the water myth the myth of abundance: Canadaâ€™s Freshwater Supply
The Water Myth The Myth of Abundance: Canadaâ€™s Freshwater Supply design by // Onice Mejia photo credit // flickr.com
The Abun C Fres
Myth of ndance: Canadaâ€™s eshwater Supply
Water for Canadian Aboriginal peoples was the basis of all life. At the beginning of time, the Creator gave instructions to Aboriginal peoples to respect water, air, and the earth by keeping it pure. Northwest Coast Indians located village sites on key rivers and shores. Totems poles were their vivid expressions of their respect and dependence on the land, water and sky. The Inuit of Canada’s North also had a special relationship with water and ice. They derived a great deal of their sustenance from it—seals and fish remain the mainstay of many traditional Inuit diets. In the long dark winter, villages were established on or near the ice to provide ready access to this food source. In the spring and summer, they fished for trout in inland lakes and rivers. During the period of European colonization, the rivers carried furs, trade goods, and explorers, heralding the influx of settlers into the wilderness. The arrangement of streams and rivers flowing into Hudson Bay and into the Mackenzie and St. Lawrence Rivers permitted canoes to travel west and north across the length and breadth of the land that became Canada. Seven years before Canada became a nation, one of the most eloquent of the Fathers of Confederation, Thomas D’Arcy McGee, spoke of the link between water and people:
I see within the round of that shield the peaks of the Western Mountains and the crests of the Eastern waves—the winding Assiniboine, the five-fold lakes, the St. Lawrence, the Ottawa, the Saguenay, the St. John, and the Basin of Minas—by all these flowing waters in all the valleys they fertilize, in all the cities they visit in their courses, I see a generation of industrious, contented, moral men ... worthy ofzsuch a country.1
1 D’Arcy McGee, Thomas. Speech made in the Legislative Assembly, May 2, 1860. As quoted in Canadian Literature: The Beginnings to the 20th Century, ed. Catherine M. McLay (Toronto: McClelland and Stewart Ltd., 1974), p. 181.
the percentage of the worldâ€™s freshwater supply that is in Canada, which recently banned bulk exports of water
The apparent abundance of Canadian water must have appeared limitless to our European forefathers, coming from the crowded urban areas of England and France. Indeed, compared to most other nations, Canada is well endowed with fresh water. We have been blessed with a storehouse of water that was deposited in our lakes over 10,000 years ago by retreating glaciers. Almost nine percent, or 891,163 km2 of our land surface is covered with lakes, more than that of any other country. Wetlands increase this figure to 25%. Canada shares with the United States five of the world’s largest lakes, the Great Lakes. These collectively hold more water than all other lakes on earth. Almost nine percent of the world’s yearly runoff flows in Canadian rivers, ranking us behind only Brazil and Russia. To put Canada’s water wealth in perspective, Canada’s river flows alone could provide each Canadian with 360,000 litres per day, enough to fill 6,300 bathtubs. The second most water-wealthy nation, Brazil, has less than half the river flow water per capita that Canada does—roughly 3000 bathtubs per person.
The amount of water on this planet is prodigious. Current estimates place the global supply at about 1.3 billion cubic kilometers (a cubic kilometer would fill 300 Olympic stadiums). However, most of this immense volume is either salty or permanently frozen. Only a tiny fraction—one tenth of one percent—is available as a source of fresh water for plants, animals and humans. This is still a sizeable volume: about 125,000 cubic kilometers, enough to fill 600 bathtubs for every human being on earth. Over time, the perception that the world and especially Canada are blessed with an abundance of fresh water has led to misuse and abuse of the resource: from household toilets that use 18 litres per flush where 6 litres would do, to industrial plants—and some municipalities—that use water bodies as convenient sewers. In 1999, the average Canadian daily domestic use of fresh water per capita was 343 litres, second only to that of the United States of America. Now, in the 21st century, Canadians must start thinking about water in a manner more closely resembling Canadian Aboriginal’s respect and dependence on this precious resource. Though water is considered a renewable resource, “renewable” refers only to that portion that circulates back and forth in the hydrologic cycle. Pressures on the resource are growing. For example, between 1972 and 1996, Canada’s rate of water withdrawals increased by almost 90%, from 24 billion m3/yr (cubic metres per year) to 45 billion m3/yr. But, our population increased by only 33.6% over the same period, illustrating the growth in our thirsty lifestyles. As the readily available supplies of fresh water are being used up, we begin to see that there are real limits to how much water we have.
