- Withdrawal Uses
- Instream Use
- We Take Water for Granted
- What is a Fair Price?
- Water Use in the Future
Water works for us in many ways, making our lives easier and more enjoyable. But we must take great care not to overuse and abuse this precious resource.
Water is a basic necessity of life, not only for people but for every type of plant and animal as well. Water accounts for about 65% of our body weight. If we lost as little as 12% of it, we would soon die.
Water is essential not only for survival but also contributes immeasurably to the quality of our lives. Since the dawn of time, human beings have harnessed water to improve their lives. In some ways, the history of civilization is the story of how we have made water work for us in ever more ingenious ways. As early as 5000 B.C., our predecessors used irrigation to increase crop production. Archaeologists have found masonry sewers dating back to 2750 B.C. and water-flushed toilets dating back almost as far.
Water played -- and continues to play -- a special role in the growth of our nation. The fur trade, which stimulated the exploration of Canada's vast interior, was totally dependent on water for transportation. Water powered the grist mills and sawmills along small and large rivers in the Maritimes and Upper Canada, making possible the production and export of grain and lumber, two early economic staples. As Canadian industry diversified, water was put to new uses: as a coolant, a solvent, a dispersant, and a source of hydroelectric energy.
Water transportation is still the most efficient way to move bulk goods. Water is also the basis of cheap energy. It is a raw material in the manufacture of chemicals, drugs, beverages, and hundreds of other products. It is an essential part of the manufacturing processes that produce everything from airplanes to zippers. In other words, we depend on water for most of our technology, comforts and conveniences, and of course for personal hygiene and to flush away our waste products.
Many people think it makes no difference how much water we use or what we use it for. Actually, the way we use water is very important. Some uses are incompatible with others. Some uses remove water from the natural cycle for longer periods than others. Worst of all, most uses actually lower the quality of the water.
Water quality is everybody's business because ultimately we all draw from the same supply of water. Most Canadians live downstream from somebody else, not to mention the fact that the same basic supply of water, replenished over and over again through the hydrologic cycle, has been used millions of times over in the long history of the earth. We are now aware of limits to the reuse of water, when and where it is returned to nature diminished in quantity and quality. Therefore, we must learn to understand water use much better: where we use it, what to measure, what the main uses are, how they compete and interfere with each other, and how to manage the growing competition.
Where we use water
The most obvious and immediate uses occur in its natural setting. They are called instream uses. Fish live in it, as do some birds and animals, at least part of the time. Hydroelectric power generation, shipping, and water-based recreation are other examples of human instream uses.
These instream uses are not always harmless. For example, oil leaking from outboard motors and freighters can cause pollution. Large reservoirs needed for hydroelectric power generation remove water by evaporation and completely change the river regime for downstream users.
The greatest number and variety of water uses occur on the land. These are called withdrawal uses. This term is appropriate because the water is withdrawn from its source (a river, lake or groundwater supply), piped or channelled to many different locations and users, and then is collected again for return to a lake, river or into the ground. Household and industrial uses, thermal and nuclear power generation, irrigation and livestock watering all fall into this category.
Most withdrawal uses "consume" some of the water, meaning less is returned to the source than was taken out. Furthermore, the water which is put back into its natural setting is often degraded. For example, water leaving our houses contains human and household wastes. The same is true of water used in many industrial processes. Often this liquid waste is only partially treated, if at all, before it is returned to nature.
Withdrawal use is directly measurable as quantities of intake, discharge, and consumption. Water intake is the amount withdrawn from the source for a particular activity over a specific period of time. This measure is important because it represents the demand imposed by that particular use on the water source at a given location. Usually, however, most of the water taken out is returned at or near the source. This is called water discharge.
Water consumption is the difference between water intake and water discharge. Consumption removes water from a river system and makes it unavailable for further use downstream. The irrigation of crops is by far the largest consumptive use, followed by evaporation in large open water reservoirs and cooling ponds. However, because evaporation is difficult to measure, it is seldom recognized as water consumption.
In the global hydrologic cycle, water is never actually lost. For example, the water evaporated from industrial cooling towers or an irrigated field simply returns to the atmosphere, later to fall again as precipitation somewhere else on earth.
