Abstarct: This paper is a computational programming model for optimal design of water networks in agriculture. The proposed model is baxsed on a new structure that includes all the settings for the use, reuse and regeneration of water in a field that is formed by a number of croplands. This model also includes the allocation of pipelines, pumps and storage tanks in different irrigation periods. Targeted performance includes maximizing the annual profits, which is comprised of economic incomes from crop sell, minus the costs of fresh water, fertilizer, storage tanks, treatment units, piping and pumping. The proposed multi-period optimization problem is designed as a mixed integer non-linear programming formulation that was used to case studies to illustrate the economic, environmental and social benefits that can be gained.