The Hindu Business Line : Sand mining blamed for water shortage

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Kochi Feb. 2 The demand for river sand and consequent high price, following the construction boom in Kerala, has led to indiscriminate sand mining from rivers, violating the rules in several parts of the State.Deepening of the riverbed, coupled with the severe dry spell this year, has depleted groundwater level sharply.

This has resulted in the drying up of wells and ponds on which the inhabitants of river basins depend for drinking water.

If the permission is for mining 10 truckloads of sand, under its cover, at least 200 loads are taken out from the permitted area.

In the past, local people living on the embankments of the rivers used to keep vigil and stop illegal mining. But the situation has changed now, with those engaged in sand mining luring households through whose property trucks get access to the riverbed by paying Rs 50 to 200 a load, environmentalists have alleged.

FORGERY

Even forged permission letters have been used for the mining, they said. About a month back, police seized a permission letter bearing the forged signature and seal of a Tahsildar and a Panchayat Secretary.

As the sand in the Ranni region of the Pampa river in Pathanamthitta district is said to be good, aggressive mining is taking place there, they said.

The situation has reached such a stage that the groundwater level in the river basin has dropped by 3-4 metres. The riverbed has dropped by 4-6 metres.

As a result, not only have the wells and ponds dried up but saline water intrusion is also taking place in the Pampa, they said.

In the past, such a level of water shortage was felt only around March-April, whereas it had become severe now in January-February. The whole river sand bed used to act as a natural check dam because of the voids of 45 to 50 per cent in the soil where the water was retained, they told Business Line.

"This phenomenon maintains the ground water level in all the catchment areas and the river basin." When the riverbed level falls, the hydraulic gradient increases, leading to higher velocity.

As a result, immediately after the monsoon, the water that flows into the rivers is drained out quickly. Unlike in the past, rivers are filled during the rains but after a few days of dry weather, the supply is skeletal, Mr N.K. Sukumaran Nair, General Secretary of the NGO, Pampa Parirakshana Samithi, said. This led to the destruction of the riverine ecology system too, he said.

"In the absence of sand, no natural retention of water takes place. Sediment-deficient flow picks up more sediment from the stream below the mining site, furthering the degradation process," he claimed.

The monsoon season in Kerala is from June 1 to November 30. 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. Environmental degradation is pointed out as the reason for the situation.

According to a study of the Kozhikode-based Central Water Research establishment, water availability, by 2050, in the rivers Achankovil, Pampa and Manimala would drop by 459 million cubic metres, 3537 million cubic metres and 398 cubic metres, respectively.

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

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, the environmentalists warned.

More Stories on : Mining & Quarrying | Water | Environment | Kerala

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