ISSUE 10, 1998 TREAM ANK stability: why, what, where and how? Why is streambank stability important? We are all familiar with what can happen when land is overcleared, stock grazed without control along streams, gravel extracted from streambeds and watercourses straightened to make naviga- tion easier. Whilst streams and rivers ‘naturally’ experience erosion and other channel changes, the impact of activities like those listed above has, since European settlement, accelerated these processes to often unacceptable levels. Streambank stability is important because a physically unstable stream can cause many problems. Without stable streambanks, infra- structure such as buildings and bridges can be threatened, valuable and productive land lost, stock injured and important habitat lost for native plants and animals. These financial and environmental costs make streambank stability one of the most important management issues facing landowners and catch- ment communities across Australia today. continued page 3 b S RP RP ia NEWSLETTER OF LWRRDC’S RIPARIAN LANDS R&D PROGRAM
Transcript
ISSUE 10, 1998
TREAM ANKstability: why, what,where andhow?
Why is streambank stability important?We are all familiar with what can happen whenland is overcleared, stock grazed without controlalong streams, gravel extracted from streambedsand watercourses straightened to make naviga-tion easier.
Whilst streams and rivers ‘naturally’ experienceerosion and other channel changes, the impact of activities like those listed above has, sinceEuropean settlement, accelerated these processesto often unacceptable levels.
Streambank stability is important because aphysically unstable stream can cause manyproblems. Without stable streambanks, infra-structure such as buildings and bridges can bethreatened, valuable and productive land lost,stock injured and important habitat lost for nativeplants and animals.
These financial and environmental costs makestreambank stability one of the most importantmanagement issues facing landowners and catch-ment communities across Australia today.
continued page 3
bSRPR Pi aN E W S L E T T E R O F L W R R D C ’ S R I P A R I A N L A N D S R & D P R O G R A M
CASE STUDY INFORMATION2 THEME GETTING A GRIP IT’S A WRAP
This publication is managed by the Land and Water ResourcesResearch and DevelopmentCorporation (LWRRDC), GPOBox 2182, Canberra ACT 2601.
LWRRDC’s mission is to providenational leadership in utilisingR&D to improve the long-termproductive capacity, sustainableuse, management and conserva-tion of Australia’s land, water and vegetation resources. The Corporation will establishdirected, integrated and focusedprograms where there is clearjustification for additional publicfunding to expand or enhance the contribution of R&D to sustainable management of natural resources.
LWRRDC’s Home Page is:www.lwrrdc.gov.au
Issue 10, 1998RipRap is published four times a year. Contributions andcomments are welcomed and should be addressed to the Editing Team.
Haughton River Mill Farm 5Local government focus 7Getting a Grip: Notes from the field 8Case study 2:
‘Elverton’ and ‘Old Whisloca’ 9It’s a Wrap: News from around Australia 12
Hello! and welcome to the tenth edition of RipRap. My name is SiwanLovett and I am the Program Coordinator for the Riparian Lands Researchand Development Program.
With my appointment as the new program coordinator, it seemed anappropriate time for RipRap to take on a new look. Each edition of RipRapwill now be focused around a particular management issue, and will aimto provide material that is practical, relevant and informative to a widerange of groups and organisations.
The newsletter will maintain the case study segments so that we cansee what is happening in the ‘real world’ of riparian management, as wellas providing information about new research findings, upcoming eventsand a whole lot more…
This edition of RipRap is dealing with the difficult management issueof streambank stability. Potential issues for future RipRaps include: how to define the riparian zone for management purposes, integrating riparianmanagement into farm planning, and how to work out what the criticalriparian issues are in your catchment. We welcome your suggestions onfuture themes.
I hope you find the newsletter useful, and look forward to receivingyour comments on the revised format. Happy reading!!
Siwan
CON entst
RIP rian lands:aWHERE LAND AND WATER MEET
3INFORMATIONCASE STUDY GETTING A GRIP IT’S A WRAPTHEME
TREAM ANK stability continued from page 1
Interrelation of fluvial bank erosion and mass movement.
Mass movement. Photo by Leonard Sands
bThese are:1. Subaerial erosion — this occurs when the bank is exposed to the weather
and is subject to a variety of processes eg. rainsplash, stock trampling.2. Scour — the direct removal of bank material by flowing water.3. Slumping — a mass movement that occurs when bank material slips
or falls into the stream.Another process that contributes to streambank instability is channelincision.This occurs following activities such as channel straightening, flowregulation and sand and gravel extraction, and can cause large amounts ofmaterial to be eroded and deposited downstream.
The immediate impact of the removal of this material is to make thechannel deeper, whilst the downstream effect is a build up of sediment thatcan sometimes reduce light and smother aquatic habitats.
All these processes take place along the length of our streams andrivers. The extent to which they affect streambank stability is, however,dependent upon the composition of the bank, flow regime, channel sizeand level of human disturbance.
What can be done?Any stream system that experiences accelerated erosion processes willhave little prospect of long-term stability unless management strategies aredeveloped and then actively implemented.
Increasingly, decisions about how to deal with the problems of stream-bank instability are being made following input from many different disci-plines, for example: ecology, engineering, hydrology and geomorphology.This is because there is growing recognition that management strategiescombining a number of different techniques are more likely to result inlong-term stream stability and ecological sustainability.
Revegetation: the environmentally friendly optionStreambank erosion is strongly influenced by the density and type ofriparian vegetation: in most cases riparian vegetation helps banks to resisterosive forces. Revegetating unstable streambanks is, therefore, a techniquethat can provide relatively cheap long-term stability, as well as providing ahost of other benefits for native riparian plants and animals.
