Merriam, John L., authorU.S. Committee on Irrigation and Drainage, publisher2020-07-142020-07-141992-10https://hdl.handle.net/10217/210768Presented at Irrigation and water resources in the 1990's: proceedings from the 1992 national conference held on October 5-7, 1992 in Phoenix, Arizona.Worldwide the on-farm water management restraints created by rigid water supply schedules cause problems of inefficient irrigation and rainfall use, high water tables, lowered production, increased and less convenient labor, complicated cultural operations, and increased costs. In the USA a beginning is just being made to modify the fixed flow rate/24 hour duration schedule to permit farmers to adjust the flow rate and duration. In developing countries frequency as well as rate and duration are usually fixed with rotation schedules. Because of the small farm sizes durations of the fixed stream vary in proportion to the farm area and not the soil intake rate nor antecedent rainfall. The rotation stream is delivered at inconvenient times and the flow rates are rigid and usually too small for practical management and for labor efficiency. High water tables correlate with inefficient irrigation. Pilot Projects designed with: adequate short-term storage to accommodate large variations in flow rate which are often greatly reduced at night; with automated canals and pipelines capable of responding to downstream farmer initiated flow variations; and with large variable streams to greatly reduce irrigation time and labor, can be used to demonstrate the value of flexible arranged or demand schedules having only economically non-restricting controls on frequency, rate, and duration.born digitalproceedings (reports)engCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Text