The sand transfer infrastructure includes seven kilometres of pipeline from Glenelg to Kingston Park and two kilometres of pipeline from Torrens Outlet to West Beach dunes. There are also two main pump stations, three booster pump stations, 16 discharge stations and a relocatable sand collection unit.
Sand is scraped from the beach surface using a land plane and brought to the sand collection unit where it is screened to remove stones, seagrass wrack and rubbish, then mixed with seawater to form a sand-slurry (70% water, 30% sand).
The sand slurry is pumped southwards through the pipeline to discharge stations at southern beaches where it is discharged at the back of the beach, at the toe of the dune or the base of seawalls. The sand settles out from the slurry forming a low, wide stable mound and the excess water returns to the sea.
When sand has built up at one discharge location, the sand slurry discharge can be redirected to another discharge location. At the end of each pumping session the pipeline is flushed with plain seawater to remove remaining sand.
The discharged sand is gradually spread out by waves and moved northwards along the beach (known as littoral or longshore drift) to provide protection to the foreshore.
Where seagrass has built-up on the donor beach it is removed or set aside to ensure that mainly sand is collected and brought to the sand collection unit.
When does pumping take place?
Sand pumping operates mainly between autumn and spring. Pumping may occur any time between 7:00am and 7:00pm from Monday to Saturday.
As with sand carting, pumping is scheduled to avoid work in summer and school holidays when beach usage is high.
The duration of each sand pumping campaign depends on the amount of sand required to be pumped. This is determined by surveys of beach heights and calculations of beach volumes in relation to the minimum beach and dune buffer requirements.