Prior to revegetating, it is important to understand why streambankerosion occurred in the first place.Without this understanding you cannotbe confident that the revegetation strategies you select will work.Conducting a river reach survey, or seeking professional advice is animportant step in the planning process. Without a planning process workcould be undertaken that may not be appropriate or successful. Forexample, research has demonstrated, that revegetating the toe of the bankshould often be the first step in implementing stabilisation strategies.
Although revegetation is a positive option for the environment, in somecases it is not enough to address streambank stability problems. In theseinstances it may be appropriate to use complementary engineeringsolutions. continued over
Many processes contribute to streambank instability. The important point to remember,however, is that these processes are oftentriggered by particular land and water manage-ment practices. For example, activities such as theover-clearing of land, allowing uncontrolled stockgrazing along watercourses, and the straighteningof channels, disturb the equilibrium that existsbetween the flow regime and channel. Disturbingthis equilibrium catalyses processes such aserosion and channel widening, which are bothkey causes of streambank instability.
Erosion occurs as a result of interactionsbetween the streambank, weather and flow.Thereare three broad categories of bank erosionprocesses.
What are the processes that cause streambank instability?
S
INFORMATION
Further informationJanice Oliver, Communication OfficerNational Land and Water Resources AuditTel: (02) 6257 9517, Fax: (02) 6257 9518E-mail: [email protected]
AU IT announce entThe National Land and Water Resources Audit WebSite was launched inJuly.While you’re next surfing, check it out at http://www.nlwra.gov.au.TheAudit Strategic Plan was recently released for comment.Your feedback onthe Plan is welcome. Feedback can be returned ‘reply paid’ using thefeedback form in the back of the printed version of the Strategic Plan or,by e-mail to [email protected]
Also available are the Audit brochure and a series of ‘Fast Facts’which give an overview and progress of the Audit. All of these areavailable on the website in the publications area or paper copies canbe requested.
To keep up-to-date on the progress of the Audit you can also joinour electronic mailing list — ‘Audit Info’. Each month regularpostings will be made on the progress of the Audit and the releaseof new publications. Frequently asked questions about the Audit willalso be answered.
To join the Audit Info electronic mailing list, send an e-mailmessage to: [email protected]. Leave the subject lineblank. In the message body type: subscribe auditinfo <your e-mailaddress>. For example, if Jane Doe was joining the list, she would typein the message body: subscribe auditinfo Jane Doe
Engineering approaches: when needs must
When erosion is threatening a high value asset (such as a bridge orbuilding), or is occurring in high energy situations (such as gullies) withhigh, steep streambanks, vegetation may not provide sufficient resistanceto protect the asset or control erosion.
In these cases it may be necessary to combine vegetation andengineering approaches. Many structures can be used to stabilise stream-banks, for example the pilegroynes pictured below.
As with revegetation, itis important to understandthe cause of the stream-bank stability problem priorto establishing any new engineeringstructures.
How do I find out more?Read on! There are case studies, research findingsand more information about streambank stabilityin the following pages…
ReferencesKapitzke, I. et al., 1998. ‘Stream stabilisation for Rehabilitation in North-East
Stability’. LWRRDC. (Available free from LWRRDC.)Raine, A. and Gardiner, J., 1995. ‘Rivercare for Ecologically Sustainable
Management of Rivers and Riparian Vegetation’. Occasional Paper No. 03/95 LWRRDC.
These publications are available from the DPIE Shopfront —Edmund Barton Building, Core 2 Entrance (off Blackall Street)Barton 2601. Tel: 1800 020 157.
4 THEME CASE STUDY GETTING A GRIP IT’S A WRAP
TREAM ANK stabilityS b
d m
Below: Groynes on the Musgrave River, Qld. Above: Pile groynes.
Photo
by R
ichard
Pears
on
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X-Sect 1
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Distance (m)
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Distance (m)
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(m) RL 5.1 9/1/96
RL 5.1 9/1/96
RL 5.1 9/1/96
Rock groyne (typical)
RL 5.0RL 5.5
Source: Water Resources Ayr 12/93Note: Cross sections looking upstream
INFORMATIONCASE STUDY GETTING A GRIP IT’S A WRAPTHEME
CASE STUDY
EnvironmentThe Haughton River basin is located entirely inthe dry tropics zone and, therefore, has lowerannual rainfall, runoff volumes and runoffdepths than wet tropics streams. Nevertheless,the river is subject to periodic severe floodingfrom tropical cyclones. The Haughton River has distinct downstream-decreasing channelcapacity on the floodplain, and experiencesmajor overbank flows that lead to overbankerosion and threats of channel avulsion. Most ofthe native woodland vegetation on the HaughtonRiver floodplain has been cleared for sugarcaneproduction, leaving thin broken riparian corri-dors.The river has a sandy bed and non-cohesivebank materials that are susceptible to fluvialerosion.
Case study siteThe Haughton River Mill Farm site is located onthe Haughton River adjacent to the township ofGiru, approximately 15 kilometres upstream ofthe river mouth. The site is located on a slightbend in the river, where erosion on the outsideof the bend has threatened channel avulsion anddamage to the adjoining agricultural land, theInvicta sugar mill and Giru township. The riverbank receded up to 20 metres in the 40 yearperiod prior to 1991. In 1991, a sequence ofmajor floods caused further erosion of approxi-mately 15 metres (see below).
Strategies and treatmentsRock groynes were constructed at the sitefollowing the 1991 floods, with the objective ofprotecting the bend, limiting further loss ofagricultural land and reducing the likelihood ofchannel avulsion that may result from bankerosion and lowering of bank level. Four rockgroynes were installed, angled downstream to thebank, with a tapered top profile that sloped awayfrom the bank. The groynes were adopted inpreference to the rock revetment option, whichwas more expensive, and more likely to requiresupplementary rock fill at the toe after floodevents. The groynes were also preferred to therevetment as they reclaimed the original streamalignment, thus minimising the likelihood ofchannel change downstream. Furthermore, theyretained the riparian land/ water interface, thusproviding for re-establishment of a healthyriparian zone.
