Organs Road, Bulli, is a pleasant Illawarra street with a gentle hill, a small bridge over a creek, and a florist on the corner.

Not much seems unusual, although the neighbours appear to be on better terms than the residents of many other streets.

But some parts of the street experience flooding with a regularity that residents believe turns the "one-in-100-year" estimate on its head.

And it is not the only street in the Wollongong area that can make such a claim.

After you've been flooded three times, the sound of heavy rain on the roof at night brings with it anxiety and fear, not a soothing soundtrack to smooth the path to sleep.

In some areas, residents are openly wondering whether they can expect to be flooded every time there is a heavy storm.

Diane Stewart, who lives in Organs Road, is now one of them. Her house was flooded in 1998 and again in March this year.

"How many one-in-100 year floods have we had in the past 16 years?" she asked.

As is often the case in Wollongong, flood damage in March was very localised.

Many Organs Road residents lost their cars, either when they floated away or were written off by water damage. Several had floodwater go through their houses.

Businesses are affected too - Bunches florist has flooded, Parsons funeral home has flooded.

In Organs Road, and elsewhere, many residents say a lack of adequate maintenance on the creeks has caused them to become overgrown with vegetation that reduces creek capacity and makes them more prone to blockage.

Ms Stewart showed the Mercury where Whartons Creek was overgrown with lantana and other scrub.

"This used to be heaps wider," she said. "If you look down there you see all the junk that's down there. I know it's green ... but it's junk.

"Ever since the last set of floods, it's just going berserk. That palm has grown since 1998.

"We just want it clean."

After the March flooding, residents asked the council for help cleaning up but were told because the creek was technically on private land, the answer was no.

And when they have tried to get the creek cleared, they have been told that it is private property, that much of the creek is owned by Roads and Maritime Services (RMS), or that clearing does little to help.

Wollongong City Council estimates 40 per cent of creeks in Wollongong are on council land - with the other half on private, including state government agency, land.

Neighbour Robyn Mickelson lost a fence and a car in March.

"Water's not going to flow through the creek because the creek is overgrown," she said.

"The [council] flood management guy told me he needs permission to clear it out.

"He told me the width of the creek makes no difference to us [residents].

"We've got two different fronts - we've got council and the RMS, and neither one of them want to take responsibility."

Perhaps a larger issue than the creek is the tiny culvert that Whartons Creek must pass through to get past the railway line embankment.

Residents say this has been exacerbated by the 2009 extension to the northern distributor. Floodwater stops at the low point between the Bulli shops and the Memorial Drive roundabout, with nowhere to go.

The council's flood plain management plan for the area is finally complete, 16 years after the devastating 1998 floods that sparked the studies.

A questionnaire sent out by the council as part of the flood study found that most people believed managing vegetation along creeks, clearing out waterways, and limiting development on flood-prone areas were the best ways to mitigate flooding in the Collins and Whartons creek catchment.

Organs Road residents are unlikely to get any relief from the management plan soon.

It has two recommendations to mitigate flooding from Whartons Creek, both of which recognise the seriousness of the situation - the installation of a flood deflection levee where Whartons Creek goes under the railway line, and building a bridge on Franklin Avenue to allow much more water to pass.

But these are just "medium priorities", so will be a long way down the funding order.

Projects listed as "high" priorities include a weather warning system, several debris control structures, and planning controls on inappropriate development.

Council manager of infrastructure strategy and planning Mike Dowd said care of the creeks was the responsibility of "whoever owns the land through which the creek passes".

"Council can provide advice and guidance to landowners on appropriate methods of managing creeks to reduce flooding to their and neighbours' properties, however [it] does not undertake works on private land," he said.

Up the hill on Organs Road lives Norman Upton, who has seen many floods stretching back more than 40 years - he used to do a milk run there when he was a boy.

He said the creek was worse today, particularly where it runs under Organs Road. He said the council and RMS needed to work out who would take some action.

