Mundaring Weir is situated on the Darling Scarp, about 30 Km east of Perth, in Western Australia. The dam was constructed between 1898 and 1903, to impound the Helena River and deliver water to the thirsty and productive mining regions located inland.

Today, about 100,000 residents and several farms, mines, and enterprises in the Eastern Goldfields, (especially Coolgardie and Kalgoorlie) critically depend on this supply.

Have you ever wondered how big the catchment of the Helena River Reservoir actually is? To find out more about the hydrology and soil properties within the watershed, check out this GIS-based analysis published as ArcGIS StoryMap!