Information Sheet- Water from the North
Background
Climate change and variability in the south west of Western Australia during the last 15 years led to significant public interest in sourcing water from the north of the State.
The Kimberley region has over 60% of the State’s surface water resources due to tropical monsoonal weather patterns. Most of the rain falls in the wet season from November to April when water demand in the southern half of the State is high.
In December 2004 the State Government appointed an independent expert panel to evaluate the technical and financial viability of transporting water from the Kimberley region to Perth and towns on the Perth to Kalgoorlie pipeline. A comprehensive report was published in 2006.2.jpg)
(Photo Courtesy of the Department of Premier and Cabinet)
Four supply options were investigated in detail:
- Pipeline Preferred Option
A pipeline from an off-stream storage on the Fitzroy River running directly towards Perth for 1,900 kilometres before pumping into Canning dam. The Fitzroy River was the preferred water source for this option. - Canal Preferred Option
A canal from a storage dam on a tributary of the Fitzroy, running along the coast for 3,700 kilometres before pumping into Perth hills dams. While the Fitzroy River was the most suitable water source for this option, the panel found that the reliability of this resource for a canal was unacceptably low. - Super-tankers
Two ocean transport concepts were considered. The first was using super-tankers. The Ord Dam was the preferred water source for this option. This was the lowest cost option evaluated. - Towed water bags
The second ocean transport option was to tow very large water bags. This option proved to be highly risky as the technology for bags of this size is not yet developed. The Ord Dam was the preferred water source for this option.
Current Situation
Government has accepted the findings of the expert panel which were released in May 2006. The Premier noted that the projects were high risk, high cost and generally impractical.
The findings of the Panel are summarised in the following table:
| Comparative Issue | Pipeline Option | Canal Option | Ocean Tankers | 0.5 GL Water Bags |
| Design Certainty | High | Uncertain | High | Unknown |
| Reliability of Supply | Acceptable | Unacceptable | Acceptable | Unknown |
| Unknown | Fitzroy | Fitzroy | Fitzroy/Ord | Fitzroy/Ord |
| Length of Delivery Chain | 1900 km | 3700 km | 3000 km | 3000 km |
| Water Quality Issues | Managed | Variable | Managed | Managed |
| 200 GL/year scenario | ||||
| Number of vessels to deliver 200 GL/year | NA | NA | 14 | 35 |
| Time in transit (Days) | 17 | 93 | 14 | 32 |
| Energy Consumption kWhr/kl delivered | 5.8 | 3.7 | 10.5 | 8.6 |
| Greenhouse Gas Produced (Tonnes of CO2 equivalent) | 0.6M | 0.5M | 2.0M | 1.6M |
| Costs from day one (200GL/year) | ||||
| Capital Cost (Billion) | $11.9 | $14.5 | $6.2 | $5.3 |
| NPV Capital Cost (Billion) | $7.5 | $8.0 | $5.3 | $6.4 |
| NPV Operating Cost (Billion) | $1.5 | $1.6 | $5.9 | $4.6 |
| Unit Cost of Water ($/kl) | $5.1 | $6.5 | $5.0 | $5.0 |
| Cost for Demand Matching Scenario (20 GL/year increasing to 200 GL/year over 50 yers) | ||||
| NPV Capital Cost (Billion) | $4.5 | $8.0 | $2.7 | Not Calculated |
| NPV Operating Cost (Billion) | $0.6 | $1.6 | $2.5 | Not Calculated |
| Unit Cost of Water ($/kl) | $9.7 | $20.5 | $6.7 | Not Calculated |
Sustainability Considerations (water tanker option)
Economic | Social and cultural | Environmental |
| Much more expensive than existing sources. | Indigenous Kimberley communities did not support taking water from the region. | Ocean transport has the least adverse environmental impact on the land. |
| Supply could vary with demand. | Incorporating the preferred option would at least double the average household water bill. | Sourcing water from the Ord dam would have less environmental impact than from the Fitzroy River, although lower reaches are important wetlands |
| May require investment in associated infrastructure, including roads and ports. | May inhibit use of water in the region for other purposes including tourism and agriculture. | Most energy intensive option. |
Potential source yield
The Panel examined source options with a yield of 200 gigalitres per annum.
Recognising that demand for this quantity of water does not presently exist, the Panel costed all options assuming a 20 gigalitre per year supply for the first year, growing to 200 gigalitres per year over 50 years. A source of this size could supply water to more than 800,000 houses per year.
Potential cost
The highest cost option was the canal at $20.50 per kilolitre.
The pipeline was half of this cost at $9.70 per kilolitre, followed by transportation by ocean tankers estimated to be $6.70 per kilolitre.
Reliable cost estimates were not available for the water bag option.
The Future
Further to the findings of the panel and Government decisions in this regard, moving water from the north as a supply to Perth is not considered environmentally, socially or economically desirable at this time.
The State and Federal Governments are currently investigating the feasibility of developing these Kimberley water resources to support more irrigated horticulture and other commercial activities in the region. This development could attract substantial investment and enhance employment for local communities.
More Information
Key
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Potential source yield (in 50 year planning horizon)
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Potential cost (2007 $)