The Parkhill Creek Basin covers 460 square kilometres.
Parkhill Creek arises near Dashwood and flows southward and then westward towards Parkhill.
The creek was a former tributary of the Ausable River but it now empties into Lake Huron, at Grand Bend, through a channel constructed in 1892.
Land use is predominantly agricultural, and forest covers approximately 14 per cent of the Parkhill Creek Watershed.
Wooded areas are concentrated in the Parkhill Creek valley, particularly downstream of McGillivray Drive, several kilometres on either side of the Parkhill Dam. The remaining woodlots are scattered at the backs of farms.
The Parkhill Creek Watershed has one of seven integrated climate and water monitoring stations in Ontario. There is considerable interest in findings from this station, as this watershed with tightly bound clay soils may behave differently to future flood and drought scenarios compared to watersheds with soils that have better infiltration.