Shoalhaven River banks at Bomaderry stabilised thanks to Shoalhaven Riverwatch and Green Army

SHOALHAVEN Riverwatch and Green Army volunteers have combined to continue the work of legendary Shoalhaven River conservationist and campaigner Charlie Weir.

Over the past 20 years Charlie has planted more than 100,000 mangroves and 25.000 casuarina trees to help stop erosion of the river banks.

On Charlie’s retirement, Peter Jirgens has taken over as co-ordinator/project manager and with a busy band of volunteers the work continues.

In its latest project the group has joined forces with Green Army volunteers to plant more than 600 mangroves and 50 casuarina trees on Bomaderry farmer John Bryce’s property to stabilise the river bank.

The massive work has been undertaken on a stretch of the Shoalhaven River from near the bridge, east to Bomaderry Creek.

Under the guidance of project managers Ian Bice and Ross Portener from Riverwatch and co-ordinator Peter Swanson from Conservation Volunteers Australia, the volunteers with have undertaken the work.

Shoalhaven Riverwatch co-ordinator Peter Jirgens and Bomaderry farmer John Bryce

Shoalhaven Riverwatch co-ordinator Peter Jirgens and Bomaderry farmer John Bryce

Riverwatch co-ordinator Peter Jirgens paid credit to the Green Army.

“Their help has been fantastic,” he said.

“At times we have had up to eight young volunteers here doing the work.”

The mangroves have been propagated at Riverwatch’s nursery at the Nowra Golf Club, are then taken and planted in areas along the river threatened by erosion.

A fence, featuring sandbags, is placed on the water side of the seedlings to ensure they are safe from both wave motion from passing boats and also other plants.

“We have to be careful when we plant the trees.  We have to protect them,” Mr Jirgens said.

“The ribbon grass (sea grasses within the river bed) can smother the young plants.

“We have to protect them for about three years.

“There is a lot of silt in the river. It is getting shallow which puts more pressure on the banks and leads to more erosion.”

Mr Jirgens estimated hundreds of thousands of tonnes of sand and banks were washed away in the August flood.

To make the work easier the Shoalhaven Riverwatch group has developed a product called the Shoalhaven Sand Sausage.

A metal framework has been constructed which can hold long lengths of fabric to make the equivalent of sand bags.

“Sand is shoveled into the fabric which is then sewn shut, making a large, continuous sand bag,” Mr Jirgens said.

“We can do up to 2.4m at a time instead of having to pack and lug sandbags.”

The ingenious idea is then used to protect the seedlings, placed between the new plants and the river’s waters and dissipates wave action.

For farmer John Bryce, who has already started bank stabilisation work along his property, the extra help has been a blessing.

“It’s great to be able to get this extra hands,” he said.

“I’ve lived here for 60 years and we have always been proactive in trying to maintain the river banks. We have revegetated bank areas and used rocks to try and stabilise other areas.

“In the past we used to have a low lying bank area between our high banks and the river. We had a 10-20 metre area .

“Over the years, despite our efforts, that has slowly been eroded. Now we are losing the high banks. In the last flood we lost huge slabs of banks.

“It’s great to be able to get the help from Riverwatch and from the Green Army. I’m not getting any younger and getting the work done is a huge job.

“They [the Green Army volunteers] have been so keen. They get in and get the work done with the Riverwatch volunteers - it’s just fantastic.”

The group will next tackle another section of the Shoalhaven River bank further downstream, at a major problem area near Jim Knapp’s property fronting Bolong Road.  Further work is also planned for a bank area near the Nowra Golf Course.