Colo Catchment Invasive Willow Control PDF Print E-mail

This project started out controlling black willows in the Wollemi National Park and then expanded to control black willows in the whole of the colo catchment. The Black Willows cocntrol project is now in a monitoring phase with a bi-annual sweep of the catchment and has also expanded to treat other invasive willows, primarily crask willows in the upper catchment

 

Friends of Colo - History

 

The Colo River has held a fascination for people since the early days of settlement. There are countless stories of settlers, cattlemen, railway surveyors and adventurers exploring the river over the years. Before that, Aboriginal people travelled the Colo country extensively and appear to have held it in some reverence.

 

In the 1970s a group of bushwalkers came together and formed the Colo Committee. Their aim was to turn the area into a national park and wilderness area, thereby protecting it from the ravages of army operations and proposed dams and mines. The campaign, supported by a number of high profile citizens including Dick Smith, resulted in the 1979 gazettal of the Wollemi National Park. Most of the Park was included in the Wollemi Wilderness in 1999.

 

The National Parks and Wildlife Service and a variety of individuals and organisations who value the natural state of the area strive to keep it that way.

 

In the 1998 Graham Ravenswood, a bushwalker with Springwood Bushwalking Club, was enjoying a summer trip down the Colo River gorge floating on a lilo airbed. A professional bush regenerator, Graham was horrified to find extensive galleries of invasive willows downstream from Canoe Creek. He mapped their location and contacted the NPWS.  

Acting on Graham’s information, in 1999 Ian Turner, the ranger for the area, organised a party of six staff and volunteers, including experienced canoeists, to be dropped into the remote gorge by helicopter. They confirmed that the river was indeed suffering from willow invasion, but concluded that it might be possible to tackle it with the help of volunteers.

 

In April 2000 twenty five people including volunteers and NPWS staff, with plastic canoes, were dropped into three points on the river by helicopter. The aim of the exercise, organised by Ranger Vanessa Richardson, was to spend five days on the river, treating willows with glyphosate on the way. The most upstream party would cover about 60 kilometres in their journey down to Upper Colo. The Willows out of Wollemi (WOW) program was born.

 

During the exercise it rained on the catchment. The river rose by almost two metres, making the rapids dangerous, although the less experienced paddlers did not fully appreciate the dangers. Happily, no-one was injured. However, one canoe and some gear were lost. The flood also limited the opportunity for willow treatment.

 

Nonetheless, the exercise achieved fame—being featured on the ABC’s ‘7.30 Report’— and the cause gained profile and momentum. Some of the participants expressed interest in a proposal by Vanessa Richardson that a volunteer organisation be formed to support the project.

And so, on 5 June 2000, a meeting was held and the Friends of the Colo formed. The first committee members were Andy Macqueen (President), Michael Hensen (Vice President), Jeff Cottrell (Treasurer) and Secretary (Alan Lane). (At the time of writing, in 2007, Jeff remains the FoC Treasurer, while the President’s chair is occupied by Carol Isaacs, who succeeded Andy in 2002.) Vanessa Richardson provided enthusiastic support and the all-important liaison with NPWS, a task later inherited by Ranger Keirilee James. 

 

The new group set to work to plan future programs and apply for the grants which would pay for them. It was quickly found that each committee member had his or her own particular skills to contribute—something that had a major bearing on the final success of the group. Carol was a qualified bush regenerator, Andy knew the Colo well as a bushwalker and historian, Jeff was a very experienced paddler and was good with accounts, while committee members Fred Wood and Richard McGoogan could turn their practical minds to anything. Another member, Tony Rodd, was very knowledgeable botanist. Anthony Dunk developed and hosted a website for the FoC, and continues to update it over the years with photographs and FoC newsletters.

 

Fred and Richard started a nursery to grow plants that could be used for river bank rehabilitation along the Colo. They knew little about native plants at first, but they picked up the required knowledge from reading, and from field work with Tony Rodd. The nursery was located in the National Park at Glenbrook, with the cooperation of NPWS staff. Monthly working bees have been held there ever since, as the nursery continued to be a crucial part of FoC’s operations in spite of severe setbacks. In 2002 the nursery was destroyed by bushfire, while on other occasions it suffered drought, lightning strike and equipment failure, but Fred and his team were never deterred and the operation always recovered. At one stage a grant of $4000 from the Snowy Mountains Engineering Corporation Foundation provided vital assistance.

The nursery provided propagated seedlings not only for FoCs own operations on the river, but for various organisations that sought plants appropriate for regeneration projects. This yielded a source of funds for FoC’s ongoing operations. Seeds were collected for the nursery from the Colo area, and other places where clients had an interest.

 

Fred also studied the ‘long-stem planting’ method for riverbank stabilisation, and grew long-stem plants for use by FoC and others.

By January 2001 membership of the group exceeded 60 people. Active members included all the above mentioned, as well as Ian and Lyn Partridge who have remained active ever since.

