Friends of the Colo
- committed to eradicating willows from the Colo River
Friends of the Colo is a community based conservation group, formed initially to treat and eradicate willows from the Colo River within Wollemi National Park. When it was realised that the source of the willows was from outside the NP, FoC also became a Landcare group committed to eradicating willows everywhere within the Colo River catchment. This includes both public and privately owned land (with landowner permission). Our volunteers come from a wide range of interest groups and contribute a diverse range of skills in order to carry out this project.
The Colo River, free-flowing and pristine
The Colo River is one of the last remaining free-flowing streams in NSW and the last unpolluted river running into the Hawkesbury-Nepean River system. It is formed where the Wolgan and Capertee Rivers meet and flows for approximately 60 km through dramatic gorges and forests in the Wollemi National Park World Heritage and Wilderness Area. This is one of the largest wilderness areas in NSW and it remains relatively weed-free and untainted by human impact despite being only sixty km north-west of Sydney.
Canoeing the Colo during the first
Willows out of Wollemi trip (Photo: J. Cottrell).
Invasion of willows
In the 1990s this important and largely pristine wilderness reserve was discovered to have been heavily infested by invasive willows. Extensive surveying of tributaries of the Colo (the Capertee and Wolgan Rivers and Wollemi Creek) has established that these weeds are not spreading from areas upstream, as originally thought. Instead, these infestations have been caused by seed blown up the river from even larger galleries of black willows growing downstream of Wollemi National Park. There are also stands of crack or basket willows growing high up in the Wolgan River. These spread more slowly from broken stems and branches and work has commenced to control them also.
What’s wrong with willows?
Willows have many serious and damaging effects on the waterways which they infest. These include the development of large fibrous root masses which spread into the watercourse, trapping sediment and affecting the flow of water. In some cases the flow is lessened to such an extent that the river or stream is reduced to stagnant pools of water. When a flood does occur, the water is diverted by these root masses and erosion occurs. Of course, these changes have many deleterious effects on native fish, animals and vegetation. These willows spread and colonise rapidly and in huge numbers so their control is urgent. For these reasons they have been listed in the top twenty worst weeds in Australia.
Treating a willow tree trunk with
herbicide (Photo: J. Cottrell)
Our Program
Friends of the Colo has been active since 2000. In this time we have conducted several WOW (Willows out of Wollemi) trips and eradicated 99.9% of mature willows from within Wollemi NP. We are now working downstream of the NP, on mostly private land, to eradicate willows growing here. It is this work that will ultimately protect the national park from re-infestation. It also complements work being done elsewhere to control this pest. We continue to find young willows within the NP on our monitoring trips and until all mature willows in the catchment are located and treated the very real possibility of reinfestation remains. It is this monitoring and follow-up work which will guarantee the long term success of the program.
Access
Wollemi NP is a rugged area and much of the Colo River is bound by high cliffs and difficult to reach even for experienced bushwalkers and canoeists. Most of our trips into this area are multi-day activities suitable for those prepared and equipped for this kind of remote area activity. During our past five day WOW trips we have been transported to and from the river by helicopter and travel has been by canoe or inflatable raft. A grant from the Environmental Trust of NSW has enabled us to purchase inflatable rafts. Future helicopter use will depend on funding from various sources and possible assistance from NPWS. Shorter trips to specific areas can be done as bushwalks and most of the areas downstream of the NP are close to roads. This enables many people to join in our activities.
Other activities
As well as our WOW trips and willow eradication work FoC is working to control other significant weeds within Wollemi NP. These include tree of heaven and cape ivy.
We are active in promoting willows awareness within the local and regional communities and hope that this will encourage others to work to control this weed.
Friends of the Colo volunteers also carry out seed collecting for the propagation of locally native plant species at our volunteer nursery.
Volunteer nursery
Friends of the Colo have a volunteer nursery near the Glenbrook entrance to Blue Mountains NP. This nursery focuses on growing local provenance native plants by the longstem tubestock method. These are for planting along the Colo River in places where the banks have been largely cleared and for bush regeneration projects elsewhere. Species grown include blue gums, river oaks, sandpaper figs, tea trees, banksias and bottlebrushes.
If any one would like to help at the Nursery or just come for a visit contact Fred Wood on (02) 45796226.
Canoes in Colo Gorge (Photo: S. Cottrell)
New Members Welcome!
"Friends of the Colo" are always ready to welcome new members who share our concern for the long-term health of the Colo River and who are willing to contribute to the varied tasks this involves.
For further information, please contact: FriendsOfTheColo