Perth

This line item refers to leakage from major reservoirs within the Perth region.

Total annual seepage at each reservoir, where seepage data are collected, during 2009-10 is given below.

Data source

Water Corporation: Operational Data Storage System.

Data provider

Bureau of Meteorology.

Method

Instantaneous seepage data (L/s) are measured at reservoirs within the Perth region on an approximately daily basis. These data were inputted to Hydstra and converted to daily volume data (ML) in order to determine the total annual seepage (in ML) at each reservoir.

Uncertainty

Ungraded.

Approximations, assumptions, caveats/limitations

• Seepage data are only collected at approximately half of the reservoirs within the Perth region. It is assumed that no seepage has occurred at the remaining unmetered reservoirs. Consequently, the reported leakage volume of 158 ML is likely to be an underestimate.
• It is assumed that the dam seepage measuring points reflect the total seepage from the reservoirs.
• These data were not quality coded. Significant ‘spikes’ in the data (i.e. where daily data were orders of magnitude different to daily data collected before and after the spike) were removed from the datasets for the calculation of total seepage volume.