A watershed is the area of land from which surface runoff flows entirely through streams, rivers or lakes into the sea by a single river mouth, delta or estuary. As a management unit is considered indivisible.

When a watershed includes several autonomous state takes over management through river basin organizations, the Hydrographic Confederations.

• Classification, Structure and Functions of the Hydrographic Confederations
• Hydrographic Confederations Relations with the Autonomous Communities and Local Government
• Related legislation. River Basin Management Plans.
• More information. Document Management integrated water and watershed organizations