Draining Melbourne's north-western suburbs, this river has formed a potent symbol of the metropolitan social divide. Rising west of Lancefield in the foothills of the Great Dividing Range, the river runs 130 km to join the Yarra River and Port Phillip Bay. Beginning as Deep Creek, the Maribyrnong gathers Emu Creek, Jacksons Creek (south of Bulla), Taylor's Creek (near Keilor), and Steeles Creek (near Essendon). Subject to tidal influence up to the Canning Ford at Braybrook, the river estuary was named the Saltwater River in contrast with the broader and deeper river which flowed in from the east, and which offered freshwater nearer to the Bay. Both Charles Grimes (1803) and John Batman (1835) nominated the environs of the Freshwater River as superior for settlement. Whereas the Freshwater took the name 'Yarra' (Aboriginal, it seems, for 'ever flowing'), the Mirring-gnai-birr-nong (or Maribyrnong) River was soon dubbed the Saltwater. Author Richard Howitt used both 'Salt-water' and 'Mariburnong' when he crossed near the junction with the Yarra in 1844, and surveyor Robert Hoddle mapped the junction of the 'Saltwater' and 'Yarra Yarra' in that year. Maribyrnong Street is shown along the river in the 1849 survey of 'Footscray Township Salt Water River'. The river, at least in its lower reaches (the river estuary), remained known as the 'Saltwater' until 1913.
Early pastoralists favoured the open grazing country of the Maribyrnong's upper reaches, with their freshwater tributaries, but the lower, saltwater stretch initially repelled European settlers. British precedent, official colonial policies and private opportunism soon transformed the Saltwater and the Yarra below Melbourne City into an industrial sump. From the boiling-down era of the 1840s onwards, abattoirs and their attendant noxious trades crowded the banks and discharged their untreated waste to the rivers. Dry summers, when the Maribyrnong often completely ceased to flow, compounded the problems of pollution. The Melbourne City Council established abattoirs at Flemington, and relocated its cattle yard to Newmarket in 1860. Redevelopment of the Lower Yarra by the Melbourne Harbor Trust from 1877 saw many more noxious trades transferred to the Saltwater River at Footscray and Kensington, and the direct cut Coode Canal (1886) opposite Newport further diverted attention from the Saltwater. The foul air and filthy rivers branded Melbourne as 'Marvellous Smelbourne', but locally the western suburbs were stigmatised as 'Worst Smelbourne' or 'Worst Smelldom'. Local agitation for the removal of the trades began in the 1880s but had little success for a century. Sewering of the city abattoirs and the noxious trades at Flemington and Kensington in the early 1900s led to some air and river improvement, but the expansion of the chemical and defence industries before and after World War I, and of the noxious trades at unsewered Braybrook, soon set the river back.
The Maribyrnong had been one of Melbourne's most popular fishing grounds in the 19th century. Angling clubs flourished in the surrounding suburbs, as did the enthusiasm for swimming, boating and rowing. The Victoria Rowing Club held its annual regatta in the Lower Yarra and Maribyrnong River until the early 1880s when pollution forced removal. Attempts were made in the 1900s to renew recreational use of the river: the Essendon River League (1906) succeeded in having the Saltwater renamed the Maribyrnong in 1913; private entrepreneurs operated pleasure launches from Melbourne to the Wine Hall, and to the Riverview Tea Gardens at Avondale Heights; and Melbourne's Henley-on-Yarra was mimicked by a Henley-on-Maribyrnong in the 1930s. But the river and valley declined during World War II and the postwar years during another wave of heavy industrial development. Passive entertainments and the motor car drew activity and attention away from the river.
In the 1970s, in the context of the nature conservation movement, local activists successfully engaged governments to clean up the river. Even then the Yarra, the focus of metropolitan press campaigns to 'Give the Yarra A Go', received most attention. However, the federal Whitlam (Australian Labor Party) Government of 1972-75, and successive State governments from 1972 funded major improvements to the river and valley, and Victoria's Environmental Protection Authority began to police discharges. Local groups pressed for improvements, acted as watchdogs, and attempted to transform community attitudes: the Footscray Historical Society initiated the Saltwater River Festival with explorer Charles Grimes as the historical focus from 1974; river cruises were resumed from 1979; pollution controls, dredging and de-snagging encouraged the return of the fish and of anglers; a comprehensive Maribyrnong River Plan was launched in 1984; and the Friends of the Maribyrnong Valley was formed in 1986. Melbourne's long unloved and unsung 'other river' was enjoying a rebirth.