Rivercare groups ?caused erosion
By BELINDA SCOTT
LISA Seccombe was horrified when she saw the huge chunk of fertile riverbank chewed out of her paddock by the Orara River in the recent flood.
And she says river restoration work carried out by Rivercare groups is to blame for the sudden and savage erosion of the bank.
The flood tore away about 80 metres of fence, at least one quite large tree and a 50-metre deep semi-circular 'bight' of pasture, leaving a crumbling bank at the edge of a two-metre vertical drop into a side channel of the Orara River.
The eroded bight is adjacent to a rock and log wall built by Rivercare crews to keep water flowing through the main river channel and divert low river flows away from the side channel.
Mrs Seccombe said the bank had been untouched by river erosion in the 30 years the Seccombe family had owned the land at Karangi.
She said while the flood had prevented the family from crossing the river to see what was happening at the site, she thought the work on the Rivercare rock wall had created a whirlpool which had carved out the bank.
"The side effects of the work have created a big mess," she said.
"There are about 30 metres by 30 metres of raw dirt and the next flood will see the same thing happening again it looks like a big volcano crater," she said.
"We hear about the good things Rivercare are doing, but this looks like a meteorite has dropped in the ground and it's taken the fence as well."
The Seccombes run horses and cattle on the six-hectare Karangi property.
Catchment officer for the Orara River, Tony Broderick, who will meet Mrs Seccombe on the site this morning, said he agreed substantially with the whirlpool theory.
He said catchment management engineers were working on plans for a rock wall and a deflection groyne with a series of radiating pins (poles hammered into the riverbed) and this would be combined with some battering of the bank to promote deposition and prevent further erosion at the site.
But he said a look at the bigger picture after the recent flood showed that the work being carried out by Coffs Harbour City Council and Orara Valley Rivercare was succeeding in its aims of trapping sediment and depositing gravel in the side channel, sending water back to the main channel, forming good habitat pools and reducing riverbank erosion in the Skewes Quarry area at Karangi.
"Unfortunately any erosion sites are much more noticeable than the deposition sites, but they are there," he said.
"This is a 20-metre length of river over a kilometre-long site. The rest of the works have held up really well and there is no damage anywhere else."
Mr Broderick said gravel extraction from the 1970s had led to the erosion of the riverbed and banks and created the new shortcut meander channel and the rehabilitation work was to turn this situation around.