At a national seminar towards the end of November on Acquifer Mapping and Ground Water Management, Union Water Resources Minister, Uma Bharati, has called for serious efforts towards better ground water management.

The Centre has reportedly formed a Committee to suggest methods to conserve the fast depleting ground water levels through acquifer recharge. The government, it is learnt, intends to introduce a draft model law to address the issues relating to conservation of ground, surface and rain water.

Rain, a gift of Nature, is man's main source of sweet water for sustenance of life on earth. The rain falls on land and through the tributary streams, it flows into the rivers which drain into seas to keep the earth dry and habitable. Rain water is not only preserved in surface storage, but is also stored in acquiferous strata that exists below the ground surface through absorption. 

The capacity of the land to absorb rain water depends on their multiple characteristics such as ground slope, soil conditions, forest cover, topography and additionally on natural factors such as temperature and wind during rainfall.

When capacities of rivers at any point are inadequate to contain the volume of rainwater, they overflow the adjoining banks resulting in floods. To counter this phenomenon, protective side embankments are constructed to contain river flows and save the land. However, floods still occur whenever and wherever these embankments are breached.

Incidentally, the traditional river embankments are made of earth which, when damp during the monsoon, is least resistant and very vulnerable to breaches due to the onslaught of river water. Dams have been constructed at the heads of major rivers and barrages at intermediate locations to preserve excess rainwater and control floods.

Ironically, the cubatures of these water storage methods are depleted annually due to siltation caused by rainwater runoff over the denuded catchment land surfaces. This is an effect of deforestation and transporting the eroded surface soil into the rivers/reservoirs. During heavy rain these dams and barrages are forced to release water for their safety and thus become the instrument of floods instead of their control.

This is happening for lack of maintenance of capacities of rivers/reservoirs by resuscitation to retain their designed holding power. If during such releases there is incessant rain in the catchment areas and the river embankments at vulnerable points are breached, the result could be catastrophic floods. Ultimately, the sweet rain water flows into the sea and gets wasted.

The vicious cycle of wastage of rainwater in the Bay of Bengal and the Arabian Sea has become an annual phenomenon every monsoon. This has again led to a rise in arsenic/fluoride concentration in underground water for lack of adequate recharge of their acquifer, thus making nature's gift of sweet water unfit for consumption. Flood prevention and rain water preservation are correlated and need be tackled at the root.

The major factors responsible for floods are the reduction in the capacities of dams and reservoirs. Earthen river embankments are vulnerable to breaches during the monsoon.

The immediate remedy lies in replacement of traditional earthen embankments by breach resistant reinforced ones. This will stop transportation of the eroded surface soil of denuded catchments into the rivers, that cause bed siltation and reduction of their flow capacity.

The entire catchment rain will thus be retained on the respective lands for harvesting in surface storage and underground water recharge systems. It will, however, require resuscitation of all local ponds, tanks as well as excavation of additional water bodies deep enough to preserve the full quantum of rain.

These water bodies will also help to dampen the runoff velocities, reduce surface soil erosion and act as silt traps to ensure that the eroded soil remains within the locality. Annual maintenance of these water bodies by removing deposited silt is also imperative.

Wells fitted with strainers can be dug in these water bodies at appropriate locations to recharge the acquifers below as being mapped by the government. This will reduce the percentage of arsenic/fluoride in the water and make the underground water potable.

Tubewells form the main infrastructure for drinking water supply in rural India. Unless potable water is supplied to people, the country's labour force will be the victims of stunted growth. The workers will also be vulnerable to various ailments. In the net, this will reduce production and impede the country's development.

It is reassuring to learn from a Letter to the Editor, titled "Riverine Issues" (The Statesman, October 17) by Prof Desai of the Civil Engineering Department of IIT Kharagpur which mentions that the design of artificial groundwater recharge structures like relief wells/sub surface dykes, and breach resistant reinforced earthen embankment technology uses precast concrete materials as reinforcements inside earthen bunds.

The concrete materials are manually useable and as such the technology is simple and oriented towards rural employment. It can, therefore, be used by villagers under the Mahatma Gandhi National Rural Employment Guarantee Act to enable them to construct and maintain their own flood protection structures.

With the reinforced embankment technology devised by IIT Kharagpur, the vulnerability of earthen bunds to breaches can be checked. It wil now be possible for the new committee, under the Water Resources Ministry, to formulate comprehensive plans for rainwater preservation and flood management to augment better quality water resources and sustain the health of the nation.

Sluice gates at appropriate points of the reinforced embankments can help draw the excess river water that flows into lands. This can facilitate harvesting and ensure minimum wastage of nature's gift into the seas ~ a phenomenon that was once lamented by Mahatma Gandhi.