Summary

This a pleasant walk inside one of Melbourne's restricted access water catchment areas. Being all on roads or tracks, there are few difficulties or hazards, and terrain is mostly moderate.

Description

O'Shannassy weir was first constructed in the drought year of 1914, when Melbourne's water supplies were critically low. The weir was connected to the existing reticulated water system via an aqueduct along the southern flanks of Mt Donna Buang. The weir was enlarged in the 1920s, then complemented in 1927-28 by construction of the larger (3000Ml) O'Shannassy reservoir a short distance upstream.
Both water supply sources continue in service today, but the infrastructure arrangements have altered over the years. With construction of the much larger (200000Ml) Upper Yarra reservoir a short way up the Yarra River in the 1950s, O'Shannassy was linked into the Upper Yarra pipeline system. The O'Shannassy aqueduct was finally de-commissioned in 2005, and is today a popular walking and cycling path. O'Shannassy (named after 19th century Victorian premier Sir John O'Shannassy)also attracted attention in the 21st century for other reasons. In the prolonged drought of 1996 - 2009, Melbourne's water supplies were again critically low, at one stage, 28.9 per cent. But little O'Shannassy reservoir was the only water catchment to maintain 100 per cent capacity throughout the drought, an indication of what you may face in wet weather conditions. Some damage from the 2009 bushfires is visible on this walk. Today, O'Shannassy soldiers on, a little hidden jewel tucked away in the forested ranges.

677 Views

Points of Interest

1. Yarra River

Melbourne's river is at this point only a short distance from its source, and is a small bubbling stream. Not far upriver it can be crossed on stepping stones

2. O'Shannassy aqueduct track

This is the start of the walking track, which avoids the road, though in some places has more challenging gradients. There is also a better chance to see wildlife and different types of vegetation

3. Half way

Actually not quite half way, the distance to the weir is 4.9 km, and this is 2 km. The first hill of note is climbed at this point, and may be slippery in wet conditions

4. O'Shannassy river

Back on the flat, and possibly a good point for a break. From here on, the buried pipeline infrastucture is visible in the valley

5. O'Shannassy weir

The water flows smoothly over the concrete weir as it has now for over a century. This is a good point to rest and enjoy the tranquility. Aside from the water and wind in the trees, blissfully quiet

6. O'Shannassy aqueduct

It's not flat, it actually descends 2.1 feet per mile (620mm per 1.6 km). In any event, we're only on it a short distance, to the gate at No. 11 Road, which climbs more steeply

7. O'Shannassy reservoir

This is the water storage you've walked so far to see. There are roads going off in all directions, but this is the turn-around, they'll have to wait for another day and another visit

8. Works depot

The portable cabin is locked, though the toilet may not be, and this is the only one on this walk. It's also a good foul weather shelter/emergency refuge

9. Caretaker's house

This 1920s caretaker's house has fallen into ruin. The present-day caretaker's residence is a short way down No. 1 Road. This is the last point of interest, it's time to head for home

Features

Drinking water available

Historical interest

Local treasures

Nature trail

Lake, creek, river