At low water the wharf was inaccessible from the river due to the shallow water at this point. Repeated requests were necessary before the problems were rectified. An outbreak of scarlet fever in 1889 lent urgency to the already noted need for isolation wards in which to treat sick immigrants. The same year a facility was constructed, but, due to an oversight in the plans, it had no facilities for the provision of gas or water or for the disposal of waste and storm water. Similar problems dogged the long-awaited "disinfecting plant" which was first vandalised and later inundated due to faulty drainage. When immigration levels were low, the building was used for a variety of purposes. In 1900 it served as temporary accommodation for the inmates of the Dunwich Asylum which had been appropriated as an isolation ward for plague victims. In 1904-1906 it was again appropriated as accommodation for South Sea Islanders being repatriated under the new Commonwealth laws. The arrival of an immigrant ship led to the re-location of the Islanders to rented accommodation nearby as it was considered inappropriate to expect the "two races" to co-habit. The outbreak of World War I led to another change in use, the building being requisitioned for use as a military hospital. Few alterations to the fabric occurred as a consequence, although two single-storey wards were constructed to the southeast of the building. At the end of the war, the building provided an ideal reception area for returning servicemen who, with their wives, were feted at public receptions. Most of the building activity associated with this phase was removed at the end of the war. From the end of World War I and throughout the 1920s, immigration swelled. The Great Depression of the 1930s led to a rapid fall in numbers, exacerbated by the cancellation of the assisted passage schemes. In 1938 the assistance scheme was reinstated and numbers rapidly climbed, only to fall again with the commencement of World War II. During the period of inactivity in the 1930s, the building was used to house the team working on the construction of the Story Bridge. Accommodation for the superintendent of works, John Bradfield, was provided in the eastern room on the ground floor of the north wing. The entire upper floor of the north wing was devoted to offices and drafting rooms for the works in progress. Four dormer windows were inserted into the roof of the North wing dormitory to provide additional light for the draftsmen. The team for the concurrent Stanley River Dam project were relegated to a large room on the lower floor  The bridge construction was undertaken by Evans Deakin, who converted the immigration depot's grounds into an industrial site with workshops and storehouses.