Based on the definition and definition of irrigation as stated above, irrigation activities can be divided into 2 (two) main principles, namely: 1) the principle of addition and 2) the principle of supply. For wet tropical regions such as Indonesia, irrigation activities adhere to the principle: the addition of water into the ground to increase or meet the water needs of plants that cannot be supplied by rainwater supplies or other water supplies.
In the rainy season, when the supply of rain water is sufficient to meet the needs of water plants, the addition of irrigation water is not necessary. Whereas for dry climates, the principle of water supply or supply is to provide water for plant roots that are not available or not available at all because there is no rain or other water supplies. In areas with dry climates, rain rarely occurs so that the supply of rainwater in the root zone of plants is limited or even does not exist at all to meet the needs of plants, so it must be provided through irrigation. These two principles have different technological consequences and water management.
How to provide water into the root zone of the plant can be done by splashing from the top of the plant surface (overhead irrigation), can be by way of inundation on the whole land (basin irrigation) or inundation in certain parts by making ditches or canals (furrow irrigation). Irrigation water can also be provided through the subsurface, using subsurface open channels or perforated water pipes installed below the surface.
1) Activities related to taking water from its source, transporting water and sharing and providing irrigation water to the land in need. These three sub-activities are closely related to physical and technological facilities and infrastructure used,
2) Activities related to the management of operations and maintenance of selected irrigation facilities. This sub-activity is closely related to software systems,
3) Activities related to organizations and institutions for irrigation operations and management. This sub-activity is related to the regulation, regulations and laws of irrigation and water resources.
Irrigation functional performance is generally assessed from the efficiency and effectiveness of taking, transporting and providing irrigation water, or productivity of irrigation water which is highly determined by the performance of the three aspects of activities.