HAUGH ONRiver Mill Farm
1t
Eroded Stream Bank prior toconstruction of rock groynes.
Photo by Ross Kapitzke Treatment cross-sections.
GETTING A GRIPCASE STUDY INFORMATIONIT’S A WRAP
Definitions~ Channel avulsion: occurs when there is an
abrupt change in stream course and conse-quent abandonment of the pre-existingchannel.
~ Rock/pile groyne: these are structures that(are usually impermeable) project from thestreambank. They are designed to increaseflow resistance and direct streamflow awayfrom the bank through a preferred channelalignment.
~ Rock revetment: this structure provides‘armour’ for the streambank against fluvialerosion, as well as providing stabilisationagainst slumping.
~ Bathymetric surveys: surveys of depth andcurrent conducted under water.
Contributing organisationsHaughton River Improvement Trust; McIntyre& Associates Pty Ltd; Department of PrimaryIndustries (Department of Natural Resources)and James Cook University.
For more informationRoss Kapitzke, School of Engineering, James Cook University, Townsville QLD 4810 Tel: (07) 4781 4810, Fax: (07) 4775 1184 E-mail: [email protected]
Report’, report prepared for Haughton River Improvement Trust. Kapitzke, I.R. and Sands, L.B. 1996. ‘Site Monitoring Report — Physical
Component’, Research Report No. 5, prepared by James Cook Universityfor the Land and Water Resources Research and Development Corporation.
Kapitzke et al. 1998. ‘Stream Stabilisation for Rehabilitation in North-EastQueensland’. LWRRDC.
6
Monitoring and performanceRock groynes are impermeable structures, that tend to concentrate flowsat the toe of the structure and cause turbulence downstream due toovertopping. They may also affect the downstream flow conditions andcause bank erosion immediately adjacent to the structures. Flow velocitiesand flow patterns are, therefore, important for design of the rock fills aswell as in the prediction of sedimentation impacts and alterations toinstream habitat between the structures.
Since 1993, a monitoring program has been in place that has focussedon pre-and post-flood bathymetric surveys, the measurement of flow veloc-ities and observation of flow patterns around the groynes. Minor floods inthe Haughton River in February 1994 and January 1996, and a more severeevent in March 1997, caused no appreciable damage to the site.
SummaryThe groynes are more suited to the site than the rock revetment option asthey are less expensive and have successfully retained the land/water inter-face. Revegetation of the site is now required to rehabilitate the riparian andinstream habitat. Although only limited information has so far beenobtained, the monitoring data has assisted in an understanding of floodstreamflow velocities within the groyne field. The success of the rock inwithstanding the high flow velocities at the toe of the structure, and theeffect of the groynes on downstream erosion are of ongoing interest.
HAUGH ON River Mill Farmt
This case study has been taken from the new Stream Stabilisation for Rehabilitation inNorth-East Queensland Manual. This manual identifies some of the primary problems andcauses of river degradation, as well as treatments and management techniques. It recog-nises that the sustainable use of streams depends on a range of factors such as geology,hydrology, climate, ecology, sociology, culture and economics. If you would like a copy pleasecontact the Department of Primary Industries and Energy Shopfront on 1800 020 157(cost $25.00).
Rock groynes. Photo by Mark Crees.
THEME
7INFORMATION
As part of the NHT Bushcare program,Environment Australia has provided funding for aNational Local Government Bushcare Facilitator.Rob Thorman, who is based at LWRRDC inCanberra, has been contracted to undertake thisrole. The Bushcare program provides assistancefor local governments to become more involved in vegetation management. This includes directgrants, technical support and advice. There is anetwork of regional facilitators to help withregional planning and project development, and a Bushcare support network, administered byGreening Australia and other groups, that
provides technical assistance and training.Local government has a particular interest in
riparian zone management, as they are involvedin floodplain management, erosion control andthe protection of infrastructure. Local govern-ment have traditionally used engineeringsolutions. However, there is a growing awarenessthat revegetation in many cases is not only moreenvironmentally friendly, but also a more cost-effective solution.
Rob is compiling a data base of councils thatare adopting innovative approaches to vegetationmanagement. If you know of good examplesplease contact Rob.
My new role involves coordinating a team to deliver botanical and GISsupport to community groups and local and state government stakeholdershere in Tasmania. This program is funded through the Natural HeritageTrust Bushcare and Rivercare programs and aims to improve the mannerin which we manage our native vegetation.
I would like to thank all those involved in the Riparian Program fortheir support over the last three years, as well as all those readers of RipRapwho have contributed articles and positive feedback about the newsletter.As the tenth issue hits the streets, I can be happy in the knowledge thatpeople have gained something positive from the articles we have published.In particular, I would like to thank Sally Berridge who edited all thenewsletters I have been involved with, and did a great job.
Finally, I would like to wish Siwan all the best in her new role in theRiparian Lands R&D Program. Siwan has a big challenge ahead of her,but I am sure she will make a great success of it. All the best to everyonefor the future. Michael Askey-Doran
THEME CASE STUDY GETTING A GRIP IT’S A WRAP
Further information
Rob Thorman, Local Government Bushcare FacilitatorGPO Box 2182, Canberra ACT 2601Tel: (02) 6257 3379, Fax: (02) 6257 3420E-mail: [email protected]
Editor’s noteLocal government is an important natural resources manager.In recognition of this, RipRap now has a column specificallyallocated for local government news. If you would like the workof your local government agency featured in RipRap please letme know! Siwan
TI E to move on: Michael Askey-Doran takes up a new role
After three years involvement withLWRRDC’s Riparian Lands R&DProgram the time has come to moveto new fields. My time with theprogram has been very beneficial,and I have had a great opportu-nity to broaden my knowledge inthe area of river management andecology.
m
Councils are able to influence riparian vegetationmanagement through:~ strategic planning and zoning;~ provision of incentives, such as rate rebates, to encourage private
land holders to manage riparian vegetation on private property;~ management of Council and Crown reserves;~ management of the impacts of infrastructure development such
as water and sewerage provision; and~ provision of direct assistance to community landcare groups,
through the use of machinery, access to council nurseries andadministrative support.
