AFTER days of anticipation Warragamba Dam has finally reached 100 per capacity and water is spilling over the wall.

Just before 7pm (AEDT), water began gushing down a 100m spillway into a pond below.

The pond acts as an energy dissipater, slowing the water before it flows down the Warragamba River to join the Hawkesbury-Nepean system.

Several kilometres away, the lookout observatory was packed with more than 100 spectators. Some had been waiting there for more than five hours.

"I came with my two boys to have a look," Ingrid Jouke from Glenmore Park said.

"It looks so high and I didn't expect that I'd see these gates open," she said.

"I've heard this spill from the dam can potentially create misery for some people, but maybe they can control how much is released."

Rain hammers NSW

The news comes after a downpour that put NSW on high alert, with three-quarters of the state at risk of flood.

Tumut in southern NSW might again be the focus of flood concerns tomorrow as the wandering band of torrential rain which has soaked much of NSW shifts south.

"It could be a hot spot tomorrow - they are expecting a lot of rain again as the rain band drifts south,'' State Emergency Services spokesman Phil Campbell told thetelegraph.com.au this afternoon.

"The caravan park there has been evacuated twice in three days and they might be doing it again tomorrow.''

Mr Campbell said the other areas being watched intently by the Bathurst and western Sydney's Hawkesbury-Nepean valleys.

"The rain band starting dumping on the central west but the town's really well protected by levees and it's a remote chance they'll get major flooding,'' he said.

"The river can get a half kay or one kay wide but it's not so much a threat to property - the bathurst showgrounds and ovals get covered but homes should be OK.''

Flood damage



"That could change tonight or tomorrow. The rain band is expected to shift to put more rain over the catchment for Warragamba so that would increase the chance of flooding in that north western Sydney fringe.''

The dense, slow-moving rain band is lingering a little longer then expected as it moves up and down NSW, said BoM forecaster Julie Evans.



