Baseline data for improvement of a distributary canal system

Using an interdisciplinary approach, the program included the design, construction, and operation of a system to deliver water to all farms in sufficient quantity at appropriate times to meet all water needs; to deliver water at an adequate and equitable flow rate and head; and to minimize surface losses to drains. The original system was designed, built, and operated under certain physical and operational assumptions that would minimize water use while maximizing crop yields for all individual users. This technical report describes the physical characteristics of the existing system, including water supply, canal structures, canal and mesqa surveys, soil conditions, crop patterns, water table levels, on-farm irrigation, and water delivery requirements. The socioeconomic characteristics of the existing system are also evaluated to assist in developing an equitable water user management program. The Daqalt Canal does not meet its original objectives due to water shortages, inadequate and inequitable flow rates and heads, and large surface losses to drains. These problems are caused by ineffective physical structures operation, conflicts with irrigation timing preferences, and poor canal maintenance. As a result, the system falls short of desired performance due to incorrect assumptions and improper management. The entire water delivery system requires renovation within the context of the larger irrigation system. The report recommends that a complete hydraulic model of the existing Daqalt system be developed in accordance with available water levels in the Mit Yazid Canal, and that the design be re-evaluated in light of this model. The renovation process should continue, and water users should participate in the design and operation of the water management plan. (Author abstract)