OCAL overnment focus Introducing the new Bushcare FacilitatorL g
Rob Thorman
IT’S A WRAPCASE STUDY INFORMATION
The success of any riparian or channel restoration relies on sustainable channel alignment and the stability of the channel bed and toe.Without these, you aretreating the symptom rather thanthe cause.Variations to a river bedlevel are often so gradual that they are not easily noticed by the local community.Revegetation of the riparian area and restoration of the aquatic and terrestrial ecology depends on sustainable channel alignment and a stable channel bed and toe.
Protection of tributaries from stockMost publicity about stream bank degradationand its associated impacts focuses on mainstreams. However, at least as much interactionbetween the catchment and the stream occursalong the tributaries.
Although it may not be feasible to fence alltributaries, simple temporary electric fences canbe useful along smaller ones. The best overallstrategy is to provide an alternative water supplyand shelter away from all streams, includingtributaries, thus reducing the time stock spend in these fragile zones. Strategic water supply sitesand shelter well away from streams also paydividends through more even grazing pressure,improved pasture use and drought resistance.
For moreinformation
Ian BellDepartment of PrimaryIndustries and FisheriesPO Box 46, Kings Meadows TAS 7249Tel: (03) 6336 5378Fax: (03) 6336 5365
8 THEME GETTING A GRIP
Getting a RP
Background showing recovery of banks in a small tributary following fencing.
Stock access to small tributariesis a common problem.Photos by Ian Bell.
G i Getting a grip on new research findings and issues is important. This segment of RipRap provides short, sharp research notes that can be practically appliedin day-to-day natural resources management.
For moreinformation
Peter Wem, details page 16.
The secret to successful riparian or channel restoration
“Ecoman and Dr Earth Getting a Grip” by Morgan Kurrajong
and Ed Radclife
9INFORMATIONCASE STUDY GETTING A GRIP IT’S A WRAPTHEME
Apart from damage being done to thefarmland, this erosion had a significant impact ondownstream users, especially with the North Eskbeing a major water supply for the City ofLaunceston. After six years of ‘red tape’ the RiverImprovement Scheme finally got under way.
Strategies and treatmentsIan Dickenson was the principal contractor forthe project works. In areas where erosion waslikely to occur, willows were cut off leaving thestumps to hold the banks. Willows that weregrowing across, or in the stream, were removedcompletely. In a few instances the river wasstraightened, but only where it was considered it would break through if left alone.
Large logs and stumps were used to stabilisethe banks, with care taken to ensure that floodingwould not wash them away. To minimise this risk, the logs and stumps were ‘knitted’ in. Theywere also back-filled with shingle and, in somecases, rock.
Environment‘Elverton’ and ‘Old Whisloca’ are mixed grazing,cropping and forestry properties totalling 2082hectares. The properties are about 400 metresabove sea level, with an average annual rainfall of850 millimetres.They are situated on either sideof the North Esk River, in the middle flood plainreaches of the catchment. Each property has aproportion of river alluvial soils grading back to slopes and foothills made up of sandy loamsand shales.
Case study detailsWhen ‘Elverton’ was purchased by Ian andRosemary Dickenson in 1969, it consisted of rundown pastures and native forests that wereheavily cut-over. Since then it has been devel-oped to significantly increase production,through the application of whole farm planningand farm forestry principles.With these changeshas come a vision for sustainable management.The addition of ‘Old Whisloca’ in 1989, resultedin continued pasture improvement and theimplementation of a cell grazing program.
Rehabilitating the riparian zone
In conjunction with the Rivers and Water SupplyCommission and other landholders, major riverrestoration works were undertaken along12 kilometres of the North Esk River in the1980s. A key feature of these works was theremoval of crack willow from the water-course.Congestion of the river by crack willow wascausing exacerbated flooding and diversions ofpeak flows, leading to extensive erosion anddamage to areas of the flood plain.
CASE STUDY 2
‘ELVER ON’ and ‘OLD WHI LOCA’
Managing the riparian zone within a total farm system
Clearing willows 1989.
Actively eroding bank.
Ian Dickenson
ts
GETTING A GRIPCASE STUDY INFORMATION
SummaryThe management decisions that have been takenby ‘Elverton’ have been based on the principlesof ecologically sustainable development, with thedevelopment of a whole farm plan that focuseson integrated resources management.This focushas resulted in the riparian zone becomingmanaged as an integral, yet different, part of thewhole farm system.
In recognition of the work that was under-taken by Elverton Pastoral Company Ltd, Ianand Rosemary Dickenson were awarded theTasmanian Landcare Award in 1997.
For more information about the work that Ianand other farmers have undertaken see page 11.
THEME IT’S A WRAP
Following this initial phase of willow clearing and bank stabilisation,the riparian zones are now being progressively fenced off in order to bettermanage stock access. As a result, water contamination and erosion is beingminimised.This is a major consideration, as the North Esk is an importantcatchment for Launceston’s water supply. About twenty bridges have beenconstructed in order to avoid driving stock and machinery through water-courses. The riparian zone and other forested areas are either not grazed,or are only grazed periodically.
Monitoring and performanceAn ongoing program of monitoring and maintenance is followed on bothproperties to ensure that the willow and bank stabilisation problems do notrecur.The willow stumps that were originally left are constantly trimmed,with the aim being to leave enough stumps to ensure bank stability, but notso many that trimming becomes too costly. Sheep are also used to controlregrowth.
