Tips for how to be a
Riversmart Farmer
This project is supported by Riversmart Australia Ltd, through funding
from the Australian Government’s Caring for our Country
Acknowledgements
Riversmart Australia Ltd would like to thank the
following for their help with the assembly of this
guide. Comments were provided on the draft by
members of the Riversmart Advisory Board and
Pip Job from the Little River Landcare Group.
It will also remain a ‘living’ document as it is used,
field tested and improved through the Macquarie
River NatureLinks project starting in September
2012 in collaboration with the Macquarie 2100
Landcare Group.
Thanks also to the Central West Catchment
Management Authority for their ongoing support
and in particular to Shona Whitfield for her editorial
and content inputs and suggestions. Matt Hansen
provided some of the fish-related photographs.
Thanks also to David Barnes (NSW DPI
photolibrary) for all the help with gaining approvals
to use a number of photos from their collection
and for providing the high resolution versions.
Likewise Keryn Lapidge (Invasive Species CRC)
and Michael Dickinson (Australian Willdife and
Feral Management) helped source the feral photos
and Megan Power (www.westernweeds.org) did
the same for several of the weeds photos. Dr Deb
Nias (Murray Darling Wetlands Ltd) kindly provided
the acid sulfate soil photo and Dr Rhonda
Butcher from Water’s Edge Consulting the photo
and guidance on grazing and wetlands. Other
photographs kinds provided by Dr Max Finlayson,
Jason Higham, Anthony Townsend, Sarah Moles,
Fern Hames, John Lollicato, David Scadding,
Jonathon MacPhail, Gunther Schmida (MurrayDarling Basin Authority) and the Lippia Working
Group – GHD.
This guide is a digest of many other prior
publications – all of which are duly acknowledged
– and to the various organisations and individuals
who were responsible for this guidance and
advice, we say thank you for allowing us to quote
and cite your works, and, in many cases use
photographs from your publications.
2
As always, special mention is due to Philippa
Lawrence and Sprout Design for the very professional
layout and design. Thanks also to Jenny Andrew for
proof editing.
Finally, thank you to the Australian Government for
supporting this project through the Community
Grants component of the Caring for our Country
program.
Disclaimer
RiverSmart Australia Ltd do not warrant or make any
representation regarding the use, or results of the
use, of the information contained herein as regards
to its correctness, accuracy, reliability, currency
or otherwise. RiverSmart Australia Ltd expressly
disclaim all liability or responsibility to any person
using the information or advice.
Citation
This publication should be cited as follows:
Riversmart Australia Ltd, 2012.
Tips for how to be a Riversmart Farmer
For further information about this guide contact
Dr Bill Phillips, CEO of RiverSmart Australia.
Email: [email protected]
Copyright
This work is copyright. Unless permitted under
the Copyright Act 1968 (Cwlth), no part may be
reproduced by any process without prior written
permission from Riversmart Australia Ltd or the
authors of cited publications. Requests and inquiries
concerning reproduction and rights should be
addressed to Dr Bill Phillips, CEO of RiverSmart
Australia (see contact details above). All photographs
are the property of the photographers unless
otherwise indicated and should not be used without
their express permission.
Cover photographs
Acknowledgments: Right – Michelle Donlan.
Left – Matt Hansen. Centre – Tim Gardiner.
Thanks to the Central West Catchment Management
Authority for allowing the use of these images.
Tips for how to be a Riversmart Farmer
Tips for how to be a Riversmart Farmer
The concept of RiverSmart farming is quite simple
– minimising your river ‘footprint’ and even going
the next step and helping to rehabilitate your
nearby river, creek or wetland. This will give onfarm benefits as well as assist catchment-wide
efforts.
The advice provided here is designed to give
you, the landholder information about the range
of ways your farm might currently be impacting
on river health without you even knowing it.
It’s designed to give you information that you
can then apply to modify your management
practices and maybe then reflect into a Property
Management Plan or associated vegetation or
water management plan, if you so wish.
It’s important to note that if you have river
frontage, floodplain country or creek lines that
drain into a river system, chances are there are
things you could be doing to help maintain or
improve water quality, to help bring back native
fish and other wildlife and generally increase
the opportunities for enjoying a healthy and
vibrant river.
Getting started
These guidelines are designed to allow you to
systematically review your situation and then
consider information and ways to modify your
farming practices, if appropriate and feasible.
Fundamentally we all impact on our nearby rivers
through the volumes of water we use, the quality
of the water that we return to our rivers and the
activities we undertake either close to or in places
Tips for how to be a Riversmart Farmer
where those impacts are ultimately felt in the river.
So it’s basically about water quantity, water quality
and landuse practices.
In this guide the issues surrounding water use
efficiency are not considered. All farmers are
acutely aware that being efficient with water
has many drivers; economics and sustainability
among them. From a river health perspective it is
well known that Australia’s inland rivers thrive on
variable flows and so periods of drought and floods
are what they’ve adapted to cope with. However,
there are signs in many inland rivers that we need
to find ways to provide (a) higher base flows, and
(b) attempt to manufacture variable flows that mimic
nature. Both mean there is an ecological imperative
for being as frugal with water as we can in order
to have the capacity to do these two things.
Modernising irrigation infrastructure is one key step
needed in this direction to reduce transmission and
application losses for example. This is just smart
business and will help the community collectively
to take pressure off our rivers and see them
maintained as healthy lifelines of rural Australia.
