Irrigation and Drainage Systems

According to the U.S. Department of Agriculture, drainage and irrigation systems have played major roles in the success of agricultural advancement in America. The USDA is responsible for creating innovative techniques for the efficient management of water and soil.

Identification

• Drainage is the removal of excess water from soil. Improper drainage can lead to poor soil quality and subsurface seepage could be harmful to building structures or mines.
  Irrigation is used to add water to soil to prevent over-dried ground, which can produce its own negative effects, chiefly poor soil quality and excessive dust.

System Features

• Drainage systems are either surface or subsurface, but they have similar functions. A surface drainage system has a collection ditch and a field ditch that run into a drain. A subsurface drainage system has similar components, but these are called main and sub-main conduits. Lateral conduits branch out from the water main of a subsurface drain. They both feature an outlet from which the water is then disposed.

Drainage Function

• Surface drainage takes its name from the characteristics of its function. This type of drainage is used to remove water that has built up on the surface of the ground from rain, flooding, seepage or even natural springs. Sometimes, turf-lined channels are used to divert water away from low spots. The channels lead to a more appropriate area for the water to collect. Subsurface drainage refers to the removal of water from underground soil, rather than water that has collected on the surface of the ground. Drain lines are installed under the ground along with a strategically placed porous tile, to which the water is channeled. According to Purdue University, unlike surface drainage, draining underground soil is a lengthy process.

Irrigation

• The U.S. Geological Survey states that approximately 39 percent of all freshwater in the United States is used to irrigate crops. Spray irrigation, which is similar to a lawn sprinkler, is a commonly seen method of irrigation used by American farmers. Another, slower but highly effective method used is drip irrigation, in which a pipe with small holes is placed between rows of crops and water is allowed to drip out into the surrounding ground. In the developing world, flood irrigation is still widely used. It consists of simply transporting large amounts of water through a pumping system or old fashioned bucket type containers and "flooding" the ground.

Water Conservation

• According to the Irrigation Association, irrigation systems in the United States should be managed with the continuing changes of water regulations in mind. The U.S. Environmental Protection Agency reports that accurate measurement of water depletion in soil and uniformity in irrigation are imperative to the reduction of surface water pollution. The EPA also states that landscape irrigation is a major culprit in the waste of water, using up to 1.5 billion gallons every day throughout the country, and they have teamed up with an agency called WaterSense to make education on smart water management available to the general public.