Kochi April 4 In Kerala, the land of rivers, lakes and backwaters, drinking water has, of late, become a scarce commodity in several areas where the households have to buy it daily from suppliers.

It has become a booming business. For supplying 500 litres of drinking water daily for one month Rs 950 to 1,200 is charged, depending on the distance involved. As the summer aggravates, suppliers often find it difficult to meet the demand, said a tanker operator.

Depletion of groundwater as a result of indiscriminate sand mining on riverbeds has dried up the wells not only in houses but also the pumping wells of the Kerala Water Authority in highlands on the banks of rivers such as the Pampa, Manimala and Achankovil in Pathanamthitta district. This year the situation has been further aggravated by the drought conditions.

"Normally, we get 10 to 15 per cent of the total rains during the summer months," said Mr N.K.S. Nair, General Secretary, Pampa Parirakshana Samithi. But, this year it has been totally absent.

Sand mining has changed the facet of these rivers. The flat sandy riverbeds on which clean water used to flow like a sheet of glass, spread across the banks until a decade ago, is now patches of water pools and small islands of grass and bushes. In Manimala and Achankovil, the water flow has been broken while in Pampa it flows like a small stream because of the discharge from the hydroelectric project at Moozhiyar.

The wells of Kerala Water Authority at several places in the rivers do not have enough water following the sharp fall in the riverbed by 2 to 3 metres.

As a result, the pumping of drinking water in most of the panchayats at present is done only once in a week and that does not meet the daily requirement of households, Mr Jagan Mohan Das, a social activist in Kottathur in Pathanamthitta district, told Business Line.

The Kanjeetukara drinking water project in Ayroor Panchayat, which was commissioned in 1992, is a typical example, he said. The well, which used to be close to the riverbed in the past, is much above it now following indiscriminate sand mining.

Environmental degradation

Normal monsoon season in Kerala is from June 1 to November 30 and the State used to receive on an average 3,000 mm of rainfall. Until a decade ago the water table used to remain at higher levels up to March. But, the situation has totally changed now. Immediately after the southwest monsoon the water level in the rivers fall drastically leading to drought conditions. The wells in the river basin and the catchment areas dry up fast following the drop in underground water table, Mr Nair pointed out.

Environmental degradation is pointed out as the reason for such a dangerous situation. According to a study of the Kozhikode based Central Water Research Establishment, the water availability by 2050 in the rivers Achankovil, Pampa and Manimala would drop by 459 million cubic metres, 3,537 million cubic metres and 398 cubic metres respectively.

Sand mining coupled with the destruction of forests in the State is said to have affected the river system, he said. The soil in the forest area used to retain 40-50 per cent of the rainwater. Now, large-scale deforestation by encroachers and developmental activities has reduced the tropical forest area significantly, environmentalists pointed out.

The underground water table in the catchment areas and the river basins is related to the surface water level in the rivers. Indiscriminate sand mining during the past two decades has deepened the riverbed by an average three to four metres while there are points where it has dropped by six metres. Consequently, the water table in the wells in the catchment areas as well as in the river basins also fell sharply to the surface water levels in the rivers.

Another worrying factor is the reclamation of paddy fields and other marsh lands that used to function as natural reservoirs, where the rain water is accumulated. This also helped to maintain the underground water table at higher levels for longer periods. In such areas also now water scarcity begins immediately after the rains are over.

Another significant factor contributing negatively to the natural rainwater conservation is the removal of soil from the bushy hilly terrains for filling the low-lying areas such as paddy fields and marshlands for construction activities.

Another dangerous trend is pollution of the thin stream of water flowing down the river Pampa by dumping wastes from hospitals, hotels and even households through sewages into the river, environmental activists pointed out.

If all these activities were not controlled and regulated by the authorities the water scarcity in the State would acquire serious dimensions in the years to come, they warned.