 

Activities were planned to survey and treat willows along different parts of the river. In December 2000 two members, with a party from Springwood Bushwalking Club, travelled a remote upstream section of the river on lilo airbeds, surveying and treating willows on the way. In the same month, a trial WOW was conducted on a section of the river to see whether inflatable rafts would offer a better option than canoes: it was found that they did.

 

Meanwhile, training programs were developed in willow-treating and remote area skills, while the facilities of the Penrith Whitewater Stadium provided its facilities for whitewater awareness training.

 

In February 2001 FoC received the wonderful news that its Environmental Trust application for a three-year grant of $84,695 had been successful. The primary purposes of the grant were to eradicate the estimated 5000 willows from the 60 kilometres of the Colo River within the National Park, as well as to survey and treat willows and other weeds elsewhere in the catchment.

 

The grant enabled the second helicopter-assisted WOW expedition to proceed in April 2001, utilising inflatable rafts instead of the plastic canoes which had been deemed unsuitable for the more rugged parts of the river. Valuable assistance was provided by Jack Hodge of the Penrith Whitewater Stadium, who lent several rafts and provided expert guides to manage them. Bruce Baxter of Paddle Australia provided his own services as a guide and trainer. Jack and Bruce continued to support FoC in various ways over the years.

 

Although the second WOW, which involved 25 people, resulted in many willows killed, there was much left to be done. It was also noted that there were other weeds to be concerned about, including cape ivy and tree of heaven. Accounts of the WOW were presented, among other things, in FoC’s first newsletter, in June 2001. Prepared for the primary purpose of raising community awareness in the willow problem, the newsletter was put together by Simone Cottrell. The June 2007 edition of the newsletter will be the ninth, with the more recent editions having been prepared by Lyn Partridge.

 

The third WOW expedition took place in September 2001. A journalist and photographer from Australian Geographic joined the party, and their article was later published in the magazine’s edition of April-June 2003. This WOW resulted in the ‘primary knockdown’ of all the willows within the National Park, though it was recognised that willow seedlings would be springing up for years to come. A downside of this WOW was that the river level was very low, so it was very arduous dragging rafts through the rapids. This was found to be a continuing issue over the years.

 

By the fourth WOW, in April 2002, FoC had well-honed its skills not only in killing willows but in safely and efficiently managing what amounted to a challenging program on the river. It was observed that a kill-rate of around 98%  of willows was being achieved: most of the willows being treated were those that had previously been missed, or emerged as new seedlings, rather than trees which had been unsuccessfully treated on previous occasions.

 

In 2001 and 2002, FoC paid attention to the serious infestations of poplar, lantana, cape ivy and other weeds at Colo Meroo, at the downstream end of the National Park. The site was used as a base for treating not only those weeds, but also nearby willows. Quite a lot was achieved over a number of weekends, but a dispute developed concerning vehicular access to the site through neighbouring properties, and that facet of FoCs work had to be abandoned.

 

Meanwhile, there had been a new revelation. A party of NPWS staff and FoC members had completed a multi-day bushwalk to survey the Wolgan and Capertee Rivers, which feed into the Colo. Few willows were found, and no black willows—the most common species found on the Colo and the species of most concern. As a result of this, and the findings of the April 2001 WOW, it was concluded that the remote infestations of black willow on the Colo were not derived from plant material moving downstream from the catchment, but from seed blown from the extensive infestations in the settled parts of the river downstream.

 

This meant that in order to manage the willows within the National Park, it would be necessary for FoC to also turn its attention to willows along the river downstream, through the private lands. The willows there would be much easier for the group to access, but from the legal viewpoint it would be much more complicated to organise the work because many parties had an interest in that part of the river. Nevertheless, the group decided to become incorporated and to start dialogues with the Hawkesbury Council, NSW Government agencies, and private landholders.

 

FoC became an incorporated association in November 2001. Its stated objective was ‘to facilitate the conservation of Bushland in the Colo river catchment and its environs’, and its principle activities were the eradication of and prevention of invasion by weed species, and the re-establishment of native species.

 

After various surveys and a great deal of paperwork, work commenced on the ‘downstream’ willows in 2003, concurrently with the ongoing work in the National Park. Progress was slow at first as some land-holders regarded the group and its aims with suspicion. However, as time went on, persistent community awareness activities by FoC, and determined lobbying and networking by stalwart FoC treasurer Jeff Cottrell—assisted by supportive community members and Government agencies—paid off. One by one nearly all the landholders from Upper Colo to the Hawkesbury agreed to having the willows on their stretch of the river treated.

 

The fifth WOW took place back up in the gorge in April-May 2003, after a delay of several months brought about by a major bushfire. With virtually all mature willows in the National Park having been eradicated, the emphasis shifted towards careful survey and monitoring of emergent willows, and also the survey and treatment of other weeds—particularly tree of heaven and cape ivy.