We determine how efficiently we use water in a particular process or economic sector with the help of two additional measurements: gross water use and the amount of water that is recirculated. Gross water use represents the total amount of water used during a process. This would normally be equal to the water intake, except that more and more users (especially industries) reuse the same water one or more times. In such cases, the gross water use could be equal to several times the water intake. The difference between gross water use and water intake is the amount recirculated, which can be expressed as a recycling rate. This is the number of times that the water is recirculated and indicates how efficient a particular water use is.
In 2006, five main withdrawal uses are estimated to have accounted for a gross water use in Canada of 60 527 million cubic metres (MCM), made up of intake (50 914 MCM in industrial uses) and recirculation (9 622 MCM in industrial uses). About 30% of the intake was consumed (mostly industrial uses and agriculture), while the rest was discharged back to receiving waters.
See also: Water use
The following is a closer look at these water uses, starting with the largest.
- Thermal power generation: This industrial sector, which includes both conventional and nuclear power generating plants, withdrew slightly more than 63% of the total water intake in 2006. Next to fuels, water is the most important resource used in large-scale thermal power production. Production of one kilowatt-hour of electricity requires 140 litres of water for fossil fuel plants and 205 litres for nuclear power plants. Some of the water is converted to the steam which drives the generator producing the electricity. Most of the water, however, is used for condenser cooling.
Why is so much cooling necessary? Because today's processes can only convert 40% of the fuel's energy into usable electricity. The rest is wasted. This shows the double cost of inefficient energy use: first, in the wasted energy, and then in the water required to cool the wasted heat to the temperature where it can be released safely into the environment. This requires a continuous flow of cooling water circulating through the condenser. All the cooling water is therefore returned to the environment much warmer. However, the temperature can be reduced using cooling towers and other such devices.
- Manufacturing: Water is the lifeblood of industry. It is used as a raw material, a coolant, a solvent, a transport agent, and as a source of energy. An automobile coming off the assembly line, for example, will have used at least 120 000 litres of water -- 80 000 to produce its tonne of steel and 40 000 more for the actual fabrication process. Many thousands more litres of water are involved in the manufacture of its plastic, glass, fabric components. Manufacturing accounted for 15% of water withdrawals in 2006. Paper and allied products, primary metals, and chemicals were the three main industrial users.
- Municipal use: Can you imagine a city without water? We use it for drinking, cooking, and for other household needs. Water is also needed to clean our streets, fight fires, fill public swimming pools, and water lawns and gardens. Where would this water go without a sewerage system? These residential, commercial, and public uses, and the water lost from reservoirs and pipes amounted to about 9.5% of all withdrawals in Canada in 2006. This figure does not include rural areas where water use is not measured. If rural domestic uses were included, this figure would rise to about 11%.
- Agriculture: Farmers depend on water for livestock and crop production. Agriculture was the fourth largest water user in 2006, accounting for 9.5% of total withdrawals. Water is withdrawn mainly for irrigation (92.4%) and livestock watering (5.4%). Irrigation is needed mainly in the drier parts of Canada, such as the southern regions of Alberta, British Columbia, Saskatchewan, and Manitoba. Irrigation is also used in Ontario and the Maritimes for frost control. Since so much of the water intake evaporates, only a small fraction is returned to its source. This is a highly consumptive use.
- Mining: This category includes metal mining, non-metal mining, and the extraction of coal. Water is used by the mining industry to separate ore from the rock, to cool drills, to wash the ore during production, and to carry away unwanted material.
Although the mining industry had a gross use half that used in agriculture, mining accounted for only 1% of all water intake in 2006, compared to 9.5% in the agricultural sector. This was the smallest withdrawal use, but mining recirculates its water intake to a greater extent than any other sector.
Unlike withdrawal uses, instream uses cannot be measured quantitatively because the water is not removed from its natural environment. Instead, instream uses are described by certain characteristics of the water or by the benefits they provide to us and the ecosystem.
Flow rates and water levels are very important factors for instream uses. When these conditions are changed by a dam, for example, it is easy for conflicts to arise. The most common conflict is between hydroelectric development and other uses with respect of aquatic life, wildlife, water supply and water transportation. Storage of the spring freshet (a high river flow caused by rapidly melting snow) removes the natural variability of streamflows on which many life processes depend, in particular, the highly productive ecosystems of deltas, estuaries and wetlands. To make the best use of our water, all needs must be carefully assessed and taken into account.
