For Lucy Thorsby, there's a fine line between a busy day for her business in Mullumbimby and not being able to get home because of flooding.

The north-eastern NSW town copped almost 300 millimetres in the past three days as the region received another bucketing.

Lismore and other towns in northern NSW have barely got over cleaning up from Cyclone Debbie's aftermath. Credit:Jason O'Brien

That's prompted the Bureau of Meteorology to post a post a warning on Tuesday for minor to moderate flooding for the local Brunswick River and a broader severe weather warning for heavy rainfall.

"We have a captive audience on a day like this," Ms Thorsby said on Tuesday from her Kiva Spa and Bathhouse. "We actually get very busy."