Irrigation in India

, India

Year

2018 onwards

Duration

2000 years and ongoing

Cost

Unknown

Location

India

Project achievements

Solved the problem

Create reliable source of water for farmers all year round

Used engineering skill

Build canals and dams

Area improved

The irrigation schemes provide clean drinking water, control floods and help prevent drought

Construct irrigation schemes to grow crops and provide drinking water

India is the seventh biggest country in the world and has the second biggest population - over 1.2bn people. It’s one of the world’s fastest-growing economies.

With the bulk of its rainfall in the monsoon season - between June and October - India has had to develop irrigation systems to provide reliable sources of water all year round.

Irrigation schemes in India include networks of canals that draw water from the country’s rivers. There are also groundwater systems and projects that include rainwater harvesting.

Indian irrigation systems are mentioned in ancient texts dating back to the third century BC. The country’s oldest dam is the Kallanai Dam – also known as the Grand Anicut. The scheme was built over the Kaveri river in the south of the country around 200 AD.

The scheme is the fourth-oldest water regulation system in the world still in use. It was remodelled by British military engineers in 1804.

The 19th century saw the construction of many other British-engineered irrigation systems across the country.

Many of the schemes were used for poppy farms. The opium produced was exported to China. Around 500,000 acres in the fertile Ganges plains were devoted to the industry by 1900.

India's irrigation schemes covered about 22.6m hectares by 1951 – by then, mostly devoted to food crops.

By 2014, around 48% of agricultural land in the country was considered reliably irrigated - around two thirds of cultivated land in the country still depended on monsoon rainfall.

Irrigation in India

"Water management in India has always been an important challenge for engineers" says assistant engineer, Christopher Ackland, as he talks us through the development of India's irrigation systems over the years.

Did you know …

Although it may seem bizarre today, in the 19th century, Britain – and other countries – exported massive quantities of opium to China. British companies grew crops of poppies in India – watered by irrigation schemes built by British engineers.
Smoking opium was popular in China. By 1860, Britain was exporting about 60,000 chests a year to the country. Each chest weighed around 64kg. The trade created many thousands of addicts.
After an agreement in 1917 to ban the trade between India and China, opium smoking was finally stamped out by the Chinese communists after they came to power in 1949.

Difference the project has made

Irrigation in India helps improve crop production and increases food security – as well as reducing farmers’ dependence on monsoons.

Irrigation schemes also provide drinking water for a growing population, control floods and help prevent droughts.

Some dams used for irrigation projects are used to produce electricity.

How the work was done

The Kallanai Dam was built by King Karikalan of the Chola dynasty in the second century AD. Constructed across the River Kaveri in southern India, the engineers of the day built the massive structure using boulders of different sizes.

The second century builders shifted the stones to the Kaveri and sank them into the sandy ground across the main stream of the river. The structure they created there is 329m long, 20m wide and 5.4m high.

The scheme was intended to divert the river to fertile farmland downstream. The project successfully fed water to an area of around 69,000 acres.

The dam was remodelled by British military engineer Captain J L Caldwell in 1804. He and his team raised the dam wall by 29 inches (69cm) to increase its capacity.

Later work by the military saw undersluices – water channels controlled by gates - built across the river with outlets leading to the Kollidam river. The undersluices helped prevent the build-up of silt – making the dam more effective.

The Lower Anaicut – a dam and bridge scheme built across the Kollidam in 1902 by engineer Sir Arthur Cotton – is said to have been based on the Kallanai scheme.