Why is the Cauvery drying?

In April 2024, two shocking news reports revealed that the upper reach of the Cauvery River at Dubare in Kodagu and its tributary, Hemavathi near Sakleshpur in Karnataka, had dried up. This unprecedented event has caused widespread concern, as the perennial rivers from the Western Ghats are the lifelines for farming and drinking water in both urban and rural areas. 

Karnataka suffered a severe water crisis due to the failure of both the Southwest (SW) monsoon and the Northeast (NE) monsoons in 2023, leading to drought conditions that severely affected farming and water supply in Bengaluru and surrounding areas. While drought is not new to Karnataka, having occurred in the 1960s, 1970s, 2000s, and 2010s, the drying up of perennial rivers at their source in the Western Ghats is
unprecedented, raising alarm among people and the government.

Several factors contributed to the drying of the Cauvery River, including global warming and El-Nino, which affect the SW monsoon rains in India. The Western Ghats, which are the source of many South Indian rivers, including the Cauvery, Sharavati, and Tungabhadra, are particularly vulnerable.

El-Nino, characterised by warm air from the central and eastern Pacific Ocean, disrupts SW monsoons, while La-Nina, characterised by cool air from the same region, tends to ensure better SW monsoon rains in India and droughts elsewhere in the world.

The Western Ghats are the home of evergreen and deciduous forests that play a crucial ecological role by attracting SW monsoon clouds, facilitating precipitation, preventing soil erosion, and enabling rainwater infiltration to replenish groundwater. This groundwater then feeds streams and rivers year-round, maintaining their perennial flow.

However, the forests of the Western Ghats have been plundered for multipurpose dams, power projects, roads, housing, and agriculture in the past. Tree felling and an ineffective Forest Act have further degraded and shrunk the forests. Since the 1990s, invasive weeds such as Lantana and Parthenium have further disrupted forest ecosystems, affecting natural regeneration.

This environmental degradation, coupled with global warming and decreasing rainfall, has led to the drying up of subsoil water and the cessation of water flow in the upper reaches of the Cauvery and Tungabhadra during the summer of 2024.

The remedies to tackle the catastrophic drying up of the Cauvery and other perennial rivers in the Western Ghats require committed effort from stakeholders and governments.

For the Cauvery basin, this involves the collaboration of the stakeholders, i.e., the people residing in the command area of Cauvery and the cities that use its water for farming and drinking in Karnataka, Tamil Nadu, and Pondicherry. They must discuss the causes of the drying up of the upper basin of the Cauvery, identify problems, plan mitigation measures, secure funding, and implement projects to rejuvenate the forests in the upper regions of the Cauvery basin. This effort should involve local communities in the Ghats through an area development project.

Unfortunately, the responsibility of addressing forest depletion and river drying in the Western Ghats seems to have been largely left to the Karnataka Forest Department (KFD), which lacks the resources to tackle such issues without special projects akin to the ‘River Valley Projects’ under India’s Five Year Plans.

As the 2024 general election for the 18th Lok Sabha progresses, none of the major political parties have prioritised or even shown concern for global warming, climate change, droughts, or cloud bursts or for mitigating measures in the manifestos. The conservation and rejuvenation of the forests, ecology, and ecosystems in the river basins to address climate issues do not find a mention in the manifestos.

Long-term projects are needed to consolidate forests, halt encroachments, establish forest boundaries, improve forest density to suppress invasive weeds, regenerate degraded forests, and enhance marshlands to improve subsoil seepage into the rivers. Such efforts will enable the Western Ghats to continue performing their essential ecological functions. All the concerned states that depend on the Cauvery River and the Government of India have to fund the project as long as water is required for the public, cattle, and wildlife.

(The writer is a retired Indian Forest Service Officer and an author based in Bengaluru)