 Geo-political definitions of the valley depend on the defining authority.The Po Basin Water Board (""), authorized in 1989 by Law no.183/89 to oversee "protection of lands, water rehabilitation, the use and management of hydro resources for the national economic and social development, and protection of related environment" within the Po basin, has authority in several administrative regions of north Italy, including the plain north of the Adriatic and the territory south of the lower Po, as shown in the regional depiction included with this article.