Woman falls into three metre deep sinkhole in Melbourne, Australia

The hole where that the woman fell into.

A woman has been rescued from a three metre deep sinkhole that opened up in her backyard in Melbourne while she was hanging up her washing.

The 45-year-old was forced to swim and float in water at the bottom of the sinkhole for about half an hour, until her cries for help attracted the attention of neighbours.

Authorities now believe that the hole was on the site of an old well.

An Ambulance Victoria spokesman said the woman was hanging up washing in the backyard about 11.30am when the sinkhole opened up under her feet.

"The woman told us she was hanging washing out in the backyard at about 11.30 this morning when the ground gave way," Paramedic Stephanie Palamberis said.

"She fell with the dirt and mud, dropping about three metres and landing in waist deep water. At one stage her head was under the water.

The sinkhole in the backyard.

"The woman told us she couldn't touch the bottom of the hole, so was trying to swim and stay afloat, to avoid the risk of further mud collapses.

"The woman managed to attract attention of neighbours after about 30 minutes and emergency services were called."

She was freed from the hole by CFA firefighters and assessed by paramedics. Thankfully she wasn't injured.

A Country Fire Authority statement says that the woman was working at the property assisting an elderly resident with household duties.

She was hanging out the washing when the ground at her feet collapsed.

Springvale CFA Brigade were first on scene and used rope to extricate the woman from the 2-foot wide hole.

Operations Officer Paul Carrigg earlier said that residents had been advised to stay indoors.

"This was a very unusual incident," he said.

"Fortunately the lady has escaped without injury though she was obviously shaken up."

"We have doorknocked all residents in the street and advised them to stay indoors until council engineers investigate further."

A City of Dandenong spokeswoman told news.com.au that the sinkhole was now believed to be an "isolated incident" and on the site of a disused well, which had not been backfilled properly. She said the covering must have eroded over the years.

She said that the council sent some officers to investigate the hole despite it being on private property. "It is the responsibility of the property owners," she said.