Ord

The volume recognised in the water accounting statements (93 ML) represents the volume of leakage from the dam wall of each of the surface water storages in the Ord region during 2009–10. The Lower Ord River (regulated channel) does not have a metered leakage.

The breakdown of leakage from surface water storages is provided in the table below.

Data source

Water Corporation Operational Data Storage System database.

Data provider

Bureau of Meteorology.

Method

Instantaneous seepage data (L/s) are measured at water reservoirs within the Ord region on a daily basis. The measurements are taken at the dam wall. These data are put into Hydstra and converted to daily volume data (ML) in order to determine the total annual seepage (in ML) at each reservoir. The total leakage is the aggregate of seepage for each monitoring site.

Uncertainty

Derived from measured data. Ungraded.

Assumptions, approximations and caveats/limitations

• Seepages are estimates only, based on measurements at seepage monitoring points below dam walls. Total leakage is based on the aggregation of seepages for each site at each dam. It is assumed that the dam seepage measuring points reflect the total seepage from the dams.
• 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 data-sets for the calculation of total seepage volume.