A program of weed management is also in place, with an ongoing gorsereduction effort, and an annual ragwort ‘pull’. Around $1000 is spent eachyear on preventing fresh incursions of ragwort, which flows down fromhigher up in the catchment on flood waters. Willow infestations are alsobeing progressively eliminated from the watercourses, with the overall aimto have weed infestation down to 0.1% of the property by the year 2001.
10
LES ONto be learnt
Managing the riparian zone differently doesnot necessarily mean losing the use of thezone within agricultural enterprises. Theriparian zone can contribute to productivitygains. For example, research has shown thatbuilding up the riparian zone providesshelter for stock, improved water quality andreduced erosion, all of which benefit thelandholder. The lesson to be learnt is thatenvironmental and economic benefits arenot mutually exclusive.
Logs and stumps used to restabilise banks.
Willows regrowing 1998.
‘ELVER ON’ and ‘OLD WHI LOCA’t s
s
Photo
s in t
his ar
ticle
by Ia
n Dick
enso
n.
11INFORMATION
Rural Australia knows that sustainableagriculture is no longer an option.
NFF’s publication Hand in Hand:farming sustainably illustrates, through aseries of case studies, that economic andenvironmental sustainability go hand inhand. Sustainable agriculture meansimproving economic efficiency andproductivity, along with the equal needfor protection and enhancement ofenvironmental values. Today, environ-
mental concerns are an integral part ofevery decision that farmers make about what they do on their farms.
NFF has a long term commitment to making the Australian agricul-tural sector sustainable into the next century.This is why NFF was not onlya founding member of the National Landcare Program, but continues to be one of its strongest advocates and supporters.
The bottom line for farming is that it must be both profitable and environmentally sustainable. The two arenaturally complementary and neither can existwithout the other.
For more information, contactAnwen Lovett, National Farmers’ Federation, GPO Box E10, Queen Victoria Terrace, Barton ACT 2600 Tel: (02) 6273 3855, Fax: (02) 6273 2331
THEME CASE STUDY GETTING A GRIP IT’S A WRAP
WIL OWmanagement
PLAN FIRST: ACT SECONDThe following recommendations should beconsidered by any individual or groupplanning to address willow problems:1. Develop a long-term plan for willow
management that draws upon expertadvice. It may be that this plan has to besubmitted to a relevant governmentagency for authorisation prior to imple-mentation.
2. Ensure that your plan complies with therelevant legislative provisions in yourState or Territory (eg. in NSW approvalis required prior to removing vegetationwithin 20 metres of a waterway).
3. Gain expert advice that provides information about the impact on thewaterway and its banks of particularwillow management options. (It isimportant to remember that removingwillows can sometimes increase, ratherthan decrease, erosion problems.)
4. Consider replacing willows with moredesirable species, as well as fencing andstock-proofing rehabilitation areas.
5. Ensure that you plan for ongoingmonitoring and maintenance of willows,as their management requires longrather than short-term solutions.
ReferencesTrounce, B. and Cremer, K. 1995. ‘Willow Control’. CSIRO Division
of Forestry. Canberra (contact Robert Trounce, NSW Agriculture,Locked Bag 21, Orange NSW, 2800).
Cremer, K. ‘Willow Identification for River Management in Australia’.CSIRO Division of Forestry. Canberra (contact the author).
Australian Manual of Stream Restoration — Amanual to assist land and water managers, will beavailable in November 1998. This manual willprovide tools and techniques for dealing withproblems like willow — look out for more informa-tion in the next issue of RipRap.
l NFF boo letHand in Hand
For your free copyof Hand in Hand:farming sustainably,contact the NationalFarmers’ Federation.
k
S REAM corridorsAdaptive Management and DesignSecond International Conference on Natural Channel Systems1–5 March 1999. Sheraton Fallsview, Niagara Falls, Canada
For anyone interested in learning, sharing, promoting and integratingknowledge and experience in various aspects of river and stream systemsmanagement. Topics include:• National, regional and local strategies • Management issues• Innovations in stream corridor management • Design• Interactions and community involvement • Case studies• Research and development • Monitoring
CASE STUDY INFORMATIONTHEME GETTING A GRIP IT’S A WRAP
If you belong to a community group, theNational Rivercare Program, funded through theNatural Heritage Trust (NHT), can help yourepair your local creek, river or stream. Rivercarefunding is potentially available for a range ofactivities aimed at reversing or preventing degra-dation in riverine environments, includingriparian areas, river beds and banks. Examplescould include community groups fencing off astretch of river to exclude stock and improvevegetation, with consequent water qualitybenefits; as well as activities designed to improvein-stream habitat, manage erosion and stabiliseriver banks and beds.
The funding guidelines for the NationalRivercare Program are flexible. They aredesigned to allow most local problems to beaddressed within a set of broad principles. TheProgram encourages groups to tailor their activ-ities to particular issues or problems, thereby
recognising the value of local knowledge andexperience in developing practical solutions.In all cases, projects submitted for NationalRivercare Program funding will need to be clear about the problem they are addressing,how activities willtarget the causes of the problem, and thebenefits that willresult. Project propo-nents also need to takeaccount of other activ-ities that could effectthe success of theproject. The best way to do this is through acatchment plan which integrates land, water andvegetation management issues. Above all, it isimportant that projects are feasible, cost-effectiveand technically sound, including in an ecologicalsense.
As well as funding on-ground projects,Rivercare aims to raise community awarenessand monitoring through the WaterwatchAustralia Program, and to coordinate researchand development through the National RiverHealth Program.
A Natural Heritage Trust project applicationguide is produced each year to assist projectproponents develop an eligible application forpossible funding, including under the NationalRivercare Program. The guidelines for nextyear’s NHT round (1999–2000) are expected tobe released in September.
