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The pipeline

The pipeline is made of high density polyethylene (HDPE), 315mm or 355mm in diameter, with a wall thickness of 30mm. The wall thickness has been designed to accommodate wear from the sand and seawater mixture that is pumped through it.

The pipeline is laid in trenches, with the top of the pipe approximately 0.7 metre below the ground surface. In a few locations the pipe is much deeper, where directional drilling was used to install it under infrastructure including stormwater outfalls and trees. Where the pipeline is in the beach, it is laid at -1.25 metres AHD (Australian Height Datum). The pipeline is protected by existing seawalls or its depth being below the depth of erosion during storms.

The pipe used to transport the seawater to the sand collection unit is also made of HDPE, approximately 400mm in diameter. Where possible it is in the same trench as the sand pipeline.

Main pump stations

The main pump stations are located at Glenelg and West Beach and measure 12.3m x 6.4m. The top of the station at Glenelg is level with the nearby stone wall. The station at West Beach is underground and the roof is level with the surrounding natural surface.

A vent 2m x 1.5m and 4m high extends from the roof of the stations to allow for air intake and outflow to cool the pump and associated equipment. The pumps are electrically operated, quiet and have no exhaust emissions.

The surrounding area of the main pump stations have been enhanced to reduce visual impacts.

Booster pump stations

The booster pump stations are underground and measure 12.3m x 6.4m.

The station surface is level with the surrounding dune surface or footpath level. At Whyte Street, Somerton Park and Wattle Avenue, Hove the stations are adjacent to the footpath, allowing easy access for people to use the station as a viewing platform.

A vent 2m x 1.5m and 4m high extends from the roof of each station to allow for air intake and outflow purposes to cool the pump and associated equipment. The pumps are electrically operated and are quiet with no exhaust emissions.

A discharge station is incorporated into the booster pump structures to allow sand and seawater mixture to be discharged onto the beach at these locations.

The road, footpath and seawall that were removed to allow for construction of the booster pump stations were reinstated after construction was completed.

Discharge stations

The discharge stations were installed underground and are concrete boxes that measure 1.9m x 1.7m x 1.5m in depth.

Where placed within the dunes the top of the stations are level with the surrounding dune surface. Where placed adjacent to roads or rock seawalls the top of the stations are level with the adjoining footpath.

A pipeline was installed underground in the dune or within the rock seawall to link the discharge station to the discharge site at the top of the beach. Pipe extensions allow for wider distribution of the sand and seawater mixture over a larger area at each discharge site.

Each discharge station contains a removable pipe section to allow a 90 degree pipe bend to direct the sand and seawater mixture to the beach.

Sand collection unit

The sand collection unit is stored off-site and is brought to the beach when sand pumping is required. It is placed within a temporary fenced area.

Sand is collected from the beach using a land plane which travels the beach scraping thin layers of sand from the surface, it then brings the sand to the sand collection compound area. Sand is then screened using a trommel to remove stones, larger shell fragments and other debris and mixed with seawater and pumped to the southern beaches.

Water intake unit

Submersible pumps are located at the Adelaide Shores Boat Harbour and at the end of the Glenelg jetty to supply seawater to the sand collection unit to be mixed to form the sand and seawater mixture. At the end of each sand pumping session, seawater is pumped to flush the pipelines of any sand sediment.

The seawater pumps have been designed to operate in low and high tide, and stormy conditions. They include screening to prevent being impacted by local water conditions and to avoid seagrass getting into the seawater system.

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