Victoria Dam
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 | Current storage at Victoria Dam |
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The Victoria Dam was built to supply water to the adjacent hills suburbs of Lesmurdie and Kalamunda and to augment supplies of water to the Perth metropolitan area during times of peak demand.
The dam has a catchment area of 37 square kilometres and a reservoir capacity of 9.5 million cubic meters.
The Victoria Dam was opened on 22 November 1991 by the Hon. Ernie Bridge J.P., M.L.A., Minister for Water Resources.
Original Victoria Dam
The original Victoria Dam on Munday Brook, about 25 kilometres south-east of Perth, was completed in 1891, forming the source of Perth's first permanent city water supply. The dam, pipelines and associated reservoir at Mt Eliza in King's Park were constructed and operated by a private company, the City of Perth Waterworks Company. Following widespread complaints over water availability and pressure, together with the high incidence of typhoid in the city, the entire scheme was purchased by the Government in 1896.
At the time there were a number of timber mills and towns within the catchment. Poor sanitation, combined with contamination from animal husbandry and grazing activities are believed to have been the cause of the water quality problems. The solutions adopted included appointing a catchment warden to police the hygiene regulations, together with a system of channels and diversion structures to separate clean and polluted waters.
At various stages remedial works were carried out at Victoria Dam to improve the structure. Works were generally aimed at increasing the spillway capacity and at reducing the seepage through the dam wall. The seepage was leaching lime and thus reducing the strength of the concrete and forming voids. In 1966 major remedial works were undertaken. A reinforced concrete upstream facing, varying in thickness from 300 to 450 millimetres, was installed to reduce seepage through the wall. A drainage system was installed to intercept any water leaking past the new facing. These works were successful in reducing seepage through the wall.
As part of the Water Authority's on-going dam safety and surveillance program, a safety review of Victoria Dam concluded in 1988 that the dam did not have acceptable levels of safety under modern design criteria for flood and earthquake loadings.
The concrete in the original dam is of such poor quality that the dam could not be adequately rehabilitated. The dam was decommissioned in April 1990 and in October 1990 was partially demolished using explosives. Only sufficient portions of the wall were removed to allow free passage of flood overflow from the upstream New Victoria Dam. The remainder (and majority) of the original dam has been preserved as a relic of Perth's first water supply.
Victoria Dam
Roller Compacted Concrete (RCC) was used to construct the Victoria Dam. RCC combines the advantages of a concrete dam, that is a relatively small volume of erosion-resistant material, together with the very efficient plant-intensive methods used to construct earthfill and rockfill dams. The evolution of RCC dams stemmed from a realisation that the future of traditional concrete dams were uneconomic due to the inefficient and labour intensive method of construction.
Victoria Dam was the first RCC dam in Western Australia and the fifth RCC dam completed in Australia.
Principal statistics
| CATCHMENT | |
| Catchment area | 37 square kilometres |
| Average annual rainfall | 1150 Millimetres |
| At full supply level | R.L. 202.0 metres A.H.D. |
| capacity | 9.5 million cubic metres |
| surface area | 77 hectares |
| At maximum flood level | R.L. 203.7 million cubic metres |
| surface area | 86 hectares
|
| DAM WALL | |
| Type | Concrete gravity |
| Height above foundations | 52 metres |
| Height above scour outlet | 36.9 metres |
| Crest level - left abutment | R.L. 203.1 metres A.H.D. |
| Crest level - right abutment | R.L. 203.7 metres A.H.D. |
| Crest length | 285 metres |
| Crest width | 8.8 metres |
| Total volume of concrete | 134 500 cubic metres |
| Volume of roller compacted concrete | 121 000 cubic metres |
| Volume of concrete facing elements | 13 500 cubic metres |
| Volume of excavation for foundations | 100 000 cubic metres
|
| INTAKE TOWER | |
| Height | 39.6 metres |
| External width of stem | 8.0 metres |
| Internal width of stem | 6.5 metres |
| Number of offtakes | 4
|
| OUTLET CONDUIT | |
| Diameter of conduit | 1.2 metres
|
| SPILLWAY | |
| Type | Overflow section on dam |
| Discharge capacity | |
| at R.L. 203.1 metres A.H.D. | 280 cubic metres per second |
| t R.L. 203.7 metres A.H.D. | 620 cubic metres per second |
| Main spillway crest length | 65 metres |
| Main spillway crest level | R.L. 202.0 metres A.H.D. |
| Auxiliary spillway crest length | 65 metres |
| Auxiliary spillway crest level | R.L. 202.3 metres A.H.D. |
| Stilling basin length | 65 metres |
| Stilling basin floor level | R.L. 164.9 metres A.H.D. |
Catchment management
As the reservoir provides drinking water to the Perth Metropolitan System recreational activities are not permitted on the reservoir and an exclusion zone exists around the reservoir and streams flowing into it.
Due to the limited public facilities provided, the Corporation restricts public access to the site. Pedestrian access is permitted at all times.
The upper car park areas are open to the public on weekdays from 8:00 am to 5:00 pm. The public can access the dam from this car park via the signposted walk trail, a 300 to 400 metre walk. On weekends and public holidays both security gates are closed, including the entrance gate located two kilometres from the dam site. However, walkers can access the dam via the signposted walk trails. The public are directed to the walk trail rather than the service road. This road is much steeper and longer than the sign posted walk trail, has no footpath, is dangerously curved and is used by trucks and Corporation vehicles.
Your safety & the security of our water services
For your own safety when visiting our sites please ensure that you confine your movements to the signed and formed pathways, roads and recreational areas. Please recognise that there are uneven surfaces and walking hazards which may exist in the area due to the nature of its design and construction, and exercise caution at all times when moving about the area.
Please do:
- Follow and comply with all directional and informational signs.
- Always monitor the whereabouts of children as they explore the site.
- Report all safety hazards to the onsite Ranger, Staff or 13 13 75 (all hours)
- Report all unsafe, criminal or suspicious behaviour to the Ranger, Staff or 13 13 75 (all hours)
Please do not:
- Climb walls, fences or bridges.
- Climb on pipework or other operational infrastructure.
- Deface safety and security signs.
- Trespass into signposted operational and "No Entry" areas.
- Attempt to operate operational taps, valves or controls.
- Block emergency and operational access gates and roadways with vehicles.
- Bring your pet, as domestic animals are prohibited from all drinking water catchments.