In the following pages we’ve assembled a series
of summary descriptions of the key issues a
Riversmart farmer should consider and these
are organised under obvious themes (parts). The
topics they cover are listed on the next page. Each
has a standard format and will also aim you in the
direction of more detailed information if you wish
to know more. You could also consult with your
local natural resource or catchment management
agency, or Riversmart. Our contacts details are on
the web site www.riversmart.org.au
3
Contents
1. Maintaining healthy riverbanks and creek lines . . . . . . . . . . . . . . . 1–1
Areas of bare ground are a no-no . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–2
The importance of buffer zones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–3
Combating gully erosion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
2. Being a fish-friendly farmer . . . . . . . . . . . . . . . . . . . . . . . . . . 2–1
Looking after snags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2
Helping native fish to migrate and find mates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–3
Reducing fish injuries and deaths in pumps and irrigation channels. . . . . . . . . . . . . . . . . . . . . 2–5
3. Reducing waterway pollution . . . . . . . . . . . . . . . . . . . . . . . . . 3–1
Maintaining healthy vegetation along drainage lines, creek
and your river frontage – see Part 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–1
Buffer zones as a key management tool. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–2
Reducing impacts at creek or river crossings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–3
Disposing of farm effluents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–4
Reducing spray drift. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–5
Minimising fertiliser and chemical-rich run-off into waterways. . . . . . . . . . . . . . . . . . . . . . . . . . 3–6
Dealing with salinity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–8
Fire, rivers and wetlands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–9
Black water events. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–10
Waste management from the homestead, workshop and farm sheds. . . . . . . . . . . . . . . . . . 3–10
4. Wetlands working for you . . . . . . . . . . . . . . . . . . . . . . . . . . . .4–1
Managing your stock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–2
Cautious lake bed cropping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–4
Using wetlands to clean potentially damaging run-off or effluents . . . . . . . . . . . . . . . . . . . . . . 4–5
Some of the risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–5
5. Keeping feral pest under control . . . . . . . . . . . . . . . . . . . . . . . .5–1
Reducing the damage caused by feral pigs, rabbits or goats. . . . . . . . . . . . . . . . . . . . . . . . . . 5–1
Doing something about bloody carp!. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–2
What we know about Redfin and Gambusia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–3
6. Weed worries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–1
Willows – from a river health perspective they are bad! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–1
Lippia crippling our floodplains into watercourses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–3
Alligator weed – it might only be a matter of time! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–5
Salvinia – pray it doesn’t come near you!. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–6
Other weeds to worry about . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–7
4
Tips for how to be a Riversmart Farmer
1.Maintaining healthy riverbanks and
creek lines
From a healthy waterways perspective, ideally the
areas along and surrounding your river frontage,
drainage lines (such as creeks or streams), and
wetlands should be well vegetated with native
plants, and with no woody weeds or bare areas
impacted by overgrazing from stock, feral animals
or kangaroos.
Some of the values of having a well vegetated
riparian zone are:
• They act as buffer zones, protecting the river
from direct soil erosion and loss.
• Well vegetated riparian zones also help buffer
the river from runoff that may be high in
nutrients (phosphorus and nitrogen especially)
that contribute to the formation of algal blooms.
• They provide habitats for native wildlife.
• As they grow old, riparian trees may fall into the
river creating valuable habitat for native fish.
• Native vegetation along rivers also contributes
food items for aquatic species such as insects
and organic materials.
The dense foliage in the riparian zone of this creek in the Upper
Macquarie catchment ensures the banks of the creek are stable
and in-stream habitat is healthy. Photograph: Central West CMA.
If the waterways are permanent or semipermanent then chances are they’re offering
environmental values such as providing spawning
areas for native fish. On the downside they may
also be spawning areas for carp, and if so, see
Part 5 – Keeping feral pests under control.
The benefits of native vegetation in riparian areas. Illustration Paul Lennon in Lovett, S & Price, P (eds) (2007),
Principles for riparian lands management, Land & Water Australia, Canberra.
Tips for how to be a Riversmart Farmer
1–1
1. Maintaining healthy riverbanks and creek lines
Areas of bare ground are a
no-no
Riverbank or riparian areas that have become
bare, with little or no vegetation cover are among
the most serious threats to healthy river systems.
If stock are causing the problem and entering
the water they will be pugging the wet soil,
accelerating soil erosion and defecating in the
water; both of which have serious downstream
impacts on water quality for all users including
neighbouring farmers.
Cattle pugging—a major problem for waterways with soil
erosion being accelerated and weeds encouraged to move in.
Photograph: Bill Phillips.
The presence of woody debris, overhanging native vegetation
and clean water are key habitat elements for a range of native
aquatic species. Photograph: Central West CMA.
Exposed areas are also prime targets for weed
invasion (see Part 6 – Weed worries) and they
contribute to soil erosion and increased sediment
load in the river, increasing turbidity (see Part 3
– Reducing waterway pollution also). This in turn
decreases light penetration limiting the growth of
aquatic plants which in turn impacts on the natural
food webs of the river.
Vegetation along rivers also helps buffer them
from potential pollution during rainfall events
when runoff may contain nutrients and other farm
chemicals, herbicides, pesticides, insecticides,
etc. By reducing nutrient-laden runoff reaching the
river, one of the key ingredients of algal blooms is
reduced (see Part 4 – Wetlands working for you).
Bare and exposed riparian zone: a prime candidate for major
soil erosion and possible weed invasion. Photograph: Central
West CMA.
The other value of native vegetation buffer zones
in riparian situations is that they provide wildlife
habitats and create riverine corridors for terrestrial
fauna. Also, as trees age some will fall into the
river making snag habitats for native fish (see Part
2 – Being a fish-friendly farmer). Unlike deciduous
woody weed species, native vegetation doesn’t
drop its leaves in autumn—a phenomenon that has
major impacts on water quality (see Part 6 – Weed
worries).