For furtherinformation
Anne Tarran, National Rivercare InitiativeDepartment of PrimaryIndustries and EnergyGPO Box 858, Canberra ACT 2601Tel: (02) 6272 4216, Fax: (02) 6272 4526E-mail:[email protected]
12
It’s a RAPwKeeping up to date with what is happening across Australia in the area of natural resourcesmanagement is vital. This section of RipRap provides States and Territories with the opportunityto ‘wrap up’ key activities, research and upcoming events.
FOCUS ON RIVERCARE
National Rivercare Program — tailoring projects to problems
The National Rivercare Program operatesoutside the Murray-Darling Basin. Aseparate program, Murray-Darling 2001,focuses on Basin areas. In 1997–98, the firstfull year of funding, the Commonwealthprovided just over $6 million for projectsassociated with “on-ground” or implemen-tation activities under Rivercare. Thisamount will almost triple in 1998–99 andincrease further in the last two years of theprogram.
LWRRDC has a number of publicationson ecologically sustainable management ofrivers and riparian vegetation that may beuseful in planning potential Rivercareprojects. State/Territory natural resourcemanagement agencies are another usefulsource of information and advice.
ommonwealth contributionC
13INFORMATION
The establishment of the Natural Heritage TrustFund in 1997 has led to an increased focus onriver management issues in Tasmania. Much ofthis attention has come from community groupssituated in rural regions, with close involvementby local and state government agencies. Willowmanagement and removal has been the drivingissue behind most Rivercare activities inTasmania, and with this type of activity is theneed to protect or rehabilitate the stream channel
THEME CASE STUDY GETTING A GRIP IT’S A WRAP
ivercare in asmaniaR TThe importance of planning
and revegetate cleared areas. Many groups arealso looking at fencing out stock from sections oftheir river to protect native vegetation andstreambanks from stock damage.
Those projects focusing on willows haveresulted in some significant on-ground worksand disturbance in the initial phase. The diffi-culty with these projects has been the need tobalance environmental issues such as aquatic andriparian ecology, water quality and channel
Cartoon by Morgan Kurrajong and Ed Radclife
CASE STUDY INFORMATION
stability, with the economic and time constraintsassociated with the use of large machinery inand around rivers. For many groups, the focushas been on willow removal and stabilisation ofthe channel, with the next phase of providinglong-term solutions through controlling stockaccess and revegetating cleared areas, paid lessattention. Whilst groups do appreciate theimportance of controlling stock and revegetatingalong rivers, it often becomes too difficult within the limited funding period to tackle large revegetation projects. Groups are nowbeing encouraged to develop new projects thatwould enable worksuch as revegetationand stock manage-ment to be carried out.
In order to increasethe opportunities forgood outcomes, groupscarrying out ongroundworks such as willowremoval and channelworks are required todevelop a RivercarePlan. Guidelines havebeen produced to helpgroups develop theirRivercare Plans. Theplans must detail thelong term vision whichthe groups have fortheir river, and set outhow they may achieveall, or part of, thisvision through theirworks. As part of theRivercare plan, the groups seek advice fromappropriate experts on riparian and aquaticecology, water quality, and engineering andhydrology. Recommendations are provided back to the groups and can be included in theRivercare Plan.
Rivercare plans contain information aboutthe activities a group seeks to undertake. Formany projects, these activities occur in twophases: initial on-ground works such as willowremoval, and in-stream works such asconstructing riffles; and a second phaseinvolving revegetation, stock control andongoing maintenance. The groups are requiredto clearly detail the methods they will use forwillow removal, including how much is to be
14 THEME GETTING A GRIP IT’S A WRAP
removed and over what period of time. It is alsoimportant that in-stream works are welldocumented, so that the nature of the works andtheir extent can be clearly understood by thoseassessing the project. In the second phase, prior-ities can be set for fencing and revegetatingareas of the river. Groups may also decide totarget areas that are most susceptible to erosionor affected by stock access. An importantcomponent of this second phase is the need toestablish a formal maintenance agreement, sothat the effectiveness of the riverworks does notdecline over time.
It is hoped that with a greater recognition of the need to provide technical support tocommunity groups Rivercare plans will result in good environmental outcomes, whilstmaintaining the productive nature of theadjacent land.
For further informationMichael Askey-Doran, National Parks and Wildlife ServiceGPO Box 44A, Hobart TAS 7001Tel: (03) 6233 6168, Fax: (03) 6233 4833E-mail: [email protected]
Rivercare in Tasmania
Field days are an important mechanism for providing information on Best Management Practices, Meander River, Tasmania.
Photo
by M
ichae
l Ask
ey-Do
ran.
15INFORMATIONTHEME CASE STUDY GETTING A GRIP IT’S A WRAP
During May 1998, the Water and RiversCommission held a very successful week-longRiver Restoration workshop at Fairbridge,Pinjarra. The workshop was a training programfor people from community catchment groups,local government and Landcare DistrictCommittees. Workshop participants studiedpractical river restoration techniques and riverecology on the South Dandalup and Serpentinerivers.
The workshop was an opportunity for thoseinvolved in river management to learn how totackle the erosion and sedimentation problemscommon throughout the waterways of WesternAustralia. A mix of theory and fieldwork was used to equip practitioners with the skillsand knowledge to combat these problems onthe ground. Lecture topics included streamhydrology, channel stabilisation design, revege-tation techniques and Aboriginal heritageissues. Participants conducted channel surveys
and foreshore assess-ments, analysed theirresults, and produceda rehabilitation designfor their allocatedreach.
It is currentlyplanned to hold twofurther workshops aspart of the South WestRiver Restoration, Training and DemonstrationProgram. The Program is jointly funded by theWater and Rivers Commission and the NaturalHeritage Trust.
