Sources of Irrigation Water

Sources of irrigation water can be groundwater extracted from springs or by using wells, surface water withdrawn from rivers, lakes or reservoirs or non-conventional sources like treated wastewater, desalinated water or drainage water. A special form of irrigation using surface water is spate irrigation, also called floodwater harvesting. In case of a flood (spate) water is diverted to normally dry river beds using a network of dams, gates and channels and spread over large areas.

The moisture stored in the soil will be used thereafter to grow crops. Spate irrigation areas are in particular located in semi-arid or arid, mountainous regions. While floodwater harvesting belongs to the accepted irrigation methods, rainwater harvesting is usually not considered as a form of irrigation.

Rainwater harvesting is the collection of runoff water from roofs or unused land and the concentration of this water on cultivated land. Therefore this method is considered as a water concentration method.

Problems in Irrigation

Competition for surface water rights.
Depletion of underground aquifers.
Ground subsidence (e.g. New Orleans, Louisiana)
Buildup of toxic salts on soil surface in areas of high evaporation. This requires either leaching to remove these salts and a method of drainage to carry the salts away or use of mulch to minimize evaporation.

Over irrigation because of poor distribution uniformity or management wastes water, chemicals, and may lead to water pollution.

Related Artilces

Gardening Services

More Information

Sources of Irrigation Water

Problems in Irrigation