What you can do
• The typical causes of degraded riparian
vegetation are uncontrolled grazing by stock
and kangaroos, feral pigs and goats, farm traffic
or all of these. Control measures, or ways to
restrict access to these sensitive areas should be
considered.
1–2
Tips for how to be a Riversmart Farmer
Alternative watering point for stock. Photograph: Central West
CMA.
• Once stock, and/or feral pests are controlled,
rehabilitation of the exposed areas can begin
(see below). This type of work is a high priority
for many government funding programs so you
can seek advice on how to access this type
of support, if you wish. For reasons explained
in Part 6 – Weed Worries, the use of native
species is recommended for rehabilitating
degraded areas.
The importance of buffer
zones
From a Riversmart farm planning perspective we
recommend you consider retaining or creating
buffer zones along all drainage lines, around
wetlands and even farm dams if they are arranged
like a chain of ponds down a creek line.
The benefits are numerous. Apart from stabilising
the land and reducing soil erosion, buffer zones
also reduce wind erosion, reduce spray drift into
sensitive areas, and provide shelter for stock.
Buffer zones can also help reconnect wildlife
habitats and encourage species such as bush
birds to move through your property, some of
these providing natural insect control.
See more about buffer zones in Part 3 – Reducing
water pollution.
Ideal situation with wide buffer zone lining the river.
Photograph: Sam Davis, NSW DPI.
Stock exclusion fencing and replanting to restore a healthy
creek. Photograph: Central West CMA.
Cows drinking from off-river watering point. Photograph: Chris
McCulloch, Central West CMA.
Tips for how to be a Riversmart Farmer
1–3
1. Maintaining healthy riverbanks and creek lines
• If the bare, exposed areas are caused by stock
grazing the riparian margin and drinking in the
river, then exclusion fencing and off-river drinking
points are recommended (see below).
1. Maintaining healthy riverbanks and creek lines
Combating gully erosion
The following is based on the Gully Erosion Fact
Sheet (October 2008) produced by the Central
West Catchment Management Authority.
Stock that are allowed uncontrolled access to
creeks will tend to routinely follow established
tracks or trails. Over time these become worn and
free of vegetation. Gully erosion can then result
and spread out from the initial point of soil loss.
If left uncontrolled large scale gully erosion can
result (see at right). Ruts left by farm machinery
or excessive intensive farming that reduces soil
structure and stability can also be causal factors.
Gully erosion results in soil loss from your farm
and ongoing loss of productive land if not
addressed. It can also result in the transported soil
impacting on water quality further down the creek
or possibly in the river it drains into. Nutrients may
also be carried with the soil, further exacerbating
downstream water quality problems like algal
blooms. Soil deposition in the creek or river will
have a negative impact on habitat for species like
native fish, platypus, etc.
Severe gully erosion. Photograph: Tim Gardiner, Central West
CMA.
What you can do
• Be vigilant—check for potential gully erosion
start points such as exposed areas resulting
from vehicles or stock movements, drainage
lines across overgrazed paddocks, etc.
• If you have gully erosion, first establish if it is
active. In other words, is the drainage line or
pathway continuing to cut into and move up
the slope? Are the gully walls close to vertical
and is the base still lowering? Regular photos
for a standard (star picketed) site will help you
monitor the situation.
• If the gully is still active try to establish where
water is coming from—is it groundwater,
surface water, or both? Depending on the
situation you may need simple or more complex
solutions.
Gully erosion undermining trees and depositing soils into the
nearby river whenever it rains. Photograph: Shona Whitfield.
Erosion control measures using rocks to stablise banks and
slow flows. Photograph: Central West CMA
1–4
Tips for how to be a Riversmart Farmer
Sources and further reading
Channel erosion. Fact sheet produced by the
Central West Catchment Management Authority.
October 2008.
Degradation of native riparian vegetation
along NSW water courses. Primefact 12. NSW
Department or Primary Industries, June 2005.
Gully erosion. Fact sheet produced by the Central
West Catchment Management Authority.
October 2008.
Livestock management. Fact sheet produced
by the Central West Catchment Management
Authority. October 2008.
Living and working on a riverbank. NSW DPI.
Date unknown.
Revegetation and stock exclusion to reduce erosion.
Photograph: Central West CMA.
If the erosion is less severe then a range of
management options are regularly recommended
depending on the situation. These include:
• Address the primary cause(s)—change vehicle
or stock routes or remove stock from the site
altogether to allow recovery.
Management and rehabilitation of riparian lands.
A best management practice guide for the Central
West. Central West Catchment Management
Authority. October 2008.
Riparian vegetation. Fact sheet produced by the
Central West Catchment Management Authority.
October 2008.
• Revegetate the exposed, vulnerable areas with
groundcover (grasses etc). The rule of thumb is
to have a minimum of 70 per cent cover.
• Allow regeneration of the natural plant
community-shrubs etc as well as the
groundcover to help stabilise the effected
landscape.
• If groundwater discharges are part of the
problem use deep-rooted perennial grasses
both in and around the effected gully.
In the 1990s, this gully west of Molong was fenced and replanted
with native trees and shrubs. Since that time, the erosion on the
site has been dramatically reduced, and habitat features are now
starting to develop. Photograph: Central West CMA.
Tips for how to be a Riversmart Farmer
1–5
1. Maintaining healthy riverbanks and creek lines
• If the water source is both ground and surface
water and the erosion severe, earthworks or
other engineering fixes may be required. You
should seek professional advice.
