Helena River

The Helena River is a tributary of the Swan River in Western Australia. The river rises in country east of Mount Dale and flows north-west to Mundaring Weir, where it is dammed. It then flows west until it reaches the Darling Scarp.

It passes through the western edge of the Darling Scarp between Gooseberry Hill, and Greenmount Hill before joining the Swan River at the southern edge of the historic town, now suburb, of Guildford.

Many of the tributaries of the Helena River are unnamed due to their seasonality and size. However, on the northern side of the catchment Nyaania Creek and on the southern side Piesse Brook are significant in their moving through built up areas which makes them susceptible to urban environment issues.

Upper Helena catchment (i.e. above Mundaring Weir) has on the north side of Lake C.Y. O'Connor (formerly the Helena River Reservoir) a range of named creeks that occur in State Forest no 71 and 13:

In the higher ground the Helena River passes mainly through State Forest or reserve. This has been beneficial for some of the catchment area, as it has been an important buffer between the urban settlements in the Mundaring and Kalamunda areas. The flora of the Helena valley has been recognised as being of importance because of the relative richness.

It is at Darlington, and the locality of Helena Valley that there is housing and agriculture on its banks before it emerges out on to the Swan Coastal Plain.

At Bellevue and Midland the river has historically passed hazardous industrial sites. This includes the Midland Railway Workshops site and the Midland livestock sale yards.

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