Break O'Day State Emergency Service unit director Phil Dunne has confirmed there is still no safe access in or out of St Helens and Binalong Bay remains isolated.

Mr Dunne urged people not to attempt to drive through flooding as it is not safe.

Several roads have been closed, leaving people stranded in the popular tourist destination.

Several sections of the Tasman Highway were destroyed leaving no safe access in or out of St Helens or Binalong Bay, possibly until Saturday.

Major streets and roads became impassable, close to 14 houses received mild flood damage and a number of tourists have been stranded seeking emergency accommodation.

The St Helens District Hospital was forced to close and three patients were transferred elsewhere after inundation and sewage seeped through the floors.

Acting Primary Health area manager Maribeth Harris said it is expected the closed sections of the hospital will reopen on Tuesday.

A Tasmanian daily January rainfall record was broken after Scamander received 278 millimetres of rain in just 24 hours and St Helens was pounded with more than 100 millimeters overnight.

The rain started on Wednesday and kept falling before conditions moderated late yesterday afternoon.

Bureau of Meteorology senior severe weather forecaster Paul Fox-Hughes said the harsh weather was caused by an easterly trough affecting southeast Australia.

‘‘As that low pressure system moves across us, we are likely to see more heavy rainfall,’’ Mr Fox-Hughes said.

‘‘During tomorrow (today) the rain will tail off throughout the day and flood levels could once again rise with further heavy rainfall between 40 to 50 millimeters expected.’’

Rising waters spelt trouble for Ben Lomond Water, which had to shut down its water treatment plant after the Georges River level threatened vital pumps.

Ben Lomond Water chief executive officer Barry Cash said that until the water recedes it is unable to pump and treat additional supplies.

‘‘While we are asking people to conserve water we remain hopeful that supply can be maintained from existing treated storages,’’ Mr Cash said.

The Break O’Day Council has set up a recovery centre at the Portland Hall in St Helens for people looking for a dry place to stay and has asked people not to panic.

Rain has eased on the East Coast but a further 40 to 50 millimetres is predicted to hit the area overnight.

Floodwaters washed away roads in the Scamander caravan park and flooded the local supermarket, while the St Helens Bayside Inn and Chickenfeed were soaked after the main street was 30 centimetres under water.

People can contact the SES on 132 500, but are urged to be patient as all their and council assets in the area are currently deployed and matters will be dealt with on a priority basis.