Hans-Julius Ahlmann is a Managing Partner of the ACO Group with its headquarters in Schleswig-Holstein. He gained a mechanical engineering degree at RWTH Aachen and completed a postgraduate course in ergonomics and economics at TU Munich. He began his professional career at the MAN group, where he stayed for three years, before leaving in 1981 to step into the footsteps of his uncle Severin Ahlmann as his successor at ACO. Under his leadership, the ACO Group grew to become the world's leading drainage technology company, an achievement realised amongst other things by strategic acquisitions such as taking over the bulk of the Passavant Werke in 2000, and starting new factories in the USA, Australia, eastern Europe, China, Arabia, Turkey and Brazil. Hans-Julius Ahlmann is married to Johanna Ahlmann, née Dräger.
Mr. and Mrs. Ahlmann are passionate sponsors of the arts. Together they created the Kunstwerk Carlshütte on the enormous site of the shut-down Carlshütte iron foundry. The heart of the Kunstwerk Carlshütte is the NordArt exhibition. NordArt is now one of the largest annual exhibitions of contemporary art in Europe: 250 selected artists from all around the world exhibit their works of art at NordArt every year. In addition, the orchestra academy of the Schleswig-Holstein Music Festival has been established in a new rehearsal venue at the Kunstwerk Carlshütte since 2011.