2. Being a fish-friendly farmer
Many of the issues considered below are also
discussed in the excellent NSW DPI publication
‘7 Key Tips for Fish Friendly Farms’.
As a farmer there are many ways you could be
part of ensuring the river has a lot more native fish,
and let’s face it who doesn’t like to go fishing!
Across the Murray-Darling Basin it is estimated
by experts that native fish populations are about
10 per cent of what they were when white settlers
came to Australia.
There are many reasons for this decline in
numbers and for several species moving into the
threatened and endangered categories.
Fish need healthy river banks
Healthy rivers make more fish and for this to occur
we need well vegetated banks. Riverside native
vegetation is a vital part of having more fish in the
river. This vegetation drops insects and leaves
into the river and these are eaten by fish, or by the
things some fish like to eat, such as yabbies and
shrimps. As trees age they fall into the river and
make instant fish homes – snags (see page 2–2).
In contrast, river banks that are bare due to stock
trampling, overgrazing or vehicle traffic are prime
candidates for erosion and this soil, once washed
into the river, makes the water muddy, reducing
aquatic plant growth, and silting up the river. All
of these things aren’t good for native fish. Aquatic
plants are a food source and a place for young
fish to hide from predators, and siltation fills the
big holes where most fish like to hang out.
So, if you go fishing remember this when you’re
using dirt tracks or launching your boat off a
beach – don’t rip up the ground as that soil will
end up in the river.
Clean water = more fish
Poor water quality comes about in many ways
– erosion is one, fertiliser-rich run-off and urban
stormwater are others. Litter dropped in the street
or at camp sites can make its way into our rivers
and this makes them ugly, but also impacts on
river life.
Tips for how to be a Riversmart Farmer
Ben Moore shows off his catch on the Macquarie River... shortly
before releasing this important breeding animal back to help make
more fish for the future! Photograph supplied by Matt Hansen.
Think about this when you’re out on your nearby
river especially – take all your rubbish home, and
why not take a spare plastic bag with you and pick
up what some other less thoughtful person might
have dropped or left behind.
Things that block fish migration
Another issue is that the dams, weirs and even
some road crossings we’ve installed stop fish
migrating. Many of our native fish species are
migratory while others routinely go looking for
mates during the breeding season, better food
opportunities or to escape adverse conditions. If
prevented from doing this, breeding success is
reduced, meaning less fish to catch. On page 2–3
this is considered further.
We also know that there are less native fish
around today due to factors like diseases,
introduced pest fish (see Part 5) and overfishing.
Don’t be greedy
Today, catch and release fishing is encouraged as
a way to make sure your kids (and theirs) have fish
to catch. Basically, don’t take more than you need
for a feed. The days of bragging over a freezer full
of fish are gone! And, make sure the bigger fish
you catch are let go to keep on breeding – they’re
our fish factories (and usually taste like old boots
anyway).
2–1
2. Being a fish-friendly farmer
Looking after snags
Snags are large woody objects, such as whole
trees, root balls or major branches that fall into the
river. In the early days many snags were removed
from rivers to help with safe navigation by river
boats. We now know that snags provide important
spawning sites for native fish, places for young
fish to hide from predators, and to help protect the
river bed and bank from erosion.
A river with this amount of snags is perfect for native fish – lots
of places to hide from predators and also hang out to ambush
prey. Sadly, the bank in the foreground is badly eroded from
uncontrolled stock access. Photograph: Bill Phillips.
Mick Coad with the Macquarie River Yellowbelly (Golden perch).
Photograph supplied by Matt Hansen.
Fish by the rules
Sadly there are still people out there wanting to
cheat by using illegal fishing gear or practices and
ignoring the well known rules. If you come across
illegal fishing activities or gear on your property
or river frontage – simply call your local fisheries
officer (1800 043 536) and report it. Leave it to the
pros to deal with these situations.
If you’re a keen angler, get hold of a copy of
Macquarie River Fishing Trail Guide (www.
rivertrails.com.au). It will also explain how you can
be a Riversmart angler.
2–2
Macquarie River during the drought showing exposed snag (top)
and the same snag at normal river heights (bottom). Such snags
are vital habitat for native fish. Photograph: Bill Phillips.
Research has shown that most Murray cod are
found within a metre of a snag and streams with
snags usually have greater numbers of native fish.
Of course, sometimes big log jams of woody
material can block rivers and make flooding worse.
In such situations these need to be cleared. This
is work that should be done by professionals, so
contact your appropriate government department
if this occurs.
Tips for how to be a Riversmart Farmer
Many of our native fish species are migratory while
others routinely go looking for mates during the
breeding season, better food opportunities or to
escape adverse conditions.
Narrabri Creek, NSW. Resnagging at low river level—seek
expert advice before attempting this! Photograph: Anthony
Townsend.
Without realising it, some farm and road
infrastructure can prevent these important fish
movements. For example, long, narrow and dark
pipe culverts routinely used for making road
crossings (see photographs below) will discourage
fish passage. If the ends of the pipe are ‘perched’,
as in the example shown on the next page, then
this can also prevent fish passing through.
What you can do
• If your part of the river looks to have few
snags, consider contacting your local fisheries
department to get their advice on how to go
about re-snagging. There are some ‘do’s and
don’ts’ to making this work so don’t try this
without first seeking advice.
• Of course, if you don’t have well vegetated
river banks then there won’t be any way nature
can ‘install’ snags for you so this is another
reason why having a healthy riverbank of
native vegetation is so important—see Part 1 –
Maintaining healthy river bank and creek lines.
