a. The primary plot
The primary plot consists of several secondary plot, which take water directly from the primary channel. The primary plot served by the primary channels that take water directly from the water source, usually a river. Certain irrigation projects have two primary channels. It produces two primary plot. The area along the primary channels often can not be serviced easily by tapping the water from the secondary channel. If the primary channel passes along the high line, the primary channel adjacent area to be served directly from the primary channel.
b. Tertiary plot
Basic plan concerning irrigation unit is tertiary. Tertiary receive irrigation water applied and measured at the tap building tertiary. Tertiary tap building tertiary canals to drain water. At the tertiary water distribution, exploitation and maintenance are the responsibility of the farmers concerned, under the guidance of the government. Tertiary that is too large will cause the water division becomes inefficient.
Other important factors are the number of farmers in one plot, species of plants and topography. In areas planted to rice extensive tertiary ideally a maximum of 50 ha, but in certain circumstances can be tolerated up to an area of 75 ha, adapted to the topography and the ease of exploitation in order to make the implementation of the operation and maintenance easier. Tertiary must have clear boundaries such as trenches, roads, village boundaries and limits deformation field.
Tertiary divided into plots quarter, each of approximately 8-15 ha. If the topography allows, preferably tertiary form a square or rectangle to simplify the layout and enables the sharing of water efficiently. Tertiary must be located directly adjacent to the primary channel or secondary channel.
An exception if the plots tertiary not directly located along the main irrigation channel network that is as such, require tertiary channels that restrict other tertiary plots, this should be avoided. Tertiary channel length should be less than 1,500 m, but in fact sometimes the channel length is 2,500 m. Quarter better channel length below 500 m, but in practice sometimes up to 800 m.
c. Secondary plot
Secondary plot consists of several tertiary, all of which are served by a secondary channel. Usually receive water from the secondary plot for the building located at the primary or secondary channel.
The boundaries of the secondary plot is generally a sign of a clear topography, such as the discharge channel. Extensive secondary plots can vary, depending on the local situation.
Secondary channels are often located at the back of the field irrigate both sides of the channel to discharge channel that limit. Secondary channels may also direncana as high line canal that irrigates the slopes of the lower field alone.