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Montady pond, which had dried out during the middle age, was later remodelled by irrigation. This historical experience continues after more than seven centuries, according to specific knowledge and community institutions that were based on local private initiatives increasingly articulated with the public policies of the French government. Meanwhile, the radial concentric frames studied in Saïs, Morocco, can be compared with the radial concentric device of Montady. However, the technical knowledge and institutions in Morocco are the product of a specific state model of the agrarian reform. There is no evidence of any mimicry between the two examples, but they have common elements : the defence of their distinctive feature in their immediate environment and the need to maintain some cohesion around the radial concentric phenomenon.