For further informationBill Till, Protection and Enhancement SectionWaters and Rivers CommissionPO Box 6740, Hay Street, East Perth WA 6892Tel: (08) 9278 0561, Fax: (08) 9278 0587E-mail: [email protected]
River Restoration Workshop
Dates for your diaryThe Second Managing and Growing Trees Training Conference is onbetween 19–21 October 1998.
This conference is a great opportunity for those involved in managingand growing trees and other vegetation to exchange information andresearch results, participate in training workshops, and catch up on thelatest developments in farm forestry and vegetation management.
For detailshttp://www.dnr.qld.gov.au/fiqweb/news/news.htm
MODSS ‘99 International Conference The Department of Natural Resources will host the Second InternationalConference on Multiple Objective Decision Support Systems for land,water and environmental management. The conference will run from1–5 August 1999.
For detailshttp://www.dnr.qld.gov.au/events/modss99/index.htm
ueenslandQ
estern ustraliaW AThese workshops are based and modelledon the work of Dr Bob Newbury, a streamhydrologist from British Columbia,Canada. He visited Australia andconducted LWRRDC-funded workshopsin Victoria and Queensland in 1996, and inTasmania in 1997 (see issue 9 of RipRap)available from LWRRDC.
News grabQueensland is also amending legislation totighten up rules governing the allocationand approval of sand and gravel extractionfrom rivers and streams. These changesseek to better coordinate the legislativerequirements of the various state and localgovernment agencies involved in suchapproval processes.
For further informationJohn Amprimo, Department of Natural ResourcesGPO Box 2454, Brisbane QLD 4001Tel: (07) 3224 7668, Fax: (07) 3224 8359E-mail: [email protected]
CASE STUDY INFORMATION
IssueThe effects of large dams on tributary streamsentering a river downstream of a storage can incurvery expensive remedial works. In the case ofPindari Dam, on the Severn River near Ashfordin northern NSW, the effects on the Oakey Creektributary have been particularly severe, damagingproperty and roads, as well as having a significantimpact on mainstream sedimentation.
BackgroundThe Pindari Dam has, since its construction in1969, stored most of the small floods occurringin the catchment.The result of this has been thatflows downstream of the storage after smallfloods have been very low. The effect of this onOakey Creek, which joins the river below thedam, is that during flood events the usualbackwater from the main stream no longeroccurs, with the tributary flows descendingrapidly near the confluence. These faster flowsare causing erosion of the stream bed, with someof the banks along Oakey Creek collapsing, andsevere undermining of the roadway taking place.A further complication, or compounding effect,has been the construction of a new roadwayculvert crossing. During flood events, the culvertbecomes blocked with debris, resulting in acascading waterfall across the road.
16 THEME GETTING A GRIP IT’S A WRAP
ew outh alesS WNStrategies and treatmentsThe treatment designed to address this problemhas been to reduce the slope of the tributarystream bed by raising the creek bed near the confluence.This involved constructing a rockbed control structure two metres high. This wasinsufficient to protect the roadway, so a furtherlog structure one metre high was placed betweenthe road and the river to further reduce thegrade. The final works to protect the roadwayused rockwork to protect the stream banks andform an energy dissipator.
Over the next few months, the tributarystream will be fenced and the banks planted outwith indigenous vegetation. The figure belowshows a cross section of Oakey Creek whichdemonstrates the relative levels of the structures.These works are now being monitored to seewhether they are successful in addressing theerosion and related problems.
For furtherinformationPeter Wem, Riverine Corridor ProgramDepartment of Land and Water ConservationPO Box 3720, Parramatta NSW 2124Tel: (02) 9895 7029, Fax: (02) 9895 7845E-mail:[email protected]
In the first year, the project will be trialed in six sub-catchments, drawnfrom rural, urban and nature conservation areas across the UpperMurrumbidgee Catchment.This pilot project will:~ bring together scientists and community groups to test and evaluate
existing catchment health indicators;~ facilitate the transfer of scientific information to the wider community;~ test the usefulness of catchment health indicators to direct community
action; and,~ prepare and explore community responses to the use of catchment
health indicators in environmental management.
A three year pilot study is being conductedwithin the Upper Murrumbidgee Catchment toinvestigate the application by community groupsof catchment health indicators. The focus of theproject is on biophysical indicators, however,social and economic indicators will also beexplored.
The project aims to develop a method thatcan be used by community groups to measureand monitor trends in the health of their localcatchments.
ustralian apital erritoryA C TCatchment Health Indicators — A pilot study in the Upper Murrumbidgee Catchment
17INFORMATION
Gaining a better understanding of how ourstreams work, and providing some answers torestoring the nation’s waterways, will be the key aims of the Second Australian StreamManagement Conference, to be held in Adelaide,8–11 February 1999.
The conference is being presented by theDepartment of Environment, Heritage andAboriginal Affairs, the CRC for CatchmentHydrology, the River Basin Management Societyand the CRC for Freshwater Ecology.
During the past decade, there has beenenormous enthusiasm for returning many of the natural values to our Australian streams.Thisis being supported by hundreds of millions ofdollars from many quarters: the CommonwealthGovernment’s Natural Heritage Trust, StateGovernment Agencies, local government, urbanand rural river management authorities, pluscommunity groups and individual landholders.
Some people argue that we know all we needto know in order to rehabilitate our streams —it’s just a matter of getting on with it!!!
But do we really know enough and whatmore do we need to know? What are theremaining barriers to implementation —technical, political or social? What can we achievein the next five years? The next 25 years? Whatcan we learn from experiences overseas?
THEME CASE STUDY GETTING A GRIP IT’S A WRAP
outh ustraliaASThe challenge of rehabilitating Australia’s streams!
