Irrigation Engineering >> Surface Irrigation System

Surface irrigation system depends on simple gravity flow  of water over and across the land in order to wet it and to infiltrate into the soil. The surface irrigation system has four component: (1) water supply; (2) water conveyance or delivery; (3) water use; and (4) drainage. Most surface irrigation systems derive their water supplies from canal systems. Sometimes the water is pumped directly from groundwater.

Surface irrigation methods can be divided into furrow, borderstrip, basin or uncontrolled irrigation.

Surface irrigation system requires a number of structures which control and manage the flow and its energy. These structures should be able to do the following functions;

(1) turning the flow to a field on and off;

(2) conveying and distributing the flow among fields;

(3) water measurement, sediment and debris removal, water level stabilization;

(4) distribution of water onto the field

Careful management is required for spreading water uniformly over a field because  the soil is quite porous, and the flow rate of water is continually reduced as it spreads.

Surface irrigation is not well-suited for soils with high infiltration rates (usually the sandy and coarse-textured soils). Whereas it gives better results for soils with moderate to low infiltration rates (loams and other fine-textured soils).

Hoover dam

Surface irrigation also requires that fields should have a uniform grade in the direction of water flow to obtain best results. For unplanted field the slope should not be more than 3%.

Other irrigation methods are given below

 drip irrigation  

 sprinkler irrigation  

 sub-irrigation