Northern NSW to cop more days of rain

The Bureau of Meteorology says a trough of low pressure lingering near the northern coast is expected to persist for the next few days, with the chance of a potentially severe thunderstorm on Thursday.

Another trough is developing over the northern inland and the two systems will bring more rain to the east and north for the remainder of the week and continue into the weekend.

The BOM is warning of the potential for flash flooding as rain hits already saturated soil as well as catchments, rivers and creeks.

NSW Deputy Police Commissioner Mal Lanyon, who is the northern NSW flood recovery co-ordinator, is hoping the heavy rain does not eventuate.

The clean-up in Lismore is a massive undertaking, with debris piled up outside thousands of gutted homes.

Only 40 to 45 per cent of the waste had been removed from Lismore city, which was inundated with more than 14 metres of floodwater on February 28.

"We've taken over 15,000 truckloads of waste to waste exchange stations and we've been operating about 370 trucks a day - and they're semi-trailers," Mr Lanyon told Sydney radio 2GB on Thursday.

"A huge amount of waste is going so it's a massive job. It's a big job and a lot to do but I'm very happy with the progress."

The floods have left nearly 1500 people in emergency accommodation and 4000 homes uninhabitable.

The BOM is predicting at least another week of heavy rain and thunderstorms along the east coast from Sydney, the Hunter and up the Mid-North Coast and the Northern Rivers - all areas that remain saturated by the recent spate of torrential rain.

Rainfall of 100-150mm is tipped to fall over the next five-to-seven days but some parts could see more than 200mm, around the Hunter and Mid-North Coast and up towards the Northern Rivers.

People living in communities affected by the recent flooding are being warned to keep an eye on forecasts, with the BOM poised to issue a flood watch for parts of the Central and Northern Coast.

Australian Associated Press