It is also clogging up pumps, foot valves and hot water service systems as wash from boating activity and wind moves the sand from beaches and redistributes it along the river.

Murray Watch president Rayleigh Burgess said the problems would become worse when flows returned to the river.

“When the river comes back, all that sand’s going to be washed out and you will end up with a channel in the middle,” she said.

“It’s understandable that recreational river users don’t want to be walking in sludge on the river banks, but they’re not considering the river and they’re not considering the future.

“What we need is some kind of low cost, rubber matting, that can be rolled up and removed when they leave.”

Murray Bridge Water, Land, Biodiversity and Conservation Depart-ment compliance officer Roger Brown said lower river levels and exposed banks that were often rocky meant people were trucking in larger amounts of sand than ever before, sometimes without realising it was illegal.

He referred to a recent incident in the Murraylands where a council pump station had to be broken into and turned off by local residents before it caught alight as it had clogged up with sand dumped on a beach upstream.

“The main thing is to make an awareness raising program - make people aware that you can’t do it,” he said.

The Conservation Department is currently working with the South Australian Environmental Protection Authority and local governments to raise awareness of the issue, and, if necessary, take action against illegal sand dumpers.

There have been several instances of sand bars causing havoc along the River Murray recently.

This includes a sand bar that formed eight feet out from the Long Island Reserve boat ramp last December that had to be dredged, and a houseboat that became stuck on a sand bar in Murray Bridge last week after the driver misread navigation markers.