41.3 Runoff into storages
The volumetric value for the line item for the 2010–11 year was 13,341,900 ML. The value applies only to the Southern Basin. Line item includes inflows to Menindee Lake (5,953,853 ML), Hume Reservoir (5,896,814 ML), Dartmouth Reservoir (1,286,467 ML) and Lake Victoria (204,766 ML) within the Murray–Darling Basin (MDB) region.Information from other storages is not available or not relevant to the line item due to cascading effect.
Runoff into storages was calculated based on a water balance calculation using data available for each storage. The inflow into each storage is calculated using the following water balance equation:
Inflow = ΔS + O + E – P – T
ΔS is the change in storage
O is total outflow from the storage
E is evaporation from the storage
P is precipitation on the storages
T is the volume of water transferred into the storage.
Total outflow (O) is calculated using the following equation:
O = Sp + L + D + R
Sp is spillage
L is leakage
D is volume of water diverted from the storage
R is volume of environmental releases from the storage.
Assumptions, Limitations, Caveats and Approximations
To avoid double counting, Lake Victoria spillage, and releases to the downstream river were not considered in the calculations. Calculated volume for the line item may have included unaccounted inflows other than runoff.