A translation by Judith Turcotte
In my previous blog, I described the dangers that threatened the largest basin of freshwater created by the Great lakes and the St. Lawrence River. In this same blog, I wondered about other sources of drinking water.
DESALINATION
The ocean water represents 97% of the water on the planet; however, this salt water is unsafe for consumption and agricultural irrigation. Its desalination could become a solution with high potential since 40% of the population of the planet lives at least 100 km from the sea. The desalination of the ocean water is costly and only 300 million people (less than 4% of the global population) depend on the desalination of ocean water for drinking water, according to the International Desalination Association (IDA). Considering the very high cost of a desalination plant, it should not be surprising that Saudi Arabia and the United Arab Emirates top the list. We find, on a small scale, desalination plants in Europe and in the Southern states.
Desalination has an impact on the environment because it demands a lot of energy and water. The use of this drinking water production technique therefore remains marginal.
WATER TABLE
A recent study published in the review Nature shows that the underground water supply has seen an important decline in the last few years. The study covers 40 countries and the underground water studied represents 75% of the underground water in the world. This decline is explained by a decrease in precipitation and the agricultural growth that depends on the underground water for its irrigation.
In Québec, at the turn of the century, very little was known of the underground water yet 25% of the Québec population depended on it for their drinking water. Montréal has a water table but does not use it for its drinking water supply. The level of the water is large enough to kayak and is accessible by entering through a cave situated in Saint Léonard.
AQUIFER
An aquifer is an underground layer of porous and permeable rocks which water can infiltrate. The underground water is the most important resource of drinking water. It feeds 20% of the Québec population and contrary to surface water, it is not necessary to treat it before consuming it. This water comes to us from precipitation and snowmelt. The sources of drinking water are nevertheless susceptible to drought caused by climate change and to pollution caused by chemical fertilizer used in agriculture.
In a previous blog, I referred to the possibility of seeing the construction of canals and pipelines to deliver the water of the Great Lakes to the Southern states. The idea is not far-fetched and was considered in Canada.
GRAND CANAL
The Grand Recycling and Northern Development Canal also known as the Grand Canal consisted of a project to retrieve the freshwater from the rivers which flowed into Hudson Bay. The idea was to create dams to prevent freshwater from reaching salt water. A large freshwater lake would therefore be created and a pipeline network would direct this water towards Georgian Bay to raise the level of the Great Lakes. This same water would then be directed towards the Southern states.
Not so long ago, in 1985, the project had interested Robert Bourassa, the premier of Québec and Brian Mulroney, the Prime Minister of Canada. Large engineering firms had supported the concept. However the fear of a negative impact on the environment prevented the project from proceeding.
Climate change may cause problems with our supply of drinking water and desperate situations call for desperate measures. That solution may come back.