The council is considering stronger action against the developers of a May Street subdivision following heavy rain that washed large sediment loads into the Goulburn wetland on Friday night.
Residents registered 55mm during a torrential downpour that started at 5pm Friday and continued until 9pm. Goulburn Airport received 60mm in the 24 hours to 9am Saturday.
For the third time since August, heavy rain washed sediment from a cleared subdivision at 99 May Street, below Rocky Hill, into the wetlands below. Vegetation was cleared from the area late last year to make way for the development.
Friends of Goulburn Swamplands (FROGS) volunteer Heather West said it was very distressing after all the hard work people had devoted to restoring the wetland.
"All the plants that Australian Plant Society had put in on the hillside leading to the top picnic table have been uprooted," she said.
"...The road in front of the picnic shelter will also need to be replaced as water got in underneath and lifted it."
The rush of water also scoured out areas around the wetland, washed away bark chip and filled the swampland with sediment that volunteers feared had upset the ecosystem.
Council general manager Warwick Bennett said staff had been talking to the developers for four months about the runoff. In early November the council issued a stop-work order and penalty infringement notices against the company and ordered a host of remedial measures to contain water from the sloping land during heavy rain.
At that time, Mr Bennett said the company had been very proactive with compliance and had implemented additional measures of its own volition.
But on Monday, this view had changed.
"We don't believe they have addressed it as well as they could and there's a hell of a lot of work needed on the site. It is very frustrating," he said.
"The detention ponds are inadequate. Unfortunately for them it has been an extremely wet season but that is not ours or the neighbours' problem. They need bigger pumps to get the water away."
He told The Post that the council was considering its options following Friday's deluge, including another fine. But legal action was also a possibility, as fines were "a lot more substantial" if the case was proven.
A neighbour, Judith Ferneley, photographed the rush of muddy water that flooded May Street on Friday afternoon, which was flowing into the wetland.
She noted that the developers had pumped out the onsite detention dams earlier on Friday ahead of the forecast rain. While they did not burst, Ms Ferneley noted that the dams appeared badly damaged.
The developer has declined comment. However it's understood they have worked with neighbours to repair damage and clean up the wetland. The 28-lot subdivision will be known as The View.
Mrs West appreciated the company's help but said the wetland had suffered damage. On Saturday she stood in an area once partially covered in plants that had been scoured out by the rain.
A local Australian Plant Society spokesperson said plants had been uprooted and a "significant number" had died from being covered in clay. The recent damage had exceeded that from previous heavy rain and had impacted hard infrastructure.
"The disheartening effect of such repeated damage to gardens which otherwise have been showing such promise can hardly be expressed," she said.
FROGS Landcare is preparing a report for the council and the Environmental Protection Agency.
Mrs West said she'd prefer that heavy runoff from the subdivision was piped directly to the Mulwaree River rather than into the wetlands.
"If the bottom of the wetlands is filled with silt it makes it more shallow and flows out into the Mulwaree Ponds when it fills up," she said.
"...We'll get the water tested because we don't know what effect (the silt) will have on the ecology. It is an ecosystem, supposedly, but the topsoil from the hill is having an impact."
Volunteers will be cleaning up at the site on Wednesday and Mrs West says more helpers are needed.
Meantime, Mr Bennett said the council was tallying the damage from Friday's storm. It appeared to be confined more to the Goulburn and Tarago areas.
Goulburn has received 123mm so far this month, with 118mm of that falling on Friday and Saturday, according to the Bureau of Meteorology.
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