An integral flap gate
prevents blowback when introducing material into the system on start-up or when running empty.
An impoundment wall and tidal flap gate
have also been installed in the past two years.
It re-opened 18 months ago after the installation of an impoundment wall and tidal flap gate
When the vault is filled, the upper 35 percent of the stored stormwater is discharged by gravity through a flap gate
into the bypass tunnel.
The harbour work involves the construction of a new wall across the mouth of the harbour and the installation of a steel flap gate
. This, in turn, will be capable of holding back water within the harbour at depths of up to two metres.