Thiruvananthapuram: The severe water scarcity in Chennai should sound warning bells for Kerala, says water experts. The reduction in rainfall and capacity of the soil to store water will also be a challenge for Kerala, they said.
Reducing rain
Since 1980, Kerala has been facing a reduction in rainfall. At present, from June to May, Kerala gets 2,925 mm of rain. Earlier it was 3,000 mm. That means, a 2.6% reduction in rainfall. Of the past 35 years, 25 years had rainfall lower than this. Rainfall in edavappathy (southwest monsoon), when Kerala gets its maximum rainfall, was lower than average for the past 26 years, thulavarsham (northeast monsoon) 18 years and summer rain 24 years. Due to this, Kerala had to face severe drought and drinking water shortage in 2012-13 and 2016-17.
Kerala gets 72,000 million cubic meter water through the rain a year. From this, 42,000 million cubic meters is usable. But at present we are using only 8,000 million cubic meters of rainwater, wasting 34,000 million cubic meter water every year.
Changing pattern
Kerala used to get rain for 10 months. It is no more the same. The figures for last year, when we got the maximum rains ever, too raise concerns. After the floods in August, Kerala did not experience even drizzle in September. The northeast monsoon that is usually active from October to December, ended in October itself. The summer rains from March to May recorded a deficit of 55%.
Kerala used to have an average of 110 rain days. In the recent past, it reduced to 90. In districts like Kasaragod, it dipped to 75.
Drought after floods
During the last monsoon, Kerala got 8% more rains than average rainfall. Even then, from January to May, at nearly 70% of local government bodies across Kerala, water had to be supplied in tanker lorries. By September, the rivers started drying up. Groundwater levels at coastal areas fell by one metre, inland by two-three metres and hilly regions by more than three metres.
Will Kerala become Chennai?
Tamil Nadu gets 1,500 mm of annual rainfall; about half of Kerala. Though they have double the population of Kerala, Tamil Nadu survives drought by strict water conservation. It is just the opposite in Kerala. According to a WHO study, on average a person, a day needs 135 litres of water. As per a CWRDM survey in Kerala, a person uses 400 litres of water a day; thrice the WHO figure.
'Plan now or get ready for water scarcity'
"If the government and public do not plan now, Kerala can be a Chennai soon. The water received through the rain in Kerala reaches the sea in 72 hours. Kerala, which has slanting geography, is only 35 km to 140 km wide. We do not need to look at other reasons for water that fall in rivers' catchment areas reaching the sea. Our forest cover has decreased from 50% to 27%. Paddy fields, the largest wetlands, have shrunk in the past 20 years from eight lakh hectares to 2.5 lakh hectares. Hills that store water during the rainy season has been flattened. These factors pose a big challenge for water security in Kerala. Since rivers' flow had stopped, saline water ingressed 28 km. Kerala needs to set up regulators to stop saline ingress," Dr V P Dineshan, senior principal scientist, Centre for Water Resources Development and Management, Kozhikode.