‘Before’ and ‘after’. Round pipes replaced with box culverts to
make this more fish friendly. Photographs: NSW DPI.
Equally, elevated flat-bed road crossings (see
below) act the same as a weir from a fish
perspective and prevent any attempt to move
upstream.
Maybe you have weirs or similar structures that
are now redundant or unsafe—removing these will
certainly benefit native fish (see next page).
Murray cod taking refuge in snag habitat. Photograph: NSW DPI.
Road crossings restrict access to upstream habitat for native fish.
Photograph: NSW DPI.
Tips for how to be a Riversmart Farmer
2–3
2. Being a fish-friendly farmer
Helping native fish to migrate
and find mates
2. Being a fish-friendly farmer
• Or maybe you have redundant or unsafe weirs
or culverts—why not consider removing them to
help our native fish—see below, and page 3–3.
Long, narrow pipe culverts like these are not ideal for allowing
native fish to pass through. Note how the sill level is below
the pipes meaning water will move through with high velocity
making passage for small fish problematic.
A suitably designed rock ramp can help address gully erosion
problems and also allow for fish migration up river to overcome
concrete weirs like the one above. Photograph: Central West CMA.
Removing old, redundant or unsafe weirs and culverts will
all help our native fish recover even if only on a much smaller
scale to the situation above. Photograph: Shona Whitfield.
What you can do
• If you’re considering the installation of a pipe
culvert consult with an expert in the fisheries
area of government to get advice on size
and placement etc. Setting the sill height
can be important in terms of ease of use
for small native fish especially. These days
broader rectangular form concrete culverts are
recommended to help fish movements and if
there is scope to do so these can be lined with
rocks and even have a grill or grate at the top to
shed light into the culvert.
Fish-friendly rock ramp which also helps reduce erosion.
Photograph: Jason Higham.
• Also, if you have an existing culvert system
make sure it doesn’t have accumulated debris
or a washed away ‘step’ that may be preventing
native fish movement.
• If appropriate, consider installing a rock ramp or
similar type of ‘fish ladder’ (see photos at right)
to ensure your culverts are not preventing fish
migrations. Again, before doing this seek advice
from an expert.
2–4
Tips for how to be a Riversmart Farmer
2. Being a fish-friendly farmer
Reducing fish injuries
and deaths in pumps and
irrigation channels
Recent research in Australia has shown that
irrigation infrastructure is having a significant
impact on the survival of young native fish.
It seems that millions of fish are regularly being
injured, killed and otherwise removed from
main river channels by water infrastructure. For
example, on the Namoi River, in some instances
more than 200 fish were extracted by a single
irrigation pump each day.
Another potential problem is the rapid draw down
of irrigation systems which can leave fish stranded.
End of irrigation season sampling on the Mulwala
canal system found stranding and entrapment of
almost one million fish of 14 different species.
As we learn about this problem, more and more
farmers who draw water from our rivers, operate
irrigation channels or maintain on-farm storages or
wetlands are working with authorities to find ways
to reduce this impact.
What you can do
• If you’re concerned that your farm may be
inadvertently contributing to the death and injury
of native fish it is suggested you contact your
local fisheries authority for advice on the latest
technology and management practices being
developed to address this problem.
Rapid draw down of irrigation channels can strand large
numbers of native fish. There are ways to reduce this impact.
Photographs: Bill Phillips.
Sources and further reading
7 key tips for fish friendly farms. NSW Department
of Primary Industries. http://www.dpi.nsw.gov.au/
fisheries/habitat/publications/farming/7-key-tips-fora-fish-friendly-farm
Barriers to fish passage. NSW DPI Primefacts and
Fishnotes. September 2001.
Baumgartner L.J., Reynoldson N., Cameron L.
and Stanger J. (2007). The effects of selected
irrigation practices on fish of the Murray-Darling
Basin. NSW Department of Primary Industries and
Murray-Darling Basin Commission. http://www.
dpi.nsw.gov.au/research/areas/aquatic-ecosystems/
outputs/2007/901
Fairfall, S. and Witheredge, G. (2003) Why
do fish need to cross the road? Fish passage
requirements for waterway crossings. NSW
Fisheries, Cronulla. www.fisheries.nsw.gov.au/
publications/aquahab.htm
Jones M., and Stuart I. (2004). Impact of flow
regulation structures on fish in the Barmah-Millewa
forest. Heidelberg, Victoria, Arthur Rylah Institute.
ISBN 1741069173.
Managing woody debris in rivers. Land and Water
Australia River and Riparian Land Management
Facts Sheets. No.7.
We now know that in-stream pumps are drawing up and
injuring or killing significant numbers of small native fish.
Photograph: Bill Phillips.
• Ways to reduce this impact are being trialled at
present.
Tips for how to be a Riversmart Farmer
2–5
3. Reducing waterway pollution
Waterways can become polluted through a variety
of pathways and in this section we examine a
few of the more common ways. As a Riversmart
farmer you need to be constantly vigilant and
asking yourself: Am I polluting our river? And if so:
How can I stop or reduce that impact? In some
instances you may not even realise you’re part of
the problem as the point of impact on the river
may be far removed from you, or it may be very
subtle.
Maintaining healthy
vegetation along drainage
lines, creek and your river
frontage
As explained in Part 1, this is perhaps the most
important step to take, as soil erosion has a huge
impact on our rivers. This can be caused by many
things including roads and tracks, uncontrolled
stock access, gully erosion, overgrazing of nearby
areas by stock and kangaroos, and for numerous
other reasons. Some of these issues are explored
in more detail below and were considered in Parts
1 and 4.