T H C
The Hydrologic Cycle:
the Power of the Sun
The endless circulation of water from the atmosphere to the earth and its return to the atmosphere through condensation, precipitation, evaporation and transpiration is called the hydrologic cycle. Heating of the ocean water by the sun is the key process that keeps the hydrologic cycle in motion. Water evaporates, then falls as precipitation in the form of rain, hail, snow, sleet, drizzle or fog. On its way to earth some precipitation may evaporate or, when it falls over land, be intercepted by vegetation before reaching the ground. The cycle continues in three different ways: • Evaporation/transpiration: on average, as much as 40% of precipitation in Canada is evaporated or transpired. • Percolation into the ground: water moves downward through cracks and pores in soil and rocks to the water table. Water can move back up by capillary action or it can move vertically or horizontally under the earth’s surface until it re-enters a surface water system. • Surface runoff: water runs overland into nearby streams and lakes; the steeper the land and the less porous the soil, the greater the runoff. Overland flow is particularly visible in urbanareas. Rivers join each other and eventually form one major river that carries all of the sub-basins’ runoff into the ocean.
Although the hydrologic cycle balances what goes up with what comes down, one phase of the cycle is “frozen” in the colder regions during the winter season. During the Canadian winter, for example, most of the precipitation is simply stored as snow or ice on the ground. Later, during the spring melt, huge quantities of water are released quickly, which results in heavy spring runoff and flooding.
Parts of the cycle 10
Freshwater fish stocks have declined by up to 90% in many of the worldâ€™s largest rivers.
EVAPORATION • As water is heated by the sun, it’s surface molecules become sufficiently energized to break free of the attractive force binding them together, and then evaporate and rise as invisible vapour in the atmosphere. Evaporation can be from bodies of water or soil
TRANSPIRATION • Water vapour is also emitted from plant leaves by a process called Every day an actively growing plant transpires five to 10 times as much water as it can hold at once.
CONDENSATION • As water vapour rises, it cools and eventually condenses, usually on tiny particles of dust in the air. When it condenses, it becomes a liquid again or turns directly into a solid (ice, hail or snow). These water particles then collect and form clouds.
PRECIPITATION • Precipitation in the form of rain, snow and hail comes from clouds. Clouds move around the world, propelled by air currents. For instance, when they rise over mountain ranges, they cool, becoming so saturated with water that water begins to fall as rain, snow or hail, depending on the temperature of the surrounding air.
RUNOFF • Excessive rain or snowmelt can produce overland flow to creeks and ditches. Runoff is visible flow of water in rivers, creeks and lakes as the water stored in the basin drains out.
PERCOLATION • Some of the precipitation and snow melt moves downwards, percolates or infiltrates through cracks, joints and pores in soil and rocks until it reaches the water table where it becomes groundwater.
GROUNDWATER • Subterranean water is held in cracks and pore spaces. Depending on the geology, the groundwater can flow to support streams. It can also be tapped by wells. Some groundwater is very old and may have been there for thousands of years.
WATER TABLE • The water table is the level at which water stands in a shallow well.
Limiting Factors Although Canada has a significant amount of fresh water, we possess only seven percent of the world’s renewable freshwater supply. For example, 99% of the Great Lakes’ total volume is fossil water from ancient melted glaciers. Only one percent of their volume is replenished through the hydrologic cycle.
+ People already use over half the world’s accessible freshwater, and may use nearly three-quarters by 2025.
In Canada, 84% of the population lives in a narrow southern band, while 60% of our water supply flows north to the Arctic Circle. Several of our largest lakes (Lake Winnipeg and Lake Winnipegosis in Manitoba and Great Slave Lake and Great Bear Lake in the Northwest Territories, for example) are far from urban centers, requiring diverting and dams to bring the water to the population.
Our growing population, and our growing thirst for water, are being concentrated in expanding metropolitan areas, and are forcing water regulators and policy makers to find ways to stretch available supplies even further.
Because our water use almost always leads to some degree of deterioration in water quality, the less water we withdraw, the less we upset the natural balance of our aquatic ecosystems. And, the less we upset the ecosystem, the less we have to spend to restore the water quality to an acceptable standard for public use.
Increasing pollution of surface and groundwater is further reducing the supplies of readily available, clean water.
Finally, financing by municipal governments for the treatment of water supplies and wastewater is becoming increasingly constrained.
We can, however, make a significant contribution to solving these problems by reducing unnecessary levels of water use. This is called water conservation. Simply stated, water conservation means doing the same with less, by using water more efficiently or reducing where appropriate, in order to protect the resource now, and for the future. To do so requires that we identify the areas within our homes, businesses, buildings and processes where we waste water and then make appropriate changes, either in our fixtures, or in our water-using habits. In our homes, with little change to the way we do things now or the equipment we use, we can reduce water consumption in the home by 40% or more.
the minimum number of gallons (about 19 litres) of water needed to meet a personâ€™s needs, according to the World Health Organization
In the Kitchen • Use an aerator and/or a water • When boiling vegetables, save flow-reducer attachment on your water by using just enough to tap to reduce your water usage. cover them and use a tightly fitting lid. • Always turn taps off tightly so they do not drip.
• When cleaning fruit and vegetables, never do so under a continuously running tap. Wash • Promptly repair any leaks in and them in a partially filled sink and around your taps. (One leak can then rinse them quickly under waste several thousand litres of the tap. water per year.) • When hand-washing dishes, never run water continuously. Wash dishes in a partially filled sink and then rinse them using the spray attachment on your tap.