The main instream uses are:
- Hydroelectric power generation: This water use is the principal source of electricity in Canada today. Billions of dollars have been invested in its development. With large undeveloped hydroelectric sites still available in Quebec, Newfoundland, Manitoba, British Columbia, and the territories, this form of energy development will retain its prominent position for years to come. However, the environmental and human effects to be avoided or mitigated in such large projects make them increasingly difficult and costly to plan and build.
Hydroelectric energy is produced by the force of falling water. The capacity to produce this energy is dependent on both the available flow and the height from which it falls. Building up behind a high dam, water accumulates potential energy. This is transformed into mechanical energy when the water rushes down the sluice and strikes the rotary blades of turbine. The turbine's rotation spins electromagnets which generate current in stationary coils of wire. Finally, the current is put through a transformer where the voltage is increased for long distance transmission over power lines. In Canada, hydroelectric plants satisfy 62% of electricity demands.
- Water transport: Inland waterways in Canada have historically played a major role in getting Canadian goods and raw materials to market. Some traditional uses, such as log driving, have now disappeared. However, water transport is still the most economical means of moving the bulky raw materials which are our main exports: wheat, pulp, lumber, and minerals. The main transportation waterways are the St. Lawrence River, which allows passage of ocean-going ships from the Atlantic Ocean deep into the heart of North America, nearly as far as the prairie wheat fields; the Mackenzie River, which is a vital northern transportation link; and the lower Fraser River on the Pacific Coast. Cargo in the hundreds of millions of tonnes is transported along these routes each year. Reliable and predictable lake and river levels are very important for this use.
- Freshwater fisheries: Blessed with hundreds of thousands of freshwater lakes and rivers, Canada provides some of the most spectacular sport fishing in the world. In 1995, over 4.2 million Canadians and visiting anglers took advantage of this fact, spending $7.4 billon in the process. In 1997, the freshwater fishing industry contributed $71 million to the GDP and employed 3 500 people. Moreover, coastal rivers provide spawning grounds for salmon and other fish populations which support major saltwater fisheries.
- Wildlife: Many wildlife species live in, on, or near the water and require access to it throughout their lives. Other species may not use water as their primary habitat, but it is nonetheless essential to their well-being. Watching, photographing and studying wildlife are all popular forms of recreation for Canadians. About 19% of Canadians aged 15 years and over participated in these activities as the main or as a secondary reason for their nature-related trip, according to a 1996 survey, and spent about $1.3 billion that year on them. In 1996, hunting attracted over one in twenty Canadians and accounted for about $800 million of wildlife-related spending. An additional $320 million was spent in 1996 on residential wildlife-related activities. The majority of Canadians believe that it is important to maintain abundant wildlife and to protect declining or endangered wildlife.
- Recreation: Canadians have traditionally valued opportunities for outdoor recreation and in recent years have sought the outdoors as never before. Activities such as swimming, boating, or canoeing allow us to experience the beauty of our lakes and rivers. In 1996, 27% of Canadians over 15 years of age (6.4 million) participated in these activities, spending about 92 million days on 56 million such trips. While not all outdoor recreation requires water, the presence of water tends to enhance the experience. Expenditures on water-related recreational activities and tourism also contribute billions of dollars per year to the national economy.
- Waste disposal: It has long been convenient to use lakes, rivers, and oceans as receiving bodies for human and industrial wastes. While water is capable of diluting and "digesting" society's wastes to some degree, there are limits to what even the largest body of water can absorb. The extent to which instream processes can absorb contaminants depends on factors such as the nature of the contaminant, how much of it there is compared to the volume of water, how long the contaminant stays in the water, the temperature of the water, the rate of flow. Many of our waterways are now overloaded with wastes. This problem can best be resolved by increased regulation and/or monitoring.
We Take Our Water For Granted
Because we undervalue this precious resource, we tend to overuse it and, in fact, abuse it. The apparent abundance of water is deceptive, and the capacity of our lakes and rivers -- and even of the oceans -- to purify the wastes we dump into them is much more limited than we once thought it was. There is a price for it: billions and billions of dollars to clean up or prevent pollution. It is becoming abundantly clear that water is not a free good. Sooner or later it presents us with a bill: the price of neglect. In many cases we pay less than the actual cost of processing and delivery. For example, irrigation water charges only recover about 10% of the actual costs of the service. The same is true, to a less extreme extent, for water costs to householders.
Our overuse of water begins at home. Compared to other countries, we pay very little to have water delivered to our kitchen and bathroom faucets. Nevertheless, we use more water per person than most other countries.