Buffer zones as a key
management tool
Strategically located buffer zones are an important
tool for reducing water pollution as they serve
to filter run-off as well as reducing wind-borne
pollution by things such as soil, pesticides and
insecticides. They can also offer the duel benefit of
providing wind breaks and stock shelter areas.
Buffer zones along drainage lines and
watercourses are a very simple and low-cost way
to help keep your nearby river or wetland healthy.
Yes, you have to sacrifice potentially productive
land but the whole of farm and downstream
benefits are worth it. If your upstream neighbours
aren’t doing the right thing—you bare the brunt
of that—so it’s also about doing the right thing by
other river and water users. Planning to operate
your farm with buffer zones in place and well
maintained is a wise move, especially if several
adjoining property-owners cooperate.
Management and rehabilitation of riparian lands. A best management practice guide for the Central West. Source: Central West
Catchment Management Authority. October 2008.
Tips for how to be a Riversmart Farmer
3–1
3. Reducing waterway pollution
Most States now recommend (or require) set
backs from sensitive areas with all forms of
cropping as well. Leaving a buffer zone between
the areas you plough, fertilise and cultivate will
also help minimise run-off into creeks and rivers,
while also helping to reduce nutrient-rich run-off if
it rains heavily after fertiliser application—fertilisers
are a primary cause of algal blooms in our rivers.
Buffer zones can be a nutrient-sink to help keep
these out of the river.
Coolbaggie Creek, NSW with healthy buffer zones of
vegetation along both banks. Photograph: Shona Whitfield
Retaining and maintaining buffer zones along rivers help
reduce run-off and spray drift impacts as well as keeping the
river ecology healthy. Photograph: Charlie Jenkins, NSW DPI.
What you can do
• If you have an aerial photo of your property look
in detail at each area focussing on the drainage
lines and places where your farming practices
sit close to these. Where you can, look to create
or preserve buffer zones.
• In some areas there are guidelines or rules
relating to buffers. For example, under the
NSW Native Vegetation Act 2003 a minimum
20 metre buffer is required between any
‘Routine Agricultural Management Activity’
and a watercourse. In some areas buffers of
up to 100 metres are recommended while in
most situations buffers around 30-60 metres
will do the job. The design and width of the
buffer can also be dictated by slope, soil and
what’s there already. Equally, the reasons for
having the buffer zone in place may alter how
you design it—see page 65 in Management
and rehabilitation of riparian lands: a best
management practice guide for the Central
West (Central West CMA 2008).
3–2
• If you’re not okay with heavily wooded buffer
zones you can still achieve good results with
using grass filter strips, although there are
limitations in some situation. The following
is relevant advice, and comes from the
Management and rehabilitation of riparian lands:
a best management practice guide for the
Central West (2008).
– Grass filter strips are particularly useful
where landholders are not keen on woody
plants and trees in the riparian zone. A grass
strip provides dense ground cover on the
flatter land approaching the river channel or
wetland; it primarily acts as a sediment trap
but also provides some stability.
– Grass strips need to be applied to areas with
effective surface drainage (for example, a
levee break). Grass filter strips are very good
at trapping sediment particles and are most
effective where overland flow is shallow (less
than one centimetre).
– However, grass strips can be ineffective on
hillslopes and difficult to establish in semi
arid areas or where trees are present and
shade out groundcover. Grass filter strips
may be more effective when combined with
other buffer strips by using the replanting or
regeneration techniques outlined previously
and combining them with strips of trees and
shrubs. (Central West CMA 2008)
Tips for how to be a Riversmart Farmer
Places where cars, tractors and livestock cross
waterways can cause major problems. “Vehicles
and stock traversing waterways on ford-type
‘wet crossings’ can stir up sediments, cause
erosion and increase turbidity. Cows are 50 times
more likely to defecate when crossing a stream
instream than on a raised crossing. Manure
increases organic nitrogen, suspended solids and
pathogens, and reduces water quality”. (Grove &
Lines-Kelly, NSW DPI, updated, 7 Key tips for a
fish friendly farm).
Even if the crossing is on a small creek line some
distance from the river, if it rains the stirred up
sediment, manure and urine will wash into the river
and cause problems there.
An example of how a stock crossing can be constructed to
minimise damage to the waterway. Illustration: Paul Lennon,
in Staton, J & O’Sullivan, J, (2006), Stock and waterways: a
manager’s guide, Land & Water Australia, Canberra.
What you can do
• Minimise use of causeways, especially for
moving cattle around the property.
• Maybe provide a rocky base for crossings to
reduce soil erosion and don’t let the stock loiter
in the water.
• Consider installing a timber bridge (see below)
or suitable concrete culvert (see Part 2 – Being
a fish friendly farmer) to keep stock and vehicles
out of the creek. This will also help native fish
movements. If constructing a bridge try to avoid
placing the foundations or footings in the river
or creek (see below).
A timber bridge spanning the waterway is likely to help
improve fish passage and water flow, and provided a safer,
more reliable crossing for local residents. Photograph:
Charlotte Jenkins NSW DPI.
Example of restricted stock access to water. Photograph:
Central West CMA
Tips for how to be a Riversmart Farmer
3–3
3. Reducing waterway pollution
Reducing impacts at creek or
river crossings
3. Reducing waterway pollution
Disposing of farm effluents
Some farming enterprises, especially intensive
stock production like pigs, poultry, feedlots,
and even dairy, create issues relating to animal
waste disposal. Likewise, some forms of irrigated
cropping can have as by-products tailwater
that may be unsuitable for discharge into
watercourses.