"The culvert dams itself up with refuse and is blocked off so the water rises up," he said.

"Up at my place, it's my responsibility, because the creek's actually in my yard. But down here, it's their responsibility - council and RMS."

Roads and Maritime Services officers will meet Wollongong City Council staff next week to try to find a way to solve the flooding problems from Whartons Creek.

The news will please residents, who have raised concerns about the creek for years.

After questions from the Mercury on Friday, an RMS spokesman claimed regular maintenance was carried out on the creek and said RMS would meet with engineers immediately.

‘‘Roads and Maritime Services owns a section of Whartons Creek in a corridor reserved for the future extension of Memorial Drive,’’ he said.

‘‘Regular maintenance is carried out in the area.

‘‘Roads and Maritime communicates regularly with Wollongong City Council about flood management and has organised a meeting with council’s flood engineers next week...’’

In 2005, the NSW government produced its Floodplain Development Manual, which stated its objective was ‘‘to reduce the impact of flooding and flood liability on individual owners and occupiers of flood-prone property, and to reduce public and private losses resulting from floods’’.

In Wollongong, as the Mercury’s Going Under series has shown, many residents fear that more flood liability is being pushed on to them, without mitigation works being done quickly enough to make a difference.

The state government manual makes clear that the ‘‘primary responsibility of floodplain risk management rests with councils’’, with financial and technical support from the state government, as set out in the NSW government’s Flood Prone Land Policy.

But given the costs of infrastructure improvements and mitigation works can run into several million dollars, and councils are rarely awash with unclaimed cash, the state government will usually be involved when works are carried out.

Implementing the Collins Creek flood management plan would on its own cost 10 times the amount Wollongong City Council allocates to stormwater each year, council flood chiefs say.

In a wide-ranging interview on flooding with the Mercury earlier this month, the council’s manager of infrastructure strategy and planning, Mike Dowd, and stormwater and transport services manager Peter Nunn said mitigation works were constrained by budget concerns.

Mr Dowd said creek maintenance needed to be balanced with environmental concerns.

‘‘Our challenge is balancing flood, stormwater, with environmental considerations, because trees and plants and vegetation can hinder, but also can benefit [flood mitigation],’’ he said.

‘‘Our clearing is focused around those potential blockage points of the culverts, not necessarily whole stretches of creek through private or public land.’’

Mr Nunn said the amount of vegetation in a creek did not necessarily determine how it flowed.

‘‘Sometimes cleaning the creeks isn’t as relevant as the community think,’’ he said.

‘‘We maintain it where we can, some we don’t maintain, but some culverts in some creeks are more sensitive than others. So it’s important to look at the ones that are more important and focus on them.’’

Mr Dowd said the council could do more work, but it was a matter of money.

‘‘Where we’re able to, we’d like to be able to do more in terms of making sure that any potential blockage is removed and managed, so that we don’t have that burden of just before or just after a flood event, we have to go and clear things out,’’ he said.

‘‘Resource limitations obviously have impacts on that, and that’s always the standard response you’d hear, but it’s a reality.’’

Mr Dowd pointed to the Whartons Creek plan to illustrate the expense.

‘‘In our report to council we estimated that to implement that plan would be about $20million;  we allocate around $2million to capital investment each year, in stormwater,’’ he said.

‘‘We know that needs to ramp up, but we need to plan as a whole city to identify those sites, and prioritise catchments... to say a creek or culvert in Whartons Creek is equally or more important than one in Tramway Creek, compared to American Creek.’’

Mr Nunn denied the balance too strongly favoured environmental concerns over people.

‘‘The vegetation has an important stabilisation function as well, so if you knocked out all the trees, you’ll get bank erosion; you’re going to get culverts silting up as well,’’ he said.

‘‘Vegetation is also an important function of keeping the creek blockage-free as well, for culverts.

‘‘It’s not a simple matter of cutting everything down, otherwise you’d get all that scour and you’d get a different sort of blockage.’’