During the latter years of the Ministry there were seven District Offices (Auckland, Hamilton, Wanganui, Napier, Wellington, Christchurch and Dunedin) each headed by a District Commissioner of Works. In each District there were a number of Residency Offices (headed by a Resident Engineer) and each had a number of Depots. The primary purpose of this 6000 strong workforce was the maintenance of the existing and planning and construction of replacement sections of the State Highway network. In addition there were Project Offices set up for a particular purpose, such as to build a power project, airport, tunnel or irrigation scheme.