Sand Collection and Pumping Trials

• Further Information

In 2006–07, the Department for Environment and Heritage began trials to identify suitable methods of collecting sand from different locations for delivery to the pipeline system proposed as part of Adelaide's Living Beaches: A Strategy for 2005–2025.

Sand pumping through the use of pipelines is a straightforward operation that has been carried out successfully in several other locations around Australia. The Department for Environment and Heritage have undertaken several trials in 2006-07 to determine the best way of collecting the sand from the beach and/or near shore seabed.

Collecting sand from Adelaide's beaches is challenging due to the relatively large amount of shed seagrass both on the beach and in the water. This is particularly significant in locations where the northerly drift of sand and shed seagrass is obstructed, such as at the Glenelg and West Beach harbours. This is a challenge for two reasons:

1. Seagrass can interfere with the collection of the sand by blocking the collection equipment; and
2. Seagrass needs to be separated from the collected sand before it is pumped through a pipeline and discharged onto the beach.

The aim of the trials carried out in 2006-07 was to test the efficiency of different collection methods in potential pick-up locations.

The first sand pumping trial began in July 2006 at the West Beach harbour. The trial tested the capacity of a submersible device, called a 'Sand Shifter', to collect sand from the intertidal area (area between low and high tides) of the beach and sand bar south of the boat haven. The rate of sand collection was not as significant as hoped, due to blockages by seagrass in the 'Sand Shifter' device.

These trials undertaken by the Department for Environment and Heritage have shown that the 'Sand Shifter' is not effective in areas where there is a large amount of shed seagrass in the collection area. Therefore, other sand collection methods for these locations have been investigated, including:

• using the dredging equipment that is currently used for harbour maintenance at Glenelg and West Beach to collect sand from the intertidal area of the beach as well as the harbours; and
• using a jet pump system to collect sand from the beach above high water mark, where there is less seagrass matter in the sand.

Discharge point at West Beach		The trial was much more intensive than will be typical of the permanent operation, which will have fewer visual or noise impacts

The results of the sand collection and pumping trials will be used during the development of designs for the future pipeline systems. The designs will ensure that visual and environmental impacts - including noise, odour and water turbidity - are minimised. It is important to be aware that the impacts of the permanent systems will be less than the impacts of the trials. Wherever possible, pipelines and pumping stations will be buried and electrical power will be used instead of diesel fuel.

Further Information

For further information go to Adelaide's Living Beaches: A Strategy for 2005–2025, phone (61 8) 8124 4882 or email metrocoastprotection@saugov.sa.gov.au.