Gravity Irrigation, Nebraska

Jackson Henry takes a look at the history of irrigation from Egypt and China to modern irrigation techniques such as those used in Nebraska today. This project was created through a County wide partnership with Custer County Historical Society.

(Silence through 0:23)

Jackson Henry (00:23): Gravity irrigation, or sometimes known as surface irrigation, is defined as the group of application techniques through which water is distributed over the soil surface by gravity. These systems take advantage of water's ability to travel the path of least resistance all on its own. It is by far the most common form of irrigation used throughout the world, and has been practiced in many areas virtually unchanged for thousands of years. With gravity irrigation, you can water plants anywhere.

Jackson Henry (00:58): Irrigation has been around for almost as long as people have been planting crops. Ancient civilizations in many parts of the world practiced irrigation. The earliest form of irrigation probably consisted of people carrying buckets of water from wells or rivers to pour on their crops. As better techniques developed, societies in Egypt and China built irrigation canals, dikes, dams and water storage facilities to transport and store water needed to irrigate their crops. Ancient Rome built structures called aqueducts to carry water from snow melt in the Alps to cities and towns in the valleys below. This water would then be used to drink, cook, wash things as well as people, and if course to irrigate crops.

Jackson Henry (01:51): As you can see, the process of moving water from one place to another has been used around the world for thousands of years, and has continued to be developed today. There are many different types of gravity irrigation. One type of irrigation is level-basin irrigation, which has historically been used in small areas, having level surfaces that are surrounded by earth banks. The water is applied rapidly to the entire basin, and is allowed to infiltrate the soil. In traditional basins, no water is permitted to drain from the field once it is irrigated.

Jackson Henry (02:39): Another type of surface irrigation that is used to water crops is drain-back level basin, which are a variant of basin irrigation. With this type of irrigation, the field is divided into a number of terraced rectangular bays, which are graded level or have no significant slope. Water is applied to the first bay, which is usually the highest in elevation. When the desired depth is applied, water is permitted to drain back off that bay and flow to the next bay, which is at a lower irrigation than the first. Each bay is irrigated in turn using a combination of drainage water from the previous bay and continuing inflow from the supply channel. Successful operation of these systems is reliant on the sufficient elevation drop between successive bays.

Jackson Henry (03:43): Furrow irrigation is conducted by creating channels along the field in the direction of the predominant slope. Water is applied to the top end of each furrow, and flows down the field under the influence of gravity. Water may be supplied using gated pipe, siphon and head ditch, or bankless systems. The speed of water movement is determined by many factors such as slope, surface roughness and furrow shape, but most importantly by the inflow rate and the soil infiltration rate. The crop is placed on the ridge between furrows.

Jackson Henry (04:25): Surge irrigation is a variant of furrow irrigation, where the water supply is pulsed on and off in planned time periods. The wetting and drying cycles reduce infiltration rates resulting in faster advance rates and higher uniformities than continuous flow. Border strip irrigation could be considered as a hybrid of level-basin and furrow irrigations. The field is divided into a number of bays or strips. Each bay is separated by a raised earth border. The water is applied to the top end of the bay and allowed to flow towards the bottom. Surface irrigation has been used since humans began planting crops. Its use will most likely continue as it progresses and advances, to make for better and more efficient tactics. (silence)

Asset ID: 8632
Themes: Water, waterways, agriculture, irrigation, engineering, culture, history
Date recorded: 2018
Length of recording: 5:35 m
Related traveling exhibition: Water/Ways
Sponsor or affiliated organization: Custer County Historical Society, Nebraska
More Information: https://museumonmainstreet.org/blog-node/going-distance-stories-nebraska