Such industries are heavily regulated these days,
with EPA legislation and other similar legislation
used to enforce certain codes of conduct. Holding
or tailing dams, effluent treatments ponds etc are
commonly used to improve the quality of water
from these activities before they are allowed into
rivers and streams.
For those landholders who operate feedlots
there are guidelines about minimum or set back
distances from water bodies such as streams,
wetlands, bores and dams and advice on
avoiding shallow or rising groundwater tables
or groundwater recharge areas. There are also
recommendations for how to deal with runoff
from rainfall. For example, it is suggested that
the feedlot should be located above the 100 year
flood level or flood prone land.
In some instances, returning well treated water to
rivers might provide a better outcome than reuse
by irrigation. These could be used to supplement
river flows. An example of this, is at the Taronga
Western Plains Zoo. Water from Cootha Creek is
used throughout the facility in animal enclosures
and other sites. This water is filtered through
a series of wetlands and finally returned to the
Macquarie River at equal or better quality than
before.
3–4
What you can do
1.Ensure that you have sited your infrastructure
away from all watercourses as mentioned
above.
2.Consult the appropriate departments to check
regulations and seek advice.
3.Use the latest innovations for reducing water
use or recycling. In this way you can help
decrease the amount of water taken from rivers
and wetlands.
Wetlands can sometimes be used to ‘polish’ farm effluent
waters before they flow back into rivers. Photograph: Chris
McCulloch, Central West CMA
Tips for how to be a Riversmart Farmer
Whether they are applied from the air, by tractor
or on foot there are risks that under certain
conditions there may be drift of herbicides or
pesticides onto non-targets, including waterways
or drainage lines. These impacts are now well
documented and there exists comprehensive
advice on best practice in this area.
Among the factors now considered important to
take into account are the following:
• Equipment chosen—this is a compromise
between droplet size and coverage.
• Volatility of the sprayed herbicide or pesticide.
• Spray height and direction—equipment and
weather factors may influence this.
• Size of the area treated—the larger the area, the
greater the risk of off-site impacts.
• The capture surface—the risks of drift are
higher on surfaces (like fallow paddocks) that
don’t capture the droplets as well.
In terms of weather factors:
• Midday turbulence—it’s normally recommended
to cease spraying before 11 a.m. in summer.
• High temperatures—avoid spraying at
temperatures above 28 degrees Celcius.
Depending on the crop and weather conditions there are many
new approaches being used to reduce spray drift. See below.
• Humidity—avoid spraying under low relative
humidity.
• Wind—avoid spraying under still conditions.
Light breezes are preferable.
• Inversions—avoid spraying when an inversion
exists—that is, when temperature increases
rather than decreases with altitude—the cold
blanket effect.
• Night spraying—high risk and should be
avoided.
Schematic showing the use of buffer zones to protect sensitive
areas from spray drift. Graphic modified from Conservation
Buffers: design guidelines – see page 3–11 for full citation.
What you can do
• Obtain and follow the best advice available, an
example of which is provided below. But, please
check with local authorities as well.
• Yet again, the value of buffer zones emerges
as a strategy to help prevent accidental drift
of herbicides or pesticides into sensitive
waterways.
The following is summarised or quoted directly
from the Noxious and environmental weed control
handbook—a guide to weed control in non-crop,
aquatic and bushland situations (NSW Department
Primary Industries, 5th edition, 2009), and in
particular pages 14-17 on “Reducing herbicide
drift” (Cook, T.).
Tips for how to be a Riversmart Farmer
• Real time weather data—this is needed on an
hourly basis, preferably recorded on your farm.
How to minimise spray drift
problems
Before spraying
• Always check for nearby sensitive areas such
as houses, schools, and riparian areas.
• Check for susceptible crops in the area, e.g. if
using a broadleaf herbicide check for broadleaf
crops such as grape vines, cotton, pulse or
vegetable crops.
• Notify neighbours of planned herbicide
treatments.
• Under the Pesticides Regulation 2009 of the
Pesticides Act 1999 it is essential that weather
and relevant spray details are recorded.
3–5
3. Reducing waterway pollution
Reducing spray drift
3. Reducing waterway pollution
During spraying
• Continuously monitor meteorological conditions
carefully and understand their effect on ‘drift
hazard’.
• Don’t spray if conditions are not suitable, and
stop spraying if conditions change and become
unsuitable.
• Record weather conditions (especially
temperature and relative humidity), wind speed
and direction, herbicide and water rates, and
operating details for each paddock.
• Supervise all spraying, even when a contractor
is employed. Provide a map marking the areas
to be sprayed, buffers to be observed, sensitive
crops and areas.
Minimising fertiliser and
chemical-rich run-off into
waterways
Since the massive algal bloom on the Darling
River in 1991 (see below) we’ve learned a lot about
what causes such blooms and how to combat
the problem. While Blue-green algae are found
naturally in our rivers, it is only under certain
circumstances that they can explode in numbers
to dominate. Depending on the type of algae
involved, and their toxicity, the threat to humans,
livestock and wildlife varies. But, it is safe to say
that when algal bloom blanket a waterway it’s best
to not allow exposure to these waters by people or
stock.
• Spray when temperatures are less than 28°C.
• Minimise spray release height (lowest possible
boom height).
• Use the largest droplets which will give
adequate spray coverage.
• Always use the least-volatile formulation of
herbicide available.
• Maintain a down-wind buffer which may be
in-crop e.g. keep a boom width from the
downwind edge of the field.
• If sensitive crops, pastures or environmental
situations are in the area, use a herbicide which
is the least damaging.
