What are the Sources of Water for Irrigation?

Water for Irrigation

What are the Sources of Water for Irrigation?

Surface water (taken from rivers, lakes, or reservoirs), groundwater (extracted from springs or wells), or unconventional sources (such as treated sewage, desalinated water, drainage water, or fog collecting) can all be used for irrigation.

Spate irrigation, also known as floodwater harvesting, is a unique type of irrigation that uses surface water. Using a system of dams, gates, and channels, water is diverted to normally dry riverbanks (wadis) in the event of a flood (spate) and distributed across a vast region. Crops will thereafter be grown using the soil's stored moisture. Spate irrigation areas are mostly found in semi-arid or desert highland environments. While floodwater gathering is one of the approved irrigation technologies, rainwater harvesting is not commonly considered irrigation. Rainwater harvesting is the gathering and concentration of runoff water from roofs or vacant land.

Around 90% of global wastewater production goes untreated, creating widespread water pollution, particularly in low-income countries. Untreated wastewater is increasingly being used as a source of irrigation water in agriculture. Cities are appealing to farmers because they provide lucrative marketplaces for fresh food. However, because agriculture must compete for increasingly precious water supplies with industry and municipal users, farmers are frequently forced to use dirty water, including sewage, to water their crops. Significant health risks can result from using pathogen-infested water in this manner, especially if people consume raw vegetables that have been watered with the polluted water.