The vital need to save water

Water is an essential human need of which there is no viable substitute. Water is the base for food and energy security and to human and climatic health. In modern parlance, water and water resources measure a society’s spatial development, its economic growth and its environmental sustainability.

Unfortunately, the world is seeing a rapidly increasing global water deficit due to growing imbalance between demand and freshwater supply. According to the United Nations World Water Development Report 2015, while global water demand is projected to increase by 55%, the supply of freshwater is diminishing with an estimated 20% of the world’s aquifers currently over-exploited.

By 2050, global water demand is projected to increase by 55%, mainly due to the
growing demands from manufacturing, thermal electricity generation and domestic use. Expanding population and improved lifestyles, growing urbanisation and industrialisation, as well as the shift of agriculture to new high water utilisation products has exponentially pushed up the demand for water.

Unscientific methods of irrigation are creating serious shortages in these states. Efforts have been made to collect water by building storage dams and reservoirs and increasingly draining ground water through borewells and other extraction devises that have only served to further deplete shrinking ground water levels.

The solutions to water sustainability cover a range of measures such as savings in water usage to taxation as a deterrent to unfettered groundwater extraction. We would like to suggest two simple remedies that have demonstrated remarkable success in augmenting and replenishing groundwater in water challenged areas.

For urban centres, there is the simple remedy of installing and managing rainwater harvesting systems on all structures within the municipal limits. This is basically a design that carries rain water from the roof or terrace of buildings to a sufficient depth underground so as to recharge the aquifer serving the area.

The rain water harvesting co-uld be done either through voluntary social action as many resident welfare associations have demonstrated or then can be enforced through stringent regulations that make it compulsory for all buildings, residential or otherwise, to install rainwater harvesting on their premises.

Wherever ground water is extracted for urban consumption, it should be compulsory that recharge borewells should simultaneously be constructed to compensate the water taken out. This balances water equation and it has been demonstrated that wherever rainwater harvesting structures have been created, the underground water levels have gone up despite increase in population pressures and hence in demand for water.

Augmenting groundwater
Municipal and other regulatory bodies should propagate the simple technology by which rainwater can be harvested and this should be taught in schools, offices and through every available media and public information channels. In the countryside, the technique for groundwater augmentation is simpler as it is on a larger scale. This is called watershed management and protection.

Any given area of land is a natural watershed with its high and low points, its ridges and valleys. No matter how high or low a watershed is, it follows the same scientific principle. In any contour of a defined area, rainfall always travels along flow li-nes from the higher to the lower.

Every village or countryside has natural drains that carry the rainwater to lower streams, ri-vers, lakes or ponds. To recharge any given aquifer, it is only necessary to ensure that water from rainfall in that area does not flow away but goes underground to replenish the system.

Rain water has to be held back, as it were, to enable it to seep under the ground strata. This is done through water structures such as check dams that impede the flow of water to prevent it draining away. A check dam is not a device for creating a storage reservoir, that would require completely different specifications and even locales. The only purpose of a check dam is to hold water flow long enough for it to percolate the sub-strata to recharge the aquifer. This it does with immense efficiency. Billions of litres of water have been saved using these methods and result in water-starved terrain has been truly amazing.

Watershed development embraces a whole gamut of activity including gully plugging, prevention of soil erosion and silting, afforestation, repair and rejuvenation of existing water structures. Even so, this is the surest way of combating water stress and, in the long run, the only known technique for saving water for a thirsty world.

(The writer is CEO, Anandana, Coca-Cola India Foundation)