Perth
41.3 Runoff into storages
Supporting Information
Total volume of runoff into each urban supply storage during the 2010–11 year within the Perth region is provided in the following table.
Storage |
Runoff (ML) |
Canning |
3,604 |
Churchman Brook |
561 |
Mundaring |
72 |
North Dandalup |
947 |
Samson Brook |
650 |
Serpentine |
1,527 |
Serpentine Pipehead |
|
South Dandalup |
3,988 |
Stirling |
6,215 |
Victoria |
166 |
Wungong |
1,530 |
Total |
19,260 |
Quantification Approach
Data Source
Provided by
Method
Runoff into surface water storages used for urban water supply was calculated based on a water balance calculation using measured data collected at each storage. The runoff into each storage is calculated using the following water balance equation:
Runoff = ΔS + O + E - P - T
where:
ΔS is the change in storage
O is total outflow from the storage
E is evaporation from the storage (line item 42.1)
P is precipitation on the storage (line item 41.1)
T is the volume of water transferred into the storage from the urban water system (line item 41.4)
Total outflow (O) is calculated using the following equation:
O = L + D + R
where:
L is leakage from the storage (line item 42.3)
D is volume of water diverted from the storage (line item 42.6)
R is volume of releases from the storage (line item 42.5)
Assumptions, Limitations, Caveats and Approximations
The evaporation and precipitation data for each storage used to calculate runoff was estimated by the Bureau. The assumptions and limitations associated with these data also apply here.
Uncertainty Information
The uncertainty estimate was not quantified.