This contribution was submitted by Dr Katrina Proust, Centre for Resource and Environmental Studies, The Australian National University.

McKinney graduated in engineering from the Queen's College Belfast, and was articled to Samuel Roberts, Chief Engineer for Waterworks, Galway. In 1867 he received a Diploma of Civil Engineering with honours and, in the next year, he obtained third place in open competition for appointments in the Indian Public Works Department. In 1869 he sailed to Calcutta to join the Bengal Public Works Department. First, he was stationed at Amritsar in Punjab. As Assistant Engineer (3rd grade) he was assigned to various engineering works on the Bari Doab Canal which would provide irrigation to land between the Beas and Ravi Rivers. In 1876 McKinney transferred to the Irrigation Department of the North-Western Provinces and was stationed at Saharunpur. In this district he worked on irrigation development for land served by the Eastern Jumna Canal and the Ganges Canal. In 1878-1879, as Assistant Engineer, he worked on drainage projects in areas of the Lower Ganges Canal that were seriously affected by irrigation salinity. After qualifying in canal law he also exercised the duties of Canal Magistrate.

While on leave from India in 1876 McKinney visited New South Wales, where he toured the Riverina with relatives who held large pastoral interests at Kooba and Pomingalarna stations. Later, after completing his ten-year tour of duty in India, McKinney moved permanently to Sydney. In 1880 he joined the Harbours and Rivers Branch of the NSW Public Works Department. He was employed on the Upper Nepean Scheme for the Sydney water supply, first as Resident Engineer, then as District Engineer.

In 1884, prompted by interest in developing the colony's water resources, the NSW Government convened the first public inquiry into water conservation, known as the Lyne Royal Commission (1884-1887), and appointed McKinney engineer assisting the Commission. During this period McKinney completed surveys of the Murray and Darling rivers, and instituted a system of river gauging of discharges on all major rivers in the colony. When the work of the Commission was formally completed, he was appointed to run the newly created Water Conservation, Irrigation and Drainage Branch of the NSW Public Works Department. With a small staff from the Lyne Royal Commission he continued to gather hydrological data on NSW rivers.

In 1890 McKinney was appointed Commissioner-in-Charge of the Murray River. This position was created following an examination of the whole Murray system to find an equitable way for Victoria and New South Wales to share its waters.

Developing the rivers west of the Great Dividing Range was vital to the colony's future. During the 1890s McKinney undertook a range of work in the dry Western Division of the colony, where the activities of the Water Conservation Branch were chiefly focused. McKinney was involved with the development of the proto-irrigation schemes operated by the Irrigation Trusts at Hay and Balranald on the Murrumbidgee, and at Wentworth on the Murray. With F.W. Ward he completed a six-week survey along the Darling River to identify suitable locations for locks and weirs. Among his major engineering works were the Willandra and Middle Billabong Weirs on the Lachlan River, the Yanco Cutting in the Riverina, and the weir at Bourke on the Darling River. On the Macquarie River he was responsible for the Warren Weir, and on the Lachlan River a self-acting flood-gate in Lake Creek. This flood-gate maintained a permanent water supply into Lake Cargellico. The Branch also was in charge of innumerable surveys of the major rivers for flood mitigation works, for water supplies to towns and to mining settlements (for hydraulic sluicing), and for improvement works on coastal rivers. After 1896 the Branch administered the long-awaited Water Rights Act, and issued licences under the Act. McKinney was directly and indirectly involved with all these activities. In addition, his many years of field work resulted in the first map of the Murray-Darling Basin published in 1900.

McKinney was passionate about reducing the risks involved in farming operations, and to this end he was dedicated to promoting irrigation development in the colony. In 1891 he drew up a plan for a canal to irrigate the northern bank of the Murrumbidgee. However, the 1890s were years of economic depression and drought, and McKinney believed that 'political inertia' made it difficult to achieve his aim within the government service. He left the Public Works Department in 1901 and, with Robert Gibson, a grazier in the NSW Riverina, promoted a private irrigation scheme from the northern bank of the Murrumbidgee. In 1906 the NSW Government eventually adopted a modified version of this proposal, which it developed and operated as the Murrumbidgee Irrigation Scheme.

Between 1883 and 1912, McKinney published nine papers on irrigation in the Journal of the Royal Society of New South Wales, as well as numerous technical reports for government, and popular articles. He also gave evidence before numerous public inquiries into water conservation and irrigation.