In June 2007, there were 5 East Coast Lows (ECL) off the coast of New South Wales. The first and most severe occurred over Friday 8 and Saturday 9 June. Heavy rain, strong winds and large ocean swells resulted in widespread damage to coastal regions of the Hunter, Central Coast and Sydney Metropolitan areas. The Queen’s birthday weekend ECL developed in a pre-existing trough of low pressure over the northern Tasman Sea. This trough was directing a humid north-east to south-east air stream across north-east New South Wales and there was a weak low analysed just off the coast near Coffs Harbour on Thursday morning. The low moved south along the NSW coast, before moving out into the Tasman Sea on 10 June 2007.
Thunderstorms caused record breaking flooding in Newcastle, with 164.6 mm of rain falling in 6 hours from 3 pm to 9 pm, causing many shops and businesses to flood and hundreds of cars to be stranded or swept away. This storm event is often associated with the grounding of the Pasha Bulker (a 40,000 tonne bulk carrier ship) which occurred on 8 June on Nobbys Beach in Newcastle and was not re-floated until 2 July.
Approximately 6000 people were evacuated from Maitland (near Newcastle) when it was considered a levee may have burst.
In the Hunter Valley it was reported as the worst flooding in 52 years. Major flooding in the Hunter River occurred from 8 – 13 and in the Paterson and Williams River from the 8 – 10. Moderate flooding occurred in the Wyong, Colo and Nepean Rivers.
Ferry services were cancelled on Sydney Harbour due to the weather conditions. The Cremorne wharf collapsed and sank due to large ocean swells. Beaches were eroded at many Sydney locations, due to swells up to 14 metres high. High winds blew beach sand over 100 metres inland. More than 200,000 homes reportedly lost power in the Sydney - Newcastle area due to flooding and high winds. Many thousands of homes and businesses lost telephone services when telephone exchanges were flooded.
A natural disaster was declared in the Hunter Valley and the Central Coast areas with a total of 19 local government areas. There were a total of nine fatalities associated with the storm. Nearly 20,000 calls for assistance were made to the State Emergency Service.
The Insurance Council of Australia estimated the 2007 damage at $1480 million, with the 2012 estimated normalised cost of $1742 million.