Source: World Commission on Water for the 21st Century, 1999. "The Poor Pay Much More for Water... Use Much Less - Often Contaminated." (www.worldcouncil.org).
Note: The World Water Commission is assembling its data from a wide variety of sources, including its own research, World Bank reports, UN data, private sector surveys, non-governmental organizations and other Internet sources. The findings are preliminary rather than definitive, but do show trends.
What is a Fair Price?
Consider for a moment the great contribution water makes to our quality of life -- indeed to life itself. Most of us rely on municipal water service, and our health depends on the quality of the water supplied. Most Canadians have been putting this service inadvertently at serious risk by not paying a sufficient price for its provision. According to the National Round Table on the Environment and Economy, unmet water and wastewater infrastructure needs in Canada were $38-49 billion in 1996, and capital costs for the following 20 years will be in the order of $70-90 billion.
There is one clear way to deal with this problem. We need to pay realistic rates for water service which are sufficient to cover their true cost. In other words, we should pay a fair price that will recover the full cost of water delivered to the tap, one that is based on actual quantity used. Those who use more water should pay more and those who use less should pay less. Experience has shown that one important result will be users recognize the real value of this resource, and will use it more efficiently and wisely.
The price Canadians pay for water varies significantly across the country. Analysis of the 2004 Municipal Water Pricing Survey prepared in 2008 indicates that the average domestic water user (assuming 25 000 litres per month) pays $1.26 for 1000 litres. This value has increased substantially in recent years from about 82 cents per 1000 litres in 1991, and nationally, now includes a waste treatment component of about 46.5%. Correcting the problem of the undervalued water resource would involve minimal change. However, in some cases, economically rational pricing would also require an increase in water metering, which in turn would reduce demand enough to postpone the need for new facilities for years, with significant savings for each year of postponement.
Even with the price, water would still be the best bargain going, compared with other liquids we consume -- and which, unlike water, are not delivered at our taps year-round. Bottled water, for example, is in great demand at $1500 for 1000 litres, or 1000 times the price for the same volume of high quality tap water!
In 2004, the average Canadian daily domestic use of fresh water was 329 litres per person. At least half of this amount is unnecessary and wasteful. Common causes of waste at home are leaking faucets, faulty plumbing, and over-use of water for watering the lawn and washing the car. Much of this waste would be reduced if we had to pay a fair price for water. As our usage becomes more efficient, we would not only produce less wastewater, we could also afford better treatment for it. In fact, wastewater usually becomes easier to treat if it is less diluted at the treatment plant, as there is less water to be removed from the sludge. The result would be multiple savings and a better environment.
The same principle applies to industrial, agricultural, and commercial users. If major industries with their own water supplies were also charged for the amount they withdraw from their source of water, reuse would increase and a more efficient use of water would result. In fact, recycling has been called an automatic solution to the water quality problem. The cleaner the discharge required by regulations, the easier and more economical it is to reuse that same water instead of pumping in fresh supplies. Realistic pricing of water for large-volume agricultural uses such as irrigation would tend to lead to greater efficiency in its use, and therefore to conservation.
Did you know?
Water Use in the Future
As time goes on, more and more water users will compete for what remains the same finite supply. This implies increases in water efficiency and conservation and doing even more to restore its quality after use. Nor is conservation restricted to only the uses of water: energy conservation, a desirable goal in itself, also contributes to water conservation. The reason is that reduced energy consumption lessens the need for electric power generation, which outranks all other water uses many times.
We must learn to use only what we need, and need what we use. In the words of one conservation slogan: "Let's keep it on tap for the future."
Paying for the accumulated deterioration of water supply and sewerage systems, and making up for the years of indifference and neglect our water resources have suffered is very much a part of the challenge to conserve water for our own use and for that of future generations. But if we do not learn from our past mistakes now, we will add to an already large environmental mortgage.
Water use data
* All industrial values are from 2005 (Statistics Canada's survey of Industrial Water Use, 2005), Municipal values are from 2006 (Environment Canada's 2006 Municipal Water and Wastewater Survey) and Agricultural values are from 2001 (Statistics Canada's Estimation of Water Use in Canadian Agriculture in 2001).
Freshwater Series A-4
Note: A resource guide, entitled Let's Not Take Water For Granted, is available to help classroom teachers of grades 5-7 use the information from the Water Fact Sheets.
Published by authority of the Minister of the Environment
© Her Majesty the Queen in Right of Canada, 2002
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