India plans the grandest of canal networks

128 11 JULY 2014 • VOL 345 ISSUE 6193 sciencemag.org SCIENCE

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By Pallava Bagla, in New Delhi

In one of the most ambitious engineering

projects ever conceived, the Indian gov-

ernment is preparing to forge ahead on

a plan to build a 15,000-kilometer-long

network of canals and tunnels that would

move 174 billion cubic meters of water

each year—almost a third of the amount

the United States withdraws from aquifers

each year—from areas with surplus water to

parched regions of India.

The prime rationale for the $168 billion

National River Linking Project (NRLP) is

simple: To feed its growing population, the

Indian government has determined that it

must drastically expand its arable land. Now,

about 100 million hectares in India are ir-

rigated; NRLP, if fully implemented, would

increase that amount to about 135 million

hectares, while also curtailing flood damage

during the summer monsoon season and

adding another 34 gigawatts of hydropower

capacity. The current plan, honed by India’s

National Water Development Agency, envi-

sions 16 links between Himalayan-fed rivers

and rivers in drought-afflicted western India,

and another 14 links in the southern half

of the peninsula (see map). Newly elected

Indian Prime Minister Narendra Modi has

hailed the “river interlinking project” as a

national “dream.”

Thanks to Modi’s patronage, that dream

is moving closer to reality. “All possibili-

ties will be explored for early implementa-

tion of the river interlinking project,” Uma

Bharti, India’s new water minister, told

Science at a meeting here on 7 July on

cleaning up the Ganges River. But NRLP,

which could take upward of a quarter-

century to complete, faces political hur-

dles and scientific dissent. Critics contend

that the water transfer would spread

invasive species and waterborne dis-

eases and interfere with fish migration.

Water-rich states may also balk at shar-

ing. “There will undoubtedly be winners

and losers,” says Donald Alford, a hydro-

logist who has studied the Himalayas with

the firm Mountain Hydrologic Systems in

Billings, Montana. “Who, and where they

are, will help to define feasibility.”

The Indian government first proposed a

“national water grid” in 1972, but the idea,

featuring a 2640-kilometer-long canal be-

tween the Ganges and Cauvery rivers, was

shelved due to cost. Over the years, as the

project’s aspirations grew, political support

“waxed and waned,” says Upali Amarasinghe,

a statistician with the International Water

Management Institute in Hyderabad. Several

links were built, including one between the

Narmada and Sabarmati rivers in Gujarat

state, which Modi governed before becoming

prime minister.

India’s previous government, led by

Manmohan Singh, was never enamored

with NRLP and did not push for broad

implementation. “River interlinking is

against the forces of nature,” says chemist

T. Ramasami, the former secretary of the

Department of Science and Technology who

chaired a Supreme Court–mandated expert

committee on water issues. “Intense scien-

tific scrutiny,” he says, is necessary “before

such a big project is undertaken.”

NRLP critics say that Singh was right to

keep the project on ice. “The equation that

flooding means surplus water and drought

means deficit is misleading and wrong,” ar-

gues Himanshu Thakkar, an engineer with

the South Asia Network on Dams, Rivers and

People, an advocacy group based here. He

points out that areas with heavy monsoon

rainfalls can face water scarcity during the

dry season. Moreover, NRLP’s viability de-

pends on states sharing water resources—an

unreasonable assumption, Thakkar says, be-

cause “all of them are equally facing increas-

ing scarcity of water. From this point of view

alone, the links are unviable.”

That’s not how Bharti sees it. She contends

that Singh’s government “slept” on the proj-

ect, even after the Supreme Court in February

2012 held that NRLP “is a matter of national

benefit.” In a sign that the new government

will push ahead, last month it

granted permission to Gujarat

to raise the height of the Sardar

Sarovar Dam by 17 meters, tak-

ing it to 138 meters. Completed

in 2006, the hydropower project

transfers water across basins to

irrigate 1.8 million hectares; rais-

ing the height would irrigate an-

other 68,000 hectares.

Modi’s government is still

thrashing out just how fast it will

move on NRLP. Its near-term

ambitions will become apparent

when it releases its first bud-

get, for 2014 to 2015, later this

month. Whatever shape NRLP

takes, Bharti assures Science that

“no environmental laws will be

broken.” ■

Under the river-linking project, surplus

water from the Brahmaputra River would be

diverted to parched regions in northern India.

WATER

India plans the grandest of canal networksNationwide water transfer scheme could aid farming, but critics fear ecological havoc

INDIA

I N D I A

Brahmaputra

Ganges

Himalayan links

Peninsular links

Source: International Water Management Institute

Yamuna

Krishna

Cauvery

Narmada

No more going with the flowIndia’s plan calls for 15,000 kilometers of canals and tunnels (not all are shown)

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