Flood irrigation has been around for thousands of years. The Egyptians used to use it for irrigating crops. It is one of the simplest methods of watering a large garden or area. Very little expense is needed in using a flood irrigation system.
Ancient Egypt used this method to water crops and plants along the banks of the Nile river. The water was transferred to the farmland through water channels called furrows where the plants were located. California's agriculture also used a system of flood irrigation to water plants and it still does in some areas today.
How it works
Flood irrigation for a garden is simply flooding the whole garden with water at one time. There are two methods that can be used to do this. The first way is to hill dirt up around the outside edges of the entire garden that you want watered. The hill surrounding the garden needs to be 5 to 6 inches high. The second method takes a little more time and effort to do because it requires more labor. The area that is planned for the garden must be dug out at least 5 to 6 inches deep. This allows a sunken area that is below ground level for plants to be planted in. Then, you turn on your hose or water source and allow the water to fill the entire area. Once the area is filled, turn off the water and allow it to drain into the soil. If the water has not drained within a few hours, then open a small section in the hill and let the water run off. This will keep the plants from getting too much water that will damage the plants.
There are several benefits of this type of watering system. It allows an individual to water a large area all at one time, making it easier and less time-consuming. This also helps to lessen the expense of having to purchase extra hoses and pipes. Another reason to flood irrigate is if you are using hoses to run water from a nearby river or stream, the hoses and pipes would fill with the sediment from the water and plug them up. It also helps to water plants that have deep root systems such as trees and shrubs in your yard and garden, because some clay soils take longer to penetrate through.
There are a few disadvantages to using this type of watering method. In very hot, dry areas, water evaporation is high and a lot of the water that is in the garden will simply evaporate out. Water runoff is another problem with this method of watering because there is always water that leaks out from the garden through breaks in the dirt walls. Also, there is usually water that has to be drained off the garden if it doesn't soak in, adding another step to the process.