Algal bloom on the Darling River in 1991. Photograph: Daily
Telegraph.
Close-up view of an algal bloom. Photograph: Sarah Moles
Algal blooms have become more common over
recent years, especially during drought times
when river flows are greatly reduced. Combine this
factor with hot, windless days and lots of nutrientrich run-off, and you have all the ingredients for an
algal bloom.
3–6
Tips for how to be a Riversmart Farmer
Fundamentally, it’s about using the right fertiliser,
at the right time and in the right concentrations
or forms. These will all be determined by local
situations, the crop or pasture, the soil, existing
soil-water profile, proximity to watercourses and
groundwater, etc.
Most farming industries these days have
recommended codes of practice, BMP manuals
or ISO-accredited programs to help guide the use
of fertilisers and other chemicals, pesticides and
insecticides. In many states now there are also
programs like Fertilise Wise in Western Australia
which is an education, training and fertiliser
endorsement program (see Further reading for
a link to this site). For some industries, in some
states, nutrient and irrigation plans are required or
strongly encouraged.
Apart from managing the application of fertilisers,
chemicals, etc, there are also strategies now
employed to reduce run-off and spray drift (see
previous item) into sensitive environments. Buffer
zones (see Part 3) are a front line strategy—
whether they be grassed strips, more heavilywooded or a combination of both. In some
circumstances run-off is now directed through
on-farm natural or constructed wetlands to ‘polish’
the water (see Part 4) before it enters streams and
rivers.
The take home message is that unless smart
strategies are in place you’re potentially (a)
spending more than you should on fertilisers,
chemicals, etc, (b) probably not getting best bang
for your buck, and (c) contaminating the river and
helping to cause algal blooms or worse.
Tips for how to be a Riversmart Farmer
3. Reducing waterway pollution
A primary source of these nutrients (nitrogen
and phosphorus) are fertilisers and due to this,
considerable attention is now given to the science
of fertiliser use. Organisations such as CSIRO
have developed tools for farmers to help get the
best effect from fertiliser application while also
minimising the risks of contaminating nearby
waterways. CSIRO’s Farm Nutrient Loss Index
(FNLI) is one of the decision support tools available
to help farmers to assess the risk of nutrient loss
from the paddock. Factors it considers are surface
run-off, drainage past the root zone and lateral
flows through sub-surface soil layers.
Algal bloom. Photograph: Central West CMA
What you can do
• Review your farm-wide use of fertilisers,
chemicals, pesticides and insecticides to
ensure you’re getting best value for money and
also have the appropriate strategies in place
and working effectively to minimise your river
‘footprint’.
• Consider equipping yourself with a water quality
test kit so you can see what nutrients are in
your farm run-off and making their way into the
nearby creeks and river. This will also be very
instructive in terms of gauging the effectiveness
of your fertilisers application practices.
• Examine the following advice, drawn from the
Wetlands on Farms (2009) recommendations,
to see if you’re taking these steps.
Recommendations for good management
Manage nutrient levels
• Use fertilisers efficiently by monitoring soil
nutrient levels and crops carefully to find out
their specific nutrient requirements.
Reduce chemical use
• Apply integrated pest management strategies
to reduce chemical use. Use alternative control
measures rather than chemicals wherever
possible, such as competitive crops and
pastures or strategic grazing.
• Minimise the use of surfactants in herbicides
when near waterways. They are highly toxic to
many aquatic organisms, such as birds, frogs
and fish.
3–7
3. Reducing waterway pollution
• Choose the application method that minimises
the amount of chemical required and its
dispersal, guided by the label recommendations
for both quantities and application method. For
example, use wiping or injecting rather than
spraying.
Use chemical effectively and efficiently
• Only use the registered rate to achieve the
desired result and ensure spraying application
equipment is properly calibrated. Comply with
the directions on the container.
• Only use staff or contractors trained for safe
chemical use.
• Ensure that run-off from chemical treatment,
dip pump-out sites and septics cannot enter
waterways or wetlands via well grassed,
concrete or deep soil bunded areas.
Maintain buffer zones
• Maintain vegetated buffer zones around the
wetland/s and waterways.
Dealing with salinity
The problems of salinity are well known to the farming
community and don’t require a lecture on the subject
here. While salinisation impacts on farm production it
also has major impacts on river health if saline waters
infiltrate. Where the groundwater rises and is in direct
or occasional contact with the river bed, salinisation
can occur and this is a problem that needs regionwide approaches to see it fixed.
At the farm scale there are a range of measures
recommended to manage salinisation problems,
among them, increasing the areas of perennials or
strategically located plantings, to reduce watertable
recharge. The retention of native vegetation and
maximising water use efficiency when cropping are
other strategies recommended.
As noted in Part 4, about on-farm wetlands, if you
have a perched or rising water table there is the risk of
saline waters discharging into the wetland. In extreme
cases these wetlands end up being salt evaporation
basins.
Restrict treated livestock accessing the
wetland
• Restrict access to wetlands for livestock that
have received chemical treatment, whether
internal and external treatments, for at least the
recommended withholding period (Wetlands on
Farms, 2009).
Extreme case of creek bed salinisation. Note the dead trees –
symptomatic of the long term rising and highly saline water table.
Photograph: Bill Phillips.
What you can do
From the perspective of Riversmart farming the
following are important:
• Make sure you know and monitor water table
depths and salinity if you farm in areas with
problems of salinisation and a rising water table.
This will allow you to have the necessary measures
in place to manage the problem and reduce its
impact over time.
• If you have a situation like that shown in the photo,
seek expert help! It’s vital