Definitions
The total capacity of a reservoir is the amount of water it can hold when full.
However, not all of this water can be used by the SCA to supply its customers. Operational restrictions such as the location of off-takes, and other factors including sedimentation at the bottom of storages, reduce the amount of useable water. The term full operating storage is used to describe the amount of water the SCA can operationally extract from the dams when they are full.
Available storage is the amount of water that is currently available. This information is expressed as a percentage of the full operating storage to reflect that fact that the water available for supply is restricted by the amount of water the SCA can actually extract, not how much the dam holds.
