Irrigated Agriculture Technologies, Practices, and Implications for Water Scarcity

U.S. Government Accountability Office (GAO) | November 12th, 2019

Demand for freshwater surpasses the amount naturally available in some areas of the United States. The agriculture sector competes for this limited resource, and withdraw

Demand for freshwater surpasses the amount naturally available in some areas of the United States. The agriculture sector competes for this limited resource, and withdraws and consumes the most freshwater of any user in the nation. GAO was asked to conduct a technology assessment around agricultural water use. This report provides an overview of irrigation technologies and on-farm water conservation practices, factors influencing the adoption of these technologies, and implications of their use for water scarcity. In conducting this assessment, GAO reviewed scientific literature; convened an expert meeting with the assistance of the National Academies; visited farmers, academics, and industry representatives; interviewed officials from federal agencies; modeled water use in an illustrative watershed; and performed a regression analysis on U.S. Department of Agriculture irrigation, crop, and technology data. GAO describes two policy options that federal policymakers could consider relating to irrigation technology and discusses their benefits and challenges.

Irrigating Machinery on the Pacific Coast

Scientific American | December 17th, 1887

In offering the present paper to the Institution of Mechanical Engineers, the author does so with a tolerably complete knowledge of the very advanced practice in England

In offering the present paper to the Institution of Mechanical Engineers, the author does so with a tolerably complete knowledge of the very advanced practice in England in this class of machinery: and his purpose is mainly to explain the differences that have been called for by local circumstances in California. Character of the Country: The western or Pacific slope of the Sierra Nevada or coast range of mountains in California is very abrupt, the crests of the range being so near that the snow is visible from the coast during the whole year. Hundreds of streams cross this narrow country, falling either direct into the Pacific Ocean or into the great basin formed by the Sacramento and San Joaquin rivers. These two rivers. the largest in California, run in opposite directions nearly parallel with the coast and meet at the Bay of San Francisco forming ac ontinuous valley 400 miles long and from 50 to 100 miles wide. The small streams for the most part are fed by melting snow in the summer; and every gulch or canon has its rivulet or brook. They increase in volume until they pass into or through the hills at the foot of the mountain range; and there, unless of considerable size, they may wholly disappear in summer by percolation through the silt or by evaporation. Streams exposed to the torrid air which in summer sweeps across the sand deserts of Southern California are dried up with wonderful rapidity. The evaporation from Salt Lake, exposed to the same dry wind, is sometimes equal to half an inch per day. or 64 million tons of water. Not withstanding this great loss by evaporation, the quantity of water falling into the ocean on the coast of California has been estimated at 100 million cubic feet or 2 3/4 million tons per minute, enough, if distributed properly, to irrigate 25,000 square miles.

Irrigation

Scientific American | January 10th, 1903

Irrigation has been practised in America from time immemorial by the town-building Pueblo Indian tribes inhabiting portions of New Mexico and Arizona. Their ancie

Irrigation has been practised in America from time immemorial by the town-building Pueblo Indian tribes inhabiting portions of New Mexico and Arizona. Their ancient canals may still be traced across the broad valleys. through which are scattered the almost innu merable ruins of community dwellings. On the mesas of southwestern Colorado and adjacent portions of Utah, Arizona, and New Mexico are found the wonderful cliff dwellings, and in the little valleys near these may be seen ditches which were in use perhaps a thousand or more years ago.

Irrigation

Scientific American | January 17th, 1903

Irrigation in California

Scientific American | January 4th, 1890

Irrigation in California

Scientific American | January 5th, 1884

Irrigation in Southern California

Scientific American | December 17th, 1904

As an example of the beneficent results of irrigation of desert lands, a project which has been undertaken in Southern California is probably one of the most notable i

As an example of the beneficent results of irrigation of desert lands, a project which has been undertaken in Southern California is probably one of the most notable in America, for its promoters selected a region most of which was entirely devoid of vegetation in any form, the soil, if it can be called such, not even containing enough elements of fertility to nourish the sparse vegetation found in the so-called desert of the Southwest. Prior to the reclamation of this land, one could travel for miles without seeing any vegetation. Most of the area referred to forms a part of the Colorado Valley, and is situated in San Diego County. The head of the canal was located on the river at a point seven miles west of Yuma, Arizona, and but a short distance from the boundary between California and Mexico. Here the elevation is 120 feet above sea level, a sufficient altitude to give an average fall of from four to six feet to the mile. It was found impossible to construct the waterway in a straight line, owing to the topography of the country, and in its course it makes a wide detour, passing through a portion of the Mexican republic. It is unique from the fact that it is probably the only international irrigation canal in the world, the water being used to cultivate a considerable area in the southern republic.

Irrigation in the Earth system

Nature Portfolio (Springer Nature) | June 20th, 2023

Irrigation in U.S. Agriculture: On-Farm Technologies and Best Management Practices

Congressional Research Service (CRS) | October 17th, 2016

Recent threats to water availability as a result of moderate to exceptional drought in several states have raised questions about agricultural water use and efficiencies

Recent threats to water availability as a result of moderate to exceptional drought in several states have raised questions about agricultural water use and efficiencies across the United States. An understanding of common irrigation technologies and the impacts of best management practices in irrigation may be useful to Congress concerning potential policy responses to this issue. As a major user of water, the agricultural industry’s use of water resources continues to be a focal point of agriculture policy. Additional demands on water supplies, extreme weather events (e.g., prolonged drought), and agricultural market conditions have raised producers’ interest in investing in irrigation systems. Increased pressure on the industry to reduce its water use has also drawn interest in the adoption of irrigation technologies and best management practices (BMPs) as a means of achieving efficiency and potential water savings. The federal government performs several roles in assisting agricultural producers with irrigation practices, including financial assistance, technical assistance, research, and monitoring and reporting. The majority of financial and technical assistance is offered through voluntary conservation programs that target increased irrigation efficiency. In some cases, improvements in irrigation efficiency can increase water consumption because farmers increase the number of irrigated acres or grow more profitable, water-intensive crops. This raises questions about how and where federal funds are allocated, particularly in areas where water shortages are a concern. The use and significance of irrigated agriculture varies widely across the United States. Although policy discussions related to irrigation typically focus on western states—home to roughly 71% of irrigated farms—irrigation is practiced in all 50 states and is growing in the east. Over time, there has been a shift in water resources used for irrigation, with an increasing reliance on groundwater and less on the use of surface water. The type of irrigation system used has also shifted over time—from a gravity, or flood-type of irrigation, to potentially more efficient pressurized sprinkler and drip irrigation systems. Pressure systems account for between 58 to 65% of irrigation systems used in the United States and include applicators such as center pivot, surface drip, slide roll or wheel move, and micro sprinkler. Gravity flow, which includes furrow, and controlled and uncontrolled flooding, accounts for approximately 35 to 42% of irrigation systems in the United States. Irrigation BMPs center around how water is managed on a farm and includes on-farm conveyance, irrigation scheduling, and application methods. Increasingly, precision technologies (e.g., drones, sensor networks, data analytics, etc.) are becoming a common part of many irrigation systems because of their potential to increase efficiencies and reduce costs. The use of irrigation technology and BMPs bring both benefits and costs. The control of water application achieved through irrigation systems can create higher yields and allow the production of higher value crops, while potentially reducing some production costs. The additional cost of installing and maintaining these systems, however, can present a barrier to implementing BMPs. Accounting for variations in the local climate, soil type, water quality, and water availability may also challenge adoption of irrigation technologies and BMPs.

Irrigation of Twelve Million Acres in the Valley of California

U.S. Geological Survey (USGS) | November 15th, 1920