The teacher of yesteryear allowed intelligent students to express themselves: he often spent his time only giving advice. He was like the person responsible for the distribution of irrigation water in the villages: he only channelled the water to the right recipient.

For farmers like Sanit Khun, who rely heavily on the river's water for irrigation, options are drying up.

Around half of humanity relies upon water and rivers that originate in the high mountains. And, so this is used for irrigation. It is used for power production, hydroelectricity. It is used for our urban and community water supplies and it provides essential water for ecosystems from the mountaintop down to the sea.

Deforestation and poor irrigation practices can lead to irreversible desertification.

We had fire retardant, irrigation systems. We winched staff into the area to make sure that we were doing everything we could to protect the trees, and fortunately it paid off.

Central Valley produces half of all fruits and vegetables in the U.S., but requires massive irrigation, some of which requires desalination.

Algeria needs to use proper irrigation techniques.

The aquifer provides water for irrigation.

The Tuaregs use these wells for small-scale irrigation.

Rainwater is distributed through an irrigation system and collected in cisterns for the rooftop garden.