New Water Sources Won't Quench the World's ThirstBy
Kenya’s government announced last week the discovery of two huge aquifers in drought-stricken areas in the north of the country. The underground water sources reported in Turkana contain at least 250 billion cubic meters of water. The revelation has raised hopes of more such finds in Africa; like oil (also discovered in Turkana), new aquifers are being discovered across the continent. Analysis suggests that underground water volumes in the region equal about 100 times the amount of water found on the surface.
Yet the discovery of these new aquifers won’t have much impact unless the world takes measures to ensure more effective access to, and use of, the water sources we already have. Even for Kenyans, a new aquifer in one part of the country isn’t that much help. For some people in rural Turkana, the new find will help simplify access to clean water by providing nearby boreholes. But the country’s annual freshwater withdrawal from lakes, aquifers, and rivers is 2.7 billion cubic meters, compared to close to 21 billion cubic meters in renewable supplies. For most of Kenya (and the rest of Africa), the most pressing problem isn’t a countrywide lack of water; it’s the lack of immediate, reliable access to it.
UNESCO, the UN body that helped finance the survey work behind the Turkana aquifer, notes that 40 percent of Kenya’s 41 million people don’t have access to safe water, and 28 million lack adequate sanitation. Even those lucky enough to have access face problems: In Kenya’s capital Nairobi, for example, taps frequently run dry when pumps fail—which, in turn, lets pollution seep into old, damaged pipes. When the pumps start working again, what comes out of the tap can be very dangerous to your health.
The urban challenge, then, is extending and improving the infrastructure for quality networked supply, by digging trenches, laying pipes, and building water and sewage treatment plants—which is expensive and difficult. There is a similar problem for rural agriculture: Less than two percent of Kenya’s agricultural land is irrigated. The high cost of boreholes, pumps, pipes and irrigation channels has deterred rollout even in areas that already had access to water supplies.
Were Kenyan farms irrigated and fertilized, that would increase grain yields only from 0.5 metric tons per hectare to from 1.5 to 2 tons. By comparison, U.S. grain yields are closer to 7 tons a hectare. A big factor accounting for the difference: far higher investments in equipment and infrastructure on and off the farm. Without that supporting infrastructure, the return to irrigation investments is far lower. Reliable water access is necessary—but on its own, it’s an insufficient condition for productive farming.
For all of its agricultural productivity, the U.S. is hardly a model when it comes to sustainable water use. The Turkana aquifer volume equals 70 years of Kenya’s current freshwater withdrawals. If Kenyans sucked up water at the same rate per person as Americans do (largely to support farming), the new resources would equal just four years of the country’s withdrawal. In U.S. western states, historical water rights have led to a situation by which desert farms in California are growing alfalfa for export to China, where it is used to feed cows. The electricity required to process and deliver water to those farms is about 2.5 kilowatt hours per cubic meter. That’s more electricity than is required to take seawater and use reverse osmosis to desalinate it for human consumption. Charging farmers the full cost of producing the water they use would amount to a step toward greater efficiency–alongside infrastructure repairs, drip irrigation, no-till approaches, and drought-resistant crops.
As many as 2.7 billion people (PDF) live in river basin areas where there is severe water scarcity during at least one month of the year. As the global climate changes and populations grow in numbers and wealth, that number could climb. More discoveries such as that of Turkana’s aquifers will relieve pressure on local freshwater supplies. But only investments in ensuring water access while improving the efficiency of water use will lead to a world of sustainable, equitable, and productive water consumption.