All over the world, because of overuse, waste, and neglect, freshwater resources (lakes, rivers, and aquifers) are being exhausted or polluted at an alarming rate. Demand for water – for industrial, agricultural, and domestic uses – continues to rise rapidly as the global population and economy keep growing.
“Over the last three centuries, the growth in the volume of water withdrawn from freshwater sources for human use has been much more rapid than the growth in population,” reports the Geneva-based World Health Organization.
This is true in the Philippines which, despite being surrounded by bodies of water, is home to more than 100 million people.
In the 1950s, the Philippines had as much as 9,600 cubic meters of clean water per person, according to Dr. Rafael D. Guerrero, former head of the Philippine Council for Aquatic and Marine Research and Development. Four decades later, Filipinos must make do with little more than a third for that volume – 3,300 cubic meters per capita.
In “Handbook Philippines,” contributing author Sandra Volpp wrote: “There are ample freshwater reserves all over the country. One-third of the available freshwater is sufficient to cover demand nationwide. But many of these reservoirs are contaminated or polluted.”
More than 400 rivers and streams have been identified in the Philippines, but “only 36% are suitable sources of potable water supply, while 60% of the groundwater is contaminated with coliform bacteria, mostly from garbage dumps,” Volpp penned. “This has led to an increase in water-borne diseases, such as cholera, diphtheria, typhoid fever, dengue fever, and amoeba infections.”
The problem is even greater in large cities. “A large number of households are not connected to canalization, so their wastes are directly channeled into rivers and the sea,” Volpp noted. “This problem is exacerbated in the big cities.”
Volpp also wrote: “Water services remain inadequate in many areas, which is why many people revert to deep wells. This leads to a sinking groundwater level, to increased salinity, and ultimately, to a shortage of potable water.”
A looming water crisis is in the offing! “We cannot talk of providing sustainable water to the people unless we protect the sources of the commodity – the watersheds,” Elisea Gozun, former head of the Department of Environment and Natural Resources (DENR), once pointed out.
“Without vegetative cover, especially the trees, the land’s water absorption capacity is greatly reduced,” contends Ines Basaen who, at the time she spoke those words, was the national coordinator of the International Labor Organization’s community-based environment impact assessment for indigenous people’s project.
Some people believe that if the forest disappears, so will the life of people. Without trees, there will be no water. And if there is no water, there will be no life. So one wonders: Do trees really produce water?
“You ask an interesting question,” said Dr. Patrick B. Durst, who was senior forestry officer with the regional office of the UN Food and Agriculture Organization (FAO) in Bangkok, when this author interviewed him. “As with so many things related to forests and trees, the answer is not simple – certainly not as simple as many people would like to present it.”
According to Durst, trees are not a source of water “in the narrow sense.” “In fact, as living organisms, trees are substantial consumers of water, particularly when growing healthily,” he explained. “That is why, for example, people sometimes plant fast-growing trees to help drain swamps; the trees consume water and draw down the water level.
“Conversely,” he continued, “water tables sometimes rise when trees are cleared from an area. Famous watershed studies at the Coweeta Hydrological Laboratory in North Carolina, conducted since 1934, show very clearly that there was a scope for increased water yield by reducing forest vegetation.”
Water use by trees is also at the heart of the argument of many against the use of eucalyptus trees. In 1990, an estimated 10 million hectares, or approximately one-quarter of tropical forest plantations, were planted with eucalyptus. More than half of these were located in tropical Asia, including the Philippines.
“As a fast-growing species, eucalyptus uses a lot of water and may contribute to a lowering of water tables,” Dr. Durst argued. “The same is true of most fast-growing tree species. It seems, not illogically, that you need a lot of water to produce a lot of wood quickly.”
So, what role do trees play in “producing” water?
Clearly, trees must be good for something it comes to watershed management, or else foresters and water management specialists wouldn’t make so much fuss about trees.
Here’s Dr. Durst again: “The answer is that trees (and more importantly healthy forests) are very important. The main benefit they provide is helping to intercept precipitation and facilitate its infiltration into the soil and ground water storage areas.”
Leaves, branches and other parts of trees intercept rainfall. Healthy forests’ ground cover – organic litter, twigs, small plants and fallen leaves, among others – help trap water and hold it until it has an opportunity to soak into the ground soil.
In addition, roots whether alive or decaying, provide additional pore space above that of normal soil texture for water to infiltrate into the ground. This is the reason why local springs and streams maintain a healthy flow when surrounded by protected micro-watersheds.
Next to air, water is the element most necessary for survival. You may not know it, but water makes up more than 60 percent of our body weight. Proteins make up only 18% while fats encompass 15%, minerals 4%, carbohydrates 2% and vitamins less than one percent.
A person needs at least 24 liters of water daily or one liter per hour. Even when he breathes, he still needs water. “Our lungs must be moist to take in oxygen and excrete carbon dioxide,” wrote Leroy Perry in a Reader’s Digest article. “It is possible to lose half a liter of liquid each day just by exhaling.”
As water becomes more scarce, conflict over water rights are inevitable. “Wars will be fought over water,” World Bank’s Ismael Serageldin once pointed out.
