How do 6.5 million people get enough water for their daily and agricultural needs when they live in a desert? That, explained Dr. Ellen Graber at a centre for environment seminar last Wednesday, is the problem faced by Israel every day.
Graber is a researcher at Israel’s Agricultural Research Organization. She is working on a system of water sustainability to make Israel “a paradigm for semi-arid environments,” as she put it.
It’s a tall task. With a population growth rate of four per cent per year-90 per cent of them living in cities-the amount of water taken up by urban use has been steadily increasing over the past few decades. By 2020, it is estimated that urban water use will surpass agricultural use.
Not only have these been causing chronic water shortages-most notably a 2002 shortage that caused the levels of the Sea of Galilee to drop below the level of the pumps-but pollution and over-consumption have caused Israel’s underground aquifers and water supply to become contaminated with unhealthy levels of chlorides and nitrates. As Graber put it, “what you can drink depends on what you’re willing to drink.”
And yet, Israel has become a model for sustainable agriculture. Technologies such as drip irrigation systems and micro sprinklers has increased agricultural efficiency to 90 per cent. Plastic pipes with small holes are buried underground. The holes release water at a controlled rate, minimizing water losses due to evaporation and seepage.
Sewage effluent reuse has been particularly important in maintaining this agricultural efficiency, by reducing the amount of freshwater needed for irrigation. The use of marginal water in irrigation systems has increased from ten per cent to 50 per cent in recent years. The effluent itself already contains all of the nutrients needed by crops.
But using effluent has some risks, including negative effects on soil structure. The soil becomes resistant to water absorption, hindering seed germination.
Graber argued that properly treated effluent is crucial to the maintenance of Israel’s green culture, from which people in Israel derive an “intangible life quality,” by being able to grow their own food for everyday use, for instance.
Canada is also struggling with water sustainability. A recent environmental report card by the OECD (Organization for Economic Co-operation and Development) ranked Canada second-last among 30 developed countries in water use. Per capita water consumption in Canada has risen by a quarter in the last 25 years, to over 1,600 cubic metres a year. If one were to pour that much water into one-pint beer glasses and stack them up, the resulting pile would be 477 kilometres tall. Only Americans use more water per capita.
It seems Israel has a handle on sustainable agriculture; perhaps it’s time for Canada to reexamine its water usage, lest we fall into the trap of the unhappy mariner-water everywhere but ne’er a drop to drink.
