This project is now in the monitoring phase with bi-annual monitoring trip of the river. We are aware there is still large numbers of Black willows in the Hawkesbury River which could re-infest the Grose and so are helping with control work on the Hawkesbury. 

We have an audio-visual presentation on the hawkesbury Nepean Placestories site for the project.

Click on this link to Google Maps to see the project map

The Grose River Black willow monitoring project commenced in November 2005 when 4 members of the willow warriors’ landcare group conducted a 12 kilometre monitoring trip by inflatable canoe between Faulconbridge point and Yarramundi. We did not expect to find many willows on this trip but instead in the 5 kilometres down to Burralow creek we found and treated about 40 black willows including one female which was in flower and producing viable seed. 

We had to stop treating at Burralow creek as we realised we were going to run out of daylight but in the in next 7 kilometres we found another 60 individual mature black willows and over 300 small black willows. The seedlings were growing in galleries on sandbars along the river.

Black Willow mainly spread by windblown seed and a single tree can produce tens of thousands of seeds each spring and which can be blown over 50 km from the source. So the willows we found were probably from seed blown up the river from black willows along the Hawkesbury River. These source willows had been treated earlier in the decade but no monitoring program had been set up after this project.

The majority of the Grose River is within the Blue Mountains World Heritage Area and the spread of black willows up the river would diminish these world heritage values. Downstream of the World Heritage Area the river is a great example of how many Australian rivers should look with hardwood logs locking in the bed and banks preventing erosion.
The treatment work commenced in January 2006, after obtaining consent from the landowners. Our willow warriors have complete the treatment, taking about 150 hours over 9 workdays. We poison the willows using roundup bioactive, and with our trusty tool kits, which include chisel and mallet, folding saw and secateurs, we either cut and paint, scrap and paint, or stem inject the willows.

The final activity involved a 3 day paddle from the Devils Wilderness to Yarramundi. The trip started with a seven hour bush bash carrying our inflatables, overnight packs and tools down to the river. We then paddled and climbed through a rugged gorge with portages under and over boulder jams. We only found 4 black willows on this trip and so believe we have found the upper reaches of the infestation
We completed the treatment phase of the project in 2008 and so we have added the river to our monitoring schedule. In March 2009 we undertook a monitoring paddle from Woods Reserve to Yarramundi treating 14 black willows some of which had grown into view and some were new seedlings which have come from black willows still being treated on the Hawkesbury.
We have also extended the project to treat black willows on the Hawkesbury River. But that’s another story.

We also use the paddle the river between Woods Reserve and Yarramundi for introductory, training and public awareness paddles for new members. New members are amazed at how beautiful the river is considering how close to Sydney it is.
We would like to acknowledge the support we received for this project from the Envirofund, Staff at Hawkesbury City Council and the Hawkesbury Nepean Catchment Management Authority and of course our volunteers.

I looks like we have the river happy.