Canadian scientists are partway through a project to map underground water supplies across the country. The goal is to help policy makers prevent water shortages as industrial and urban development, along with climate change, put pressure on groundwater supplies.

'Everything's tied together. You don't exactly know how or where.'— Geoff Bleich, who relies on well water

Alfonso Rivera, chief hydrogeologist with the Geological Survey of Canada, said so far the study has found there are close to 100,000 cubic kilometres of water hidden in aquifers across the country — a large, rich supply.

But most of that is "fossil water" that was trapped underground long ago and isn't rechargeable, Rivera said. Those aquifers that can recharge do so more slowly than previously believed, and most of them aren't very deep.

"The point there is you may run out of water — they don't have a huge capacity of availability in the long run," he said.

Rivera said that up until now, Canada has had little information about how much groundwater it has, how that water is recharged and when it might run out.

Mark Hinton, a hydrogeologist with the Geological Survey who is working with Rivera on the project, said that information is important because all human activities from agriculture to the construction of subdivisions affect groundwater supplies.

"This kind of research is really useful because it helps us make decisions — how much can we use?" said Hinton, who is currently near Cornwall studying the aquifer in layers of an esker, a ribbon of sand and gravel deposited by glacier.

The overall mapping study, which started in 2003, aims to collect information about 30 major aquifers across the country.

By drilling and monitoring tiny wells, researchers can measure the speed and direction of water flow within the aquifer. They are also examining the layers of sand and clay in the soil that will influence the characteristics of groundwater in the area. In the past seven years, the study has spent $17 million gathering data on 12 of the aquifers.

The data will be used to develop computer models that decision-makers can use to forecast the effect of human use, oil and gas extraction, climate change and other factors.

Aquifers previously mapped in 1967

The last time Canada conducted a national mapping study of aquifers was in 1967, before this type of computer modelling was invented and before scientists had access to tools such as satellite imagery and airborne geophysical surveys.

'We really need to know in some detail where these aquifers flow … so that we can plan groundwater use and the potential sources that either deplete them or contaminate them.'— David Schindler, University of Alberta

The lack of information has posed a challenge in areas such as Chelsea, Que., where local residents such as Geoff Bleich rely on scarce groundwater supplies.

He is worried about a new high-density development behind his property. The municipality said it has allowed the new development to go ahead based on a study that shows there is enough water for the subdivision, provided conservation measures are taken. However, the report has been largely blacked out, allegedly to protect the privacy of the researchers and to prevent the developer from gaining a competitive advantage from the report.

Bleich is concerned because he already runs out of water if he does five loads of laundry and the dishes in sequence, he said. The water levels in his 20-metre-deep backyard well also used to dwindle when his neighbours watered their vegetable garden.

"Everything's tied together. You don't exactly know how or where."

David Schindler, a professor emeritus at the University of Alberta who studies the ecology and biogeochemistry of northern lakes and watersheds, said Rivera's study should be a source of important information.

"We really need to know in some detail where these aquifers flow and in which direction they flow so that we can plan groundwater use and the potential sources that either deplete them or contaminate them," he added.

Schindler warned that threats to groundwater, such as the oil and gas industry in the West, population growth in central Canada and climate change, are growing exponentially. Severe water shortages are possible unless decision-makers gain access to better information, he added.

U.S. studies led to laws

Schindler said the United States is already far ahead in studies of its own groundwater supplies, as sources that it has relied on have been in decline for a long time.

Studies similar to Rivera's were completed in the U.S. in the 1980s, which led to laws protecting groundwater. For example, the Great Lakes Compact signed by states bordering the Great Lakes in 2005 protects not just surface water but groundwater being diverted outside the Great Lakes Basin. That led Michigan to pass a law requiring big water users to prove their use of groundwater won't affect the rest of the water system.

No comparable laws exist in Ontario or Quebec. Rivera said he believes the lack of detailed information about Canada's groundwater so far is what is holding up the development of such laws and policies.