The Maroondah Aqueduct, Donnelly's Weir and Echo Tunnel are part of the first diversion scheme on the Watts River, completed in 1891, and represent the earliest structures associated with the Maroondah Reservoir.

The aqueduct was the first of a new style of low-maintenance concrete-lined channel constructed by the MMBW, the earlier channels being lined with hand-cut bluestone or granite pitchers.

The Echo Tunnel and Sawpit Creek Weir are early features on the public walking track to Condon's Gully which was a popular destination for visitors to Healesville guesthouses during the early twentieth century. The site continues to be a popular destination for visitors along the aqueduct pathway from Donnelly's Weir.

The caretaker's hut is an example of the typical style of hut constructed for caretakers along the Board's aqueducts to provide temporary accommodation and, from the 1940s, a telephone communication system. (McCann 1993: 83)

Donnelly's Creek Weir is a small weir about 1 metre high, 7500mm thick and 15 metres long across Donnelly's Creek. It is constructed of bluestone and concrete and a metal gate section in the centre. The control wheel for the take-off valve is at the western end of the weir. A picnic area has been established and visitor facilities include toilets, picnic tables, barbeques and a car park. (Supple, 1989)

The Maroondah Aqueduct (inspected at Echo Tunnel and Yarra Glen only) is a concrete lined open channel originally extending 65 km from Maroondah Reservoir to Preston Reservoir, but now in service only between Maroondah Reservoir and Yering Gorge Pumping Station, which feeds water into Sugarloaf Reservoir with several tunnels along its length, and a brick bridge over the Yarra Glen Road. (McCann 1993: 83)

Features on the Maroondah aqueduct system near the Reservoir include the Echo Tunnel through which water passes underground from the resevoir outlet tower at the Maroondah reservoir, the Sawpit Creek Weir (disused), and a low "bridge" over Sawpit Creek comprises three low concrete spans beneath a structure of irregular stone blocks, forming the bridge support for the aqueduct to allow the creek to flow beneath it. Nearby, the creek flows over the remains of the weir, a stepped structure made of similar rock material, apparently designed to prevent silt from blocking the very low channel beneath the aqueduct. (Lindsay bergin, pers. comm.) The place also has a single-room galvanised iron caretaker's hut and associated "maggie" telephone post, and a public pathway running for about 200 metres beside the Maroondah aqueduct at Donnelly's Weir. (McCann 1993: 83)

The place is located on the western perimeter of the Maroondah Catchment, and is surrounded by a plantation of Norfolk pine and Pinus radiata trees. (McCann 1993: 83)

Physical Conditions: Poor

Integrity: Intact