[EN] Traditional irrigation systems preserve important natural and cultural values, which deserve protection and reconnaissance. In order to develop this heritage assessment the focus should be placed on the concept of Agrarian Heritage, because despite the important hydraulic values of these systems, irrigation is a mere instrument for agrarian production and human settlements. This paper, based on the Project PAGO (Agrarian Heritage: cultural landscape construction through agrarian activity, HAR2010- 15809), stablishes which are the values that should be considered in the historical irrigation systems, and mainly, the mechanisms and criteria for delimitation and protection, focusing in the study case of the Vega the Granada hydraulic system.