Water Technologies Somewhat to the Rescue

We found the little beetle just after sunup near the top of a dune, some 40 miles from the sea. It was already 93 degrees Fahrenheit, and the little creature, a kind of scarab, was standing on its forelegs, its back to the coastal breezes, its hindquarters waving feebly in the air, though whether to help it maintain balance I couldn't tell. My guide, a lanky Afrikaner called Piet Pieterse, interposed his hand between the sun and the beetle, and the little creature flopped over, indignantly I thought, and then, when the shadow disappeared, resumed its precarious balancing act.

Nothing much seemed to be happening -- it just teetered there, on its head -- but later in the labs of the nearby Gobabeb Research Station, Pieterse showed me a similar beetle's back, which was pitted with tiny runnels like erosion channels. Which, in a way, they were: This is the Namib's fog-collecting beetle. Those little runnels condense the fog coming in from the chilly Benguella Current and direct it to the orifice the beetle uses to keep itself moist and alive.

The Namib Desert is one of the oldest continuous deserts on earth, and in it a dazzling array of creatures has evolved, with idiosyncratic adaptations to the extreme heat and dryness: a lizard that hops from foot to foot to diffuse heat absorption; a beetle that curls into a ball to roll down dunes to conserve energy; a spider that spins a small cone-shaped web to track and condense dew; and this fog-collector beetle. Scientists at the Gobabeb institute, appropriately situated between Namibia's sand and rock deserts, have spent years studying and mimicking these ingenious inventions. The institute has, for example, learned how to take drip irrigation one step further, refining tiny emitters that carry droplets of water directly to the roots of plants. They've copied the cone-spider, to produce mesh "fog traps" whose yield is between 4 and 25 cups of water a day (depending on altitude and distance from the sea). They have also developed solar distillers to sweeten saline waters. A pilot project in South Africa, in the Soutpansberg mountains, has yielded 5 cups of water per square yard of fog-collecting mesh per day, and the test project produced enough freshwater to supply the needs of a local school.

One obvious large-scale solution to the crisis of water supply is to fetch water from elsewhere through massive water diversions, as California does each year, moving some 14 trillion gallons to its more arid south. Water diversions have been the solution of choice since human civilizations began. The technology may have been primitive, but the thinking of the early hydrological engineers such as Idrisi of ancient Egypt was, even by modern standards, remarkably sophisticated. What has changed in modern times are the fabrication technologies and the sheer scale of the diversions contemplated. China, for example, is attempting to re-engineer the whole country by massive diversions to its arid north from "surplus" Yangtze water. The Three Gorges Dam is only the start of this grandiose plan.

Another popular solution is to "make" more freshwater. Desalination is still controversial because its most popular technique, called reverse osmosis, needs large amounts of energy to essentially force water through nano-sized filter membranes. It remains, however, the best short- to medium-term solution to increasing supplies, and it has the added benefit of being able to clear up saline or brackish water where the water tables are contaminated.

Current desal technologies range from a hand-held device invented by a Canadian engineer, Bowie Keefer (it looks rather like a large nutcracker), to massive plants such as the Israeli one at Ashkelon, powered by burning fossil fuels. The Israelis have also recently green-lighted the so-called Red-Dead canal project, which involves pumping water from the Red Sea over an escarpment and then using its gravity-imposed drop to the Dead Sea to generate the power to desalinate it on the way down. In the middle are dozens of midsize projects, ranging from solar-power household stills to portable units to supply whole villages in the desert.

Desal produces clean, drinkable water -- but also a highly concentrated saline brine whose disposal poses considerable problems; coastal desal plants can radically change local ecologies by altering the salinity of the in-shore seawater. Overall, however, disposal in the oceans would have little overall effect on oceanic salinity -- the sea was the source of the salt in the first place, after all, and the balance is retained by rainwater.

Technology can help reduce water consumption, too. The Israelis have been famously efficient at deploying drip irrigation, low-pressure spray irrigation, wind-trap funnels for moisture control, cloud-seeding, and the rest of the panoply of arid-region remedies. The Jacob Blaustein Laboratory has invented a hothouse cultivation technique, closed-cycle hydroculture where evaporation is recycled and only thimblefuls of water are wasted. Drip irrigation, a name that is self-explanatory, has always been associated with wealthy farmers and high-value crops, because it has been capital intensive. But new drip systems aimed at farmers of modest means are showing promise as well.

Low-pressure spraying, which can be used for feed-grain crops, consumes 30 percent less water than conventional high spraying, and 60 percent less than conventional furrow irrigation. Laser leveling of fields has reduced irrigation water consumption considerably, in parts of California's Central Valley by as much as one-third. In the Sacramento Valley, rice farmers have done even better, with protective screens on river diversions and the development of less water-intensive crop varieties.

Small-scale actions often help. In Tegucigalpa, Honduras, a program based on the creation of community-level water boards to install and run slum services has reduced the community's water expenditures from 40 percent to 4 percent of household income. In Karachi, Pakistan, the installation of what its organizers called a "donkey system, not a racehorse system" of sewerage brought sanitary sewers to more than 600,000 slum dwellers who had been written off by politicians.

South African engineers have come up with an elegant and ingenious system for pumping water from moderately deep aquifers without diesel pumps or unnecessary power consumption: They have developed something they call "play pumps," which bring water to storage tanks through the energy of children, playing on an old-fashioned merry-go-round, whose circular motion, propelled by delightedly shrieking kids during school recess, acts as the pump.

The pour-flush toilet, flushed manually with half a gallon of water, is being installed in dozens of Asian cities, saving somewhere between 1 gallon and 5 gallons per flush. UNESCO has developed a "VIP latrine," a hygienic version of the old pit latrine, that is solidly constructed, odorless, and easy to clean. An engineer in Windhoek, Namibia's capital, turned a faucet and filled a glass of water, offering it to me to drink. I looked at it dubiously, but it was quite clear. Windhoek was, and still is, the only substantial city anywhere to fully recycle all of its wastewater, including sewage, into drinking water. And it is safe -- this is the most tested and monitored water in the world.

Often in the water world, large changes can be made with simple, no-cost policy decisions. A remarkable example comes from the African country of Niger, one of the poorest countries on Earth. Satellite images show that Niger is considerably greener than it was 30 years ago, something achieved without large-scale plantings or massive foreign aid. From colonial times all forests, and even individual trees, had been regarded as government property, which gave farmers little incentive to protect them. Indeed, most were cut down for fuel. So Niger's government turned ownership over to the peasant smallholders, who could now make a little money by selling branches, pods, fruit, and even bark. Because these sales are more lucrative over time than chopping down the trees, the trees are preserved and their growth encouraged. The ecological benefits are obvious: The trees fix the soil in place, preventing wind erosion, and they hold water. A few million acres is not enough to change the regional climate, but three times that amount might be.

In the end, it all comes down to an understanding of how interconnected natural systems are. Go and see for yourself. Ask the local people. Then apply what works.

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