• Keep a bottle of drinking water in your refrigerator instead of running your tap until the water gets cool each time you want some water. Do not forget to rinse the container and renew the water every two to three days.
• If you have an electric dishwasher, use it only to wash full loads, and use the shortest cycle possible. Many dishwashers have a conserver/water-miser cycle.
In the bathroom About 65% of indoor home water use occurs in our bathrooms, and toilets are the single greatest water users.
• When washing or shaving, partially fill the sink and use that water rather than running the tap continuously. (This saves about 60% of the water normally used.) Use short bursts of water to clean razors. • When brushing your teeth, turn the water off while you are actually brushing instead of running it continuously. Then use the tap again for rinsing and use short bursts of water for cleaning your brush. (This saves about 80% of the water normally used.) • Always turn taps off tightly so they do not drip. • Promptly repair any leaks in and around taps. • Use aerators and/or water flow-reducer devices on all your taps. • Use either low-flow shower heads or adjustable flow-reducer devices on your shower heads. (They reduce flow by at least 25%.) • Take short showers. Turn off the water while you are soaping and shampooing and then rinse off quickly. Some shower heads have a shut-off lever that allows you to maintain the water pressure and temperature when you stop the flow.
Asian rivers are the most polluted in the world, with three times as many bacteria from human waste as the global average. These rivers have 20 times more lead than those of industrialized countries.
• Short showers use less water than baths, but if you still prefer bathing, avoid overfilling the tub. • Reduce water usage by about 20% by placing a weighted plastic bottle filled with water in the water tank of your toilet. Low-cost “inserts” for the toilet tank are an alternative to plastic bottles. With a toilet insert, a family of four could save 45 000 litres of water per year. Toilet inserts are available at most hardware and plumbing supply stores.
1.1 billion -- the number of people worldwide who lack an adequate and safe supply of water for their daily needs, approx. one in five.
• You can reduce water usage by 40% to 50% by installing low-flush toilets.
• Flush your toilet only when really necessary. Never use the toilet as a garbage can to dispose of cigarette butts, paper tissues, etc.
• Check regularly for toilet tank leaks into the toilet bowl by putting a small amount of food colouring into the tank and observing whether it spreads to the bowl without flushing. Repair leaks promptly. Ensure that the float ball is properly adjusted so that the tank water level does not exceed the height of the overflow tube. Also, periodically examine whether the plunge ball and flapper valve in the tank are properly “seated”, and replace parts when necessary.
• Regularly check for leaks at the base of your toilet and have any promptly repaired.
• Never flush garbage of any kind down the toilet. Household cleaners, paints, solvents, pesticides, and other chemicals can be very harmful to the environment. And paper diapers, dental floss, plastic tampon holders, etc., can create problems at sewage treatment plants.
• Locate your water meter and periodically record the reading late in the evening and again early the next morning between any water use. Then compare the readings to see whether there was any water leakage during the night. If so, track it down and have it repaired.
In the laundry room
• Wash only full loads in your washing machine.
• Use the shortest cycle possible for washing clothes, and use the “suds-saver” feature if your machine has one. • If your washer has an adjustable water-level indicator, set the dial to use only as much water as is really necessary.
• If you have a septic system, spread out your washing to avoid heavy-use days that could overload the system.
• Use only cleaning products that will not harm the environment when they are washed away after use. Look for “environmentally friendly” products when shopping.
• Promptly repair any leaks around the taps, hoses, or fittings of your washer, or the taps of your laundry sink.
The importance of protecting our water resource cannot be overstated. In economic terms, the measurable contribution of water to the Canadian economy is difficult to estimate. In environmental terms, water is the lifeblood of the planet. Without a steady supply of clean, fresh water, all life, including human, would cease to exist.
The Global Water Supply Estimates vary, but of all the water on earth, only a tiny fraction— just a few hundredths of a percent—is readily available as a supply of fresh water for plants and animals.
World’s Total Water • 1,420,240,000 km3
% 1 . 5 9
• 95.1% Oceans and Inland Seas • 4.9% Fresh Water
Freshwater • 70,137,000 km3 • 68.5% Underground and Soil Moisture
• 31.4% Polar Ice Caps and Glaciers
• 0.02% Surface and Atmosphere • 0.0001% In Plants and Animals
Surface and Atmospheric Water • 939,700 km3 • 71.4% Lakes • 17.6% Atmosphere • 2.0% Rivers
How Many Dams are there in Canada? Canada now ranks as one of the worldâ€™s top 10 dam builders. Although the Canadian Dam Associationâ€™s register of dams (2003) reports 933 large dams, there are many thousands of small dams. A large dam is defined as being higher than 15 metres or, under certain conditions, higher than 10 metres. In Canada, large dams are used primarily for hydroelectric power generation (596 dams), but are also used for the following purposes: