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Perth

                                                                                                   

Future prospects

                             

Future prospects   


The table below shows that there is a deficit of available water assets over water liabilities and future commitments that is expected to be settled within 12 months of the reporting date.

Volume (ML)
Less water assets not available to be accessed, taken or delivered
Dead storage 42,810
Inactive storage(1) 71,633
147,133
(19,597)
Less future commitments expected to be settled within 12 months of the reporting date
Expected diversion of surface water allocations (public water supply) 100,000
Expected diversion of surface water allocations (irrigation scheme supply) 50,000
Expected diversion of other surface water 45,000
Expected extraction of groundwater allocations (public water supply) 165,000
Expected extraction of other groundwater 300,000
Expected extraction from private bores 80,000
other
Surplus / (deficit) of available water assets over water liabilities and future commitments expected to be settled within 12 months of the reporting date (759,597)

(1) Inactive storage is the minimum operating volume for reservoirs below which no water is released or abstracted

The expected diversions and extractions are based on abstractions made during the current reporting period. However, the Western Australian Minister for Water announced in November 2010 an additional 45,000 ML allocation for groundwater extraction for urban supply. This increase in groundwater allocation is offset against a similar decrease in surface water allocation. Much lower than average rainfall in the period July to October 2010 has resulted in lower reservoir levels across the region compared to previous years. As a consequence, less surface water is available in the region for urban supply.

Based on historical data, future inflows to the region are likely to be between 100,000 ML and 200,000 ML. Net groundwater recharge from rainfall is estimated to be between 700,000 and 900,000 ML. Inflow of desalinated water is estimated to be 50,000 ML for the next reporting period.

However, it is uncertain whether the deficit of water assets over water liabilities and future commitments will be met with the 2010-11 inflows and recharge.