For a decade, conflicts are produced between political parties, and also in the civil society, by problems related with the management of water resources. Frequently, the thematic of these debates is the ecological problems related with the future of the Ebro delta. Nevertheless, the radical and perhaps most important cause of this confliction is in the legal and institutional chaos that exists in the management of underground waters in almost all Spain and of singular way in the river basin of the Segura. In this brief article the importance of this cause is put of relief, generally ignored so much by the politicians as by most of the ecological groups.