In the state budget on Tuesday, the government said it would spend $20 million to truck in sand to key parts of the Adelaide coastline and a further $28 million for a sand recycling pipeline.

Sand along Adelaide's coast naturally moves northward, pushed by wind and wave action, and builds up on northern beaches.

But this results in severe erosion along the city's southern and central coast.

Sand volumes in those areas are currently at their lowest level since measurements began in the 1970s.

The government said improving the health of the state's coast was its "first defence" against the changing climate.

"We are fortunate to have some amazing beaches in this state and it's important we do everything we can to protect them," Environment Minister David Speirs said.

"We recognise the importance of our coastline as the first defence against our changing climate and this investment will build resilience and improve environmental outcomes in a practical way."

The sand replenishment programs are also expected to create 133 direct jobs.

Australian Associated Press