, but also to the particular people it serves and the areas where it is used. The close relationship between ground water and surface water – for example, the fact that a decline in ground water will reduce surface flows – is not universally understood or appreciated.
Another important case in Canada is related to ground water-dependent ecosystems (GDE). A GDE is a community of micro-organisms, animals and plants, and associated substrates, whose functioning relies on the presence of water under the ground and/or its emergence to the surface (ground water and aquifers). Some GDEs are supported entirely by ground water while others also receive water from different sources, but the ground water contribution is critical as regards water chemistry to nourish certain species, and provide stable water temperature and absence of sediment load. There exist numerous ecosystems, for example, wetlands, across Canada, which rely on ground water, but their interactions with ground water are not fully understood.
Moreover, the importance of ground water protection is not adequately taken into account in water management. There is a need for greater public awareness of the value of ground water and an understanding of how it is regulated. For instance, provincial and territorial permitting and licensing requirements for ground water should address not only domestic and industrial needs but also the environmental consequences of withdrawals (quantities) of ground water.
Some of the fundamental questions and issues that frame the need for more ground water knowledge include:
- Availability of ground water (how much) and location of aquifers (where).
- How much water are we really using (towards sustainability and protection of ground water).
- Water-energy nexus (oil and gas, CBM, shale gas).
- Interactions between ground water, surface water, aquatic ecosystems and land use.
- Transboundary aquifers and ground water (interprovincial and international).
- Growing agriculture, industry, and domestic ground water use.
- Ground water monitoring and climate variability and change.
- Use of modern satellite technology as applied to ground water resources.
- Availability of unified, national-scale data and information on ground water and aquifers.
- Major aquifers in Canada and the state of ground water development.
- Are Canada’s ground water dynamics controlled by climatic conditions and ecosystems, or stressed by human-dominated irrigation, domestic or industry use (something known as the anthropogenic biome)?
- How sustainable is the current use of the ground water resources of Canada?
We still cannot answer all these questions or resolve these issues. We have identified the available information about this resource – a starting point that is necessary for management decisions. But the data and information are still not sufficient. Yet water management that does not include ground water will be incomplete. The most up-to-date overview and synthesis on the status of ground water resources in Canada was recently compiled in the 2014 book Canada’s Groundwater Resources. The current knowledge of ground water in Canada is mostly based on the regional aquifer assessments the Geological Survey of Canada (GSC) of Natural Resources Canada has been carrying out in co-operation with the provinces over the last 15 years. The book summarizes the state of scientific knowledge of aquifers and ground water in Canada as of 2014 and identifies the knowledge gaps, issues and trends we still need to address.
The ultimate task of a full ground water inventory for the whole of Canada is a significant one: some persistent and emerging issues not covered by individual aquifer assessments still need to be addressed at the national scale. For example, individual aquifer assessments carried out by the GSC for the 30 key Canadian aquifers cover less than 600,000 square kilometres (approximately six per cent of the Canada landmass), thus they cannot cover persistent and emerging issues at the national scale.
Concerns in changes over climate, alternative energy production, territorial responsibility and First Nations are often not considered in programs and projects on aquifer mapping. New and looming issues should be tackled using new and emerging methods (for example, remote sensing, ground water flow systems, water budgets), to support improved knowledge of specific issues. To tackle these, a regional- and continental-scale integration of aquifers and ground water knowledge has become obvious and urgently needed.
However, not everything is as dark as it seems. Very good progress has been made in many different ground water-related domains by many different groups in Canada. New initiatives are being launched by provinces and federal agencies.
For instance, the Canadian Council of Ministers of the Environment (CCME, 10 provinces, three territories and two federal departments) has recognized ground water as “the main source of water for almost 10 million Canadians.” It is critical to human health, to important aspects of the economy and to the viability of many ecosystems, the CCME says. The CCME developed and tested an approach for assessing the sustainability of ground water resources at a local, regional or Canada-wide scale. The resulting Groundwater Sustainability Assessment Approach (GSAA) is a high-level framework that can be interpreted for application across various scales, locations and circumstances. To support the use of the GSAA, CCME has recently developed a guidance document meant to assist users to successfully apply the GSAA.
Other great initiatives include the Quebec PACES program (Programme d’Acquisition de Connaissances sur les Eaux Souterraines), which addresses ground water sustainability and provides useful context for the implementation of the GSAA; and the Alberta Groundwater Mapping Program, which was identified in the 2009 Water for Life Action Plan as a key action to improve knowledge about Alberta’s ground water resources.
We also are encouraged by the recent adoption of new ground water licensing regulations by the province of British Columbia, the last of the provinces to adopt regulations for ground water use.
Finally, to speed up the mapping and to complement the assessment of aquifers and ground water resources in Canada, the GSC is now investigating a shift in scale moving from the aquifer-scale to the national-scale assessments supported by available Earth Observation science and technology.
All these initiatives imply the need for more integrated knowledge of aquifers and ground water. This knowledge is still lacking.
Nonetheless, the future for acquiring data and knowledge on the aquifers and ground water resource of Canada looks good. Let’s hope that it is sustained!
Alfonso Rivera, PhD, is chief hydrogeologist of the Geological Survey of Canada and adjunct professor at the INRS-ETE, Université de Québec. He is the editor and author of two books: Canada’s Groundwater Resources (2014) and Regional Strategy for the Assessment and Management of the Transboundary Aquifer Systems in the Americas (2015). Dr. Rivera has published many scientific articles in journals and conference publications. He provides scientific and technical advice to institutions and governments in Canada and internationally.