Why water scarcity is more in rain dependent Southern states than the north?

Bengaluru: In the Indian peninsula across the five southern states of Andhra Pradesh, Karnataka, Kerala, Tamil Nadu and Telangana, water is a precious resource due to shortage, especially in densely-populated cities, as its sources are depleting owing to over-exploitation, vanishing lakes and ponds and encroachments preventing their conservation.

Unlike in the Indo-Gangetic plains across the northern and eastern states, where mighty rivers like the Ganga and the Brahmaputra flow perennially, thanks to the melting ice of the Himalayas, rivers and waterbodies across the southern states are rain-dependent during the southwest and northeast monsoons from June to December.

As the main source of water, major intra-state and inter-state rivers like the Cauvery, Godavari, Krishna, Palar, Pampa, Pennar, Periyar, Tungabhadra and Vaigai and their tributaries are rain dependent and their flow depends on how active the twin monsoons are through the second half of a year.

With the Cauvery flowing into Tamil Nadu and Kerala from Karnataka and the Krishna passing through Karnataka from Maharashtra to Telangana and Andhra Pradesh, sharing the natural resource has been a bone of contention among them over decades, resulting in protracted political and legal battles for fair distribution.

Lack of consensus and reciprocity over sharing the river waters in times of distress led to disputes on the Cauvery among Karnataka, Tamil Nadu and Kerala; on the Krishna among Maharashtra, Karnataka and Telangana/Andhra Pradesh and on raising water storage level in the Mullaperiyar dam between Tamil Nadu and Kerala.

The disputes led the affected states to seek the central government's intervention and the setting up of tribunals and directives from the Supreme Court to resolve them.

Karnataka is also in dispute with neigbouring Goa over sharing of the Mahadayi river's water to meet the drinking water needs of people in the state's northern region.

Though Tamil Nadu succeeded in getting its share of Cauvery water from the inter-state tribunal, as notified by the central government in the final order on February 19, 2013, some issues remain to be sorted out.

The 800 km-long Cauvery, which originates at Talakaveri near Kodagu in the Western Ghats, flows southwards to Tamil Nadu, Puducherry and Kerala and empties into the Bay of Bengal in the east.

Despite pressure from Tamil Nadu Chief Minister J. Jayalaithaa, the central government is yet to set up the Cauvery Management Board and the Cauvery Water Regulation Committee to implement the tribunal's award.

Earlier, Karnataka challenged the February 5, 2007, award of the Cauvery tribunal in the Supreme Court through a special leave petition. Tamil Nadu and Kerala also challenged the central government's 2013 order. The final hearing is on July 19.

Tamil Nadu has also opposed Karnataka's Mekedatu reservoir project across the river near Kanakapura, about 100 km from Bengaluru, ostensibly to generate hydel power and supply drinking water to the parched Chikkaballapur and Kolar districts.

Karnataka Chief Minister Siddaramaiah clarified that the dam was within the framework of the tribunal order and claimed that it was not for irrigation.

Similarly, Tamil Nadu and Kerala have been at loggerheads over the Mullaperiyar dam since 2014, when its water storage level touched 142 feet after three decades following copious rains in its catchment area, which lies in Kerala.

Though the dam across the Periyar, built under an 1886 accord by the then maharaja of Travancore and the British Raj, is located at Thekkady in Idukki district of Kerala, it is owned, maintained and operated by Tamil Nadu.

The Supreme Court, on May 5, 2014, decreed in favour of Tamil Nadu and permitted the state to raise the dam's water level to 142 feet from 136 feet.

Kerala, however, wants to build a new dam so that it will be under its control.

Likewise, the dispute over sharing of Krishna water fairly during distress years made the central government set up a tribunal in 1969 under the Inter-state Water Disputes Act.

As the peninsula's second biggest river, the 1,300-km-long Krishna originates near Mahabaleshwar in Maharashtra, snakes through north Karnataka and flows into Telangana and Andhra Pradesh before emptying into the Bay of Bengal.

Headed by former Supreme Court judge R.S. Bachawat, the Krishna Water Disputes Tribunal awarded 560 thousand million cubic (tmc) feet to Maharashtra, 700 tmc to Karnataka and 800 tmc to then undivided Andhra Pradesh in 1973.

When the award was notified on May 31, 1976, disagreements over the allotment forced the setting up of the second tribunal in 2004, which on December 31, 2010, re-allocated the resource - giving 1,001 tmc to Andhra, 911 tmc to Karnataka and 666 tmc to Maharashtra.

According to G.S. Srinivasa Reddy, director of the Karnataka State Natural Disaster Monitoring Centre, the failure of the monsoon in 2015 has led to severe water shortages across the state, with levels in rivers and reservoirs plunging to their lowest.

As the second largest arid state after Rajasthan, water shortage is acute in the dry and backward regions of northern Karnataka in the Deccan plateau. With lakes, ponds, tanks and water bodies drying up, borewells are being drilled up to 800-1,000 feet to supply drinking water to villages and towns in districts across the state.

The crisis among the southern states is also compounded by increasing demand due to steady migration of people to towns and cities where supply constraints force civic agencies to ration water.

Sharp falls in water levels in dams, drying up of reservoirs and the fast-depleting ground water table have led to acute drinking water problem in Telangana and Andhra due to the second consecutive drought year.

Farmers and their labour are the worst hit by the water crisis gripping the twin states. With no water to quench the thirst of cattle, their owners are forced to sell them in distress across the two states.

Unchecked urban growth and poor planning is forcing 50 percent of the denizens in cities to depend on borewells and tanker suppliers. The situation is grim in tier-two and tier-three cities, where daily water supply is a luxury.

According to a study by the Kerala Agricultural University (KAU), the state will face severe water scarcity by 2021, with a projected demand-supply gap of 1,268 billion litres.

Kerala State Biodiversity Board member-secretary K.P. Laladhas observed that the coastal state was going to face acute water shortage in future.

"As one of the wettest regions in the country, Kerala is lagging behind in per capita availability of drinking water. Many lakes and rivers, source of drinking and irrigation, have reduced to thin streams," Laladhas told IANS.