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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Water Management and Conservation Research » Research » Publications at this Location » Publication #182990


item Clemmens, Albert

Submitted to: Resource Magazine
Publication Type: Popular Publication
Publication Acceptance Date: 11/10/2005
Publication Date: 1/15/2006
Citation: Clemmens, A.J. 2006. Canal automation. Resource Magazine. p. 7-8

Interpretive Summary: Competition for water supplies is increasing, which prompts water districts to improve their operations. Canal automation provides potential for many water districts to improve their operations and conserve water. The paper presents an overview of canal automation issues and discusses new software developed to assist with canal automation. These results will be of use to irrigation and large water districts, the Bureau of Reclamation, and consultants.

Technical Abstract: Canals have been used to distribute water for irrigation for several millennia. The practices gradually evolved from a shovel to open gaps in a berm to fixed structures to movable structures such as gates. Regulation of water in canals is still by manual labor in most parts of the world. A few hydraulic/mechanical devices were developed to control flow rate or water level during the early part of the 20th century. Only in the last half of the 20th century have remote monitoring and automatic controls been effectively utilized. Remote monitoring with Supervisory Control and Data Acquisition (SCADA) systems have made a major impact on the operation of irrigation canal systems over the last several decades. This allows operators to control water distribution from a central location, rather than from riding or driving the canal where they could see and control only one gate structure at a time. SCADA systems are now economical for even the smallest water districts. Automatic control for individual structures to maintain a constant flow rate or to keep a local water level constant are rapidly being adopted. This is single input-single output (SISO) logic. However, effective control of canal water distribution requires the use of more sophisticated multiple input-multiple output (MIMO) logic. However, because of the long delay times for water to flow through canal sections, this MIMO control logic is complex and requires sophisticated control engineering. While this has delayed the application of more sophisticated controls, recent advancement in this application of control theory now makes the more complex MIMO controls practical. These new control methods have the potential for improving service to water users, reducing canal spills, and reducing unaccounted-for water losses. This would not be possible without some of the recent advances in electronic and computer technology.