Millennium Post

Perennial to seasonal

Majority of river basins in India are going through difficult times — declining flows, increased pollution loads and rampant habitat degradation

Our excessive interference with freshwater ecosystem has impacted every river's natural landscape, its form and flow patterns over the past three decades. The perennial rivers are becoming seasonal rivers with fragmented and intermittent flows. This is a disturbing trend, especially for plain-fed rivers of India such as Gomti, Ramganga, Chambal, Ken, Betwa and many more in the list whose only source of flow is rainfall and baseflow from groundwater. These rivers do not get any water from the Himalayan snow-melt and originate from hills, forests or lakes.

At the time of India's Independence, the per capita water availability was around 5,200 cubic metres (cum), which has now dropped to 1,500 cum. With the rapid growth in population, urbanisation and industrialisation, rivers have been increasingly controlled by dams, diverted and over-allocated for agricultural, domestic and industrial purposes. In doing so, we resorted to various 'quick-fix' solutions such as excessive groundwater abstraction, led by the pump-revolution starting late 1970s that led to the drying of many rivers during lean seasons.

A river must have sufficient flow to match downstream allocations to meet societal needs as well as to maintain its aquatic life forms. Rivers in the urban stretch are expected to carry most of the brunt costs for infrastructure and metropolitan growth and development. Floodplains and river corridors are struggling with a spatial mismatch with real estate projects siphoning the life out of historic ghats and ecologically rich river banks while turning the river terrace into a built landscape. Though urban rivers are still termed as 'rivers of life', they have been victims of built legacy, often treated without ecological and cultural enrichment.

River corridors and active floodplains are rapidly transforming into agricultural lands and urban settlements. It is a bitter fact that along with Ganga, the flow in most of its tributaries has dropped. The flow in the Ramganga river has alone dropped by 65 per cent between 2000 to 2018 at major stretches.

Similarly, the Gomti shows a declining trend due to over-exploitation of groundwater in its catchments. Its flow has declined by almost 52 per cent between 1978 to 2016. The Krishna is the fourth-biggest river of India in terms of water inflows and river basin area, but its flow is getting thinner with each passing year. Its delta will turn into a desert due to over-allocation from several major and medium irrigation projects. The situation is so awful that borewells and open wells too have started drying in many villages of Belagavi district.

Similarly, Cauvery river is under severe stress and dried up at several places the last many summers. From its origin in Talakaveri, the 765-km-long river flows through Hassan, Mandya and Mysuru districts in Karnataka before entering Tamil Nadu — the lower riparian state where many of its tributaries face a slow demise.

The Godavari, earlier a perennial water source for Telangana, now struggles for survival. Locals say this is the worst they have seen the river look in the last 45 years.

Most of the major river basins in India are going through difficult times — declining flows, increased pollution loads and rampant habitat degradation. But the policy response from both the Centre and states have been poor. Various schemes and policy strategies hardly evoked any major restoration plan on the ground. Even India's water policy fails miserably to formulate a solid plan to restore many of its degraded river systems.

The focus has mainly been on building dams and canals using limited river water. The management of rivers by default has gone to the irrigation department whose engineers do not talk about restoration of flows and conservation of river ecosystems. They do not understand the difference in the valuation of water infrastructure and having water in the river with healthy ecosystem functions. Maintenance of water infrastructure is given topmost priority while ignoring the very source of natural water resources, the catchments and many natural channels that feed them.

The major rivers of India depend upon many of their smaller tributaries and natural channels. No one is talking to restore these smaller rivers. Our largest share of freshwater, almost 85 per cent, goes to irrigate our farms.

With the development in drilling and pump-technology, we are going deeper and deeper into the aquifers leading to massive groundwater abstraction. This has resulted in the lowering of the water table to levels below that of the river and forcing the river to feed the groundwater instead. This has robbed water from our plain-fed rivers as they depend largely upon groundwater during summer. India's once-perennial rivers are dying, and we need to work on their restoration plan and all aspects which affect river flows through robust institutions and governance at the river basin level. DOWN TO EARTH

(The author is a river scientist and associate professor at the School for Environmental Sciences, Ambedkar University, Lucknow. He is also a Gomti River Waterkeeper. The views expressed are strictly personal)

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