The conference will explore the technical/scientific, institutional and community aspects ofstream restoration. A series of field trips willenable conference delegates to visit an array ofurban/rural stream restoration projects, all locatedwithin one hour from Adelaide. You can alsoexpect a most unorthodox work shop session that will cut to the core of what this conference isall about.
The venue, the Hotel Adelaide International,is located five minutes from the CBD, on the‘happening strip’ of O’Connell Street. The striphas a great selection of restaurants and cafes,all within five minutes walk of the venue.Accommodation at the Hotel Adelaide will be ona first come/first served basis. Budget accommo-dation will be available from $32 per night.
The registration fee for the conference willnot exceed $430, with concessions available forstudents, landholders, community leaders andmembers of the River Basin ManagementSociety.
For further informationJim Burston, Conference ConvenerDepartment for Environment, Heritage and Aboriginal Affairs2/85 Mount Barker Road, Stirling SA 5152Tel: (08) 8200 3823, Fax: (08) 8339 7112E-mail: [email protected]
This collaborative project between EnvironmentACT, CSIRO, CRC for Freshwater Ecology and the Upper Murrumbidgee Catchment Co-ordinating Committee is being funded by aNatural Heritage Trust grant.
WEB itesStreamline on the WebAustralia’s natural resourcesdata base is now on the webhttp://www.infoscan.com.au
Riparian bibliographyInformation about ripariancommunities and related topicshttp://www.npsc.nbs.gov.resource/literatr/riparian/riparian.htm
s
CASE STUDY INFORMATION18 THEME GETTING A GRIP IT’S A WRAP
Integrating land and water managementVictoria has recently established nine CatchmentManagement Authorities (CMAs) in ruralregions to take a lead role in integrated land andwater management.
The CMAs provide integrated planning for land and water management, as well asproviding services in floodplain management,rural drainage, coordination/management ofwater quality and management of HeritageRivers outside of National Parks.
With their establishment Victoria has, for thefirst time, authorities that provide an integratedfocus on river management.They are essentiallya ‘custodian’ of river health in their area. As partof this role they are developing integratedwaterway health plans.
In addition, the CMAs will take a lead role inVictoria’s Stressed Rivers Program. CMAs are todevelop, within two years, river restoration plansto improve the condition of those prioritystressed rivers identified in their region.The riverrestoration plans developed by the CMAs willspecify objectives to improve river health, as wellas provide information about a range of mecha-nisms to achieve these objectives. The plans willinclude mechanisms to enhance the environ-mental flow regime and improve instreamhabitat. It is hoped that the implementation ofthese plans will result in river rehabilitation andstreamside revegetation.
For further informationJulia Reed, Waterway Management UnitDepartment of Natural Resources and Environment6/232 Victoria Parade, East Melbourne VIC 3002Tel: (03) 9412 4145, Fax: (03) 9412 4049E-mail: [email protected]
Publications from VictoriaOther recent Victorian initiatives in waterwaymanagement include the publications of:~ the Index of Stream Condition: Reference
Manual, User’s Manual and Trial ApplicationsThe index (ISC) provides an integratedassessment of river condition which incor-porates assessment of five components of streams, namely, hydrology, water
ictoriaVquality, physical form, streamside vegetationand macroinvertebrates. The assessmentproduces an indicator value for each of thesefive components; the sum of the indicators is the Index of Stream Condition. Trialsshowed that the ISC is a useful tool forguiding management actions and bench-marking and assess the environmental condi-tion of streams.
~ Rapid appraisal of the economic benefits of rivermanagement: guidelines and examplesThis two volume report describes economicevaluation approaches which can be appliedto waterway management strategies andprograms for setting priorities for investmentof scarce resources.
~ Victoria’s Environmental Flow Program: a keycomponent of integrated river managementThis brochure outlines Victoria’s approachto improving the environmental health of waterways. The two stage programfocuses initially on defining and cappingexisting rights to water, and where possible,improving environmental flows. Stage 2involves identifying stressed rivers, settingpriorities for action and the developmentand implementation of comprehensive workprograms to restore their environmentalhealth.
~ Rural Drainage in Victoria: a scoping studyThis study collated information on thecurrent extent of different types of ruraldrainage in Victoria and the impacts of thisdrainage on waterways as well as assessingstatutory and administrative mechanisms tocontrol drainage.
~ Willows Along Victorian Waterways: towards awillow management strategyThis report provides a clear understandingof the issues surrounding willows and a focusfor management into the future.
To obtain copies of these publicationsCarol Roberts, Waterway Management UnitDepartment of Natural Resources and Environment6/232 Victoria Parade, East Melbourne VIC 3002Tel: (03) 9412 4083, Fax: (03) 9412 4049E-mail: [email protected]
19INFORMATIONTHEME CASE STUDY GETTING A GRIP IT’S A WRAP
Do you want riparian facts fast? Due to popular demand, the Riparian Management IssuesSheets are being reprinted. These Sheets cover a range of topicsincluding stock management, bank stability, water quality andsnag management. If you would like to place an order for a setof these issues sheets please fill in the coupon below.
Clip or copy this coupon ☛and return to
Dr Siwan Lovett, LWRRDC Program CoordinatorRiparian Lands R&D ProgramLand and Water ResourcesR&D CorporationGPO Box 2182, Canberra ACT 2601Tel: 02 6257 3379, Fax: 02 6257 3420E-mail: [email protected]
Some LWRRDC publications are available from the DPIE Shopfront situated in the Edmund Barton Building,Core 2 Entrance (off BlackallStreet) Barton ACT 2601Tel: 1800 020 157
Disclaimer The information in this publication has been publishedby LWRRDC to assist publicknowledge and discussion andhelp improve the sustainablemanagement of land, waterand vegetation. Wheretechnical information has been provided by or contributed by authorsexternal to the Corporation,readers should contact theauthor(s) and make their own enquiries before makinguse of that information.
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