 

About the same time, several members embarked on an arduous foot expedition along Wollemi Creek and tributaries. Only two willows were found.

 

In view of the consideration that helicopter support would not always be available for FoC operations, two heavy duty inflatable canoes were purchased to be used as alternatives to the rafts. Their advantage was that they might be carried in to remote parts of the river, albeit with difficulty, whereas the rafts were too heavy. They have subsequently been used extensively, though it has been found that the various craft all have their advantages and disadvantages in different conditions.

 

By April 2004, when the first Environmental Trust grant concluded, FoC was able to report not only that it’s immediate objectives within the National park had been met, but that nearly all mature willows from the Park down to the Upper Colo bridge had been dealt with. That meant that a river length of some 80 kilometres had been treated, not counting the work on the tributaries of the Colo.

 

Later that year FoC decided to apply for a second three-year Environmental Trust grant, to pay for helicopter-supported WOWs in 2005 and 2007, and various other expenses. A grant of $39,700 was awarded in February 2005. The 2005 WOW went ahead in March, with two parties being inserted into the gorge. Apart from a few willows, a variety of weeds were treated, including a cape ivy patch at the very remote Girribung Creek. The WOW planned for April 2007 was, however, cancelled due to the very low flow in the river—raising the question as to whether future work on the river, which requires less treating equipment than in the earlier times, might be better conducted by bushwalkers using lilo airbeds as transport.

 

By late 2006 FoC primary treatment of willows was completed along the rest of the Colo River, all the way down to the Hawkesbury River. On 2 December 2006 there was great fanfare when what was thought to be the last mature willow on the whole Colo River was treated—though subsequently other trees were discovered hidden away in various coves and branch creeks.

 

It was estimated that the group had removed 17,000 mature willows and seedlings from the Colo River system. But there still remained a few willows in the catchments of the Wolgan and Capertee Rivers, where local land management issues were delaying work. Also, many willows were still flourishing on a natural feature near Upper Colo known as Gospers Lagoon. Willows had been successfully eradicated from other lagoons in the area as early as 2003, but Gospers Lagoon was proving intransigent: floating rafts of mud and vegetation meant that access to the willows was difficult and unpleasant. However, it is essential that it be undertaken if reinfestation of the whole river is to be avoided. Work continues on the lagoon in 2007.

 

Meanwhile, FoC has maintained efforts to control some other weeds on the Colo, in particular cape ivy at Mount Townsend Bend, Boorai Creek and Girribung Creek, and tree of heaven at Tootie Creek and Pinchgut Creek. These places have been accessed on foot, often in conjunction with members of Springwood Bushwalking Club. The Mount Townsend Bend site in particular has proved a major undertaking, with ten weekend treatment activities having been conducted there since 2002. Despite several setbacks—including a bushfire which prevented access for a time and provided an opportunity for the weed to flourish—a large cape ivy infestation has been greatly reduced in size and intensity, reducing the risk of new infestations spreading further up into the National Park.

 

The more dedicated bushwalkers in FoC have conducted a variety of multi-day trips in the more remote parts of the Colo and its tributaries. These trips, which have tackled isolated emergent willows and other weeds, have usually been with members of Springwood Bushwalking Club. Others have been undertaken with members of the [Macmasters Beach mob].

 

As part of its aim to raise the profile of its anti-willow activities, FoC has also been active well away from the river too. Since 2004, three weekends have been spent at Putty, where members have assisted in a community program to control privet on farming land.

The FoC has also been associated with anti-willow efforts beyond the Colo. Several members have contributed their experience to programs on the Goulburn, Turon and Kowmung Rivers, while some have formed another group, the Willow Warriors Inc, which aims to tackle willows on wild rivers elsewhere in the state.

 

All in all, in the seven years since its inception in 2000, FoC has conducted some 150 activities involving around 15,000 volunteer hours. Nearly 100 volunteers have participated, though most of the work has been undertaken by about 20 longer-term members, and more particularly by about ten core members, most of whom have also served on the committee.

 

All this has not been entirely without its rewards. Apart from the personal satisfaction and camaraderie arising from doing a job well, there has been formal recognition. In 2003 the FoC was rewarded for its achievements by winning the inaugural ‘Weedbusters Award for Excellence’ for the state of NSW. The nomination had been made by Trish Chadwick, from the Department of Infrastructure, Planning and Natural Resources, who had been engaged with the group in its efforts to gain approvals for willow removals on the private lands. This award was presented at the biennial State Weeds Conference Dinner. About the same time, Fred Wood received a bronze Landcare Legends award at the Fourth NSW National Landcare and Catchment Awards Dinner in Bateman’s Bay: Fred had been active not only with FoC, but also on other conservation projects in the Hawkesbury area.

 

FoCs efforts have been used as a case study in willow control by the NSW Department of Primary Industries and Department of Environment and the National Willows Taskforce and Weeds CRC.

 

 
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