Lake Eppalock is an Australian reservoir in North Central Victoria about 130 kilometres (81 mi) northwest of Melbourne. It was formed by the construction of a major earth and rockfill embankment dam, known as Eppalock Dam, with a controlled chute spillway across the Campaspe and the Coliban rivers. The lake is situated between the regional population centres of Bendigo and Heathcote and serves as a major water storage facility for both places, as well as the Campaspe irrigation district. The lake also serves as a popular sports and recreational facility.

The Campaspe River, an inland intermittent river of the north–central catchment, part of the Murray-Darling basin, is located in the lower Riverina bioregion and Central Highlands and Wimmera regions of the Australian state of Victoria. The headwaters of the Campaspe River rise on the northern slopes of the Great Dividing Range and descend to flow north into the Murray River, Australia's longest river, near Echuca.