Hunter River snags trees felled for expressway

09/11/2011:  Trees being cleared to make way for the Hunter Expressway will get a new lease of life as snags in the Hunter River, thanks to an innovative collaboration between Roads and Maritime Services (RMS) and NSW Department of Primary Industries (NSW DPI).

“In a generous gift back to the environment, RMS is supplying and transporting almost 1000 logs from trees cleared during construction of the Hunter Expressway,” said NSW DPI Conservation Action Unit manager, Kylie Russell.

“Logs from expressway works near Kurri Kurri will be used to restore and protect the riverine environment near Muswellbrook and Dalwood.
“This is equivalent to more than $64,000 worth of savings for the planned environmental projects.

“The logs will be used to construct Engineered Log Jams (ELJs) that will help stabilise eroding river banks and enhance fish habitat for native species such as Australian bass and mullet.

“Installing ELJs is expensive and requires many logs, so the donations from RMS will significantly increase the area that can be rehabilitated.

“Over the past three years, 34 engineered log jams have been installed in the Upper Hunter and more are planned for the coming year.”

Ms Russell said long term land clearing and snag removal in the upper Hunter River has significantly altered much of the river habitat, to the detriment of aquatic species and river stability.

“Restoring the river’s bank stability, in-stream habitat and riparian vegetation is now identified as a priority for natural resource management funding,” she said.

“Placing log jams strategically in streams helps direct flows away from eroding banks, create and maintain deep holes in the river bed, and provide a substrate for the growth of algae and insects.

“Large woody debris also plays an important role in dissipating the water’s energy and aiding in channel stability.

“Loss of this debris can accelerate the deepening and widening of the channel and disconnect the river channel from the surrounding riparian zone or floodplain.

“Logs also provide habitat and food sources for all levels of aquatic life, helping native fish and invertebrates find food, take shelter, hide from predators, grow and most importantly, to breed.”

The log jams are wedged into the bank and held in place by piles driven into the river bed. The structures are designed to be able to withstand large floods.

Courtesy of NSW Department of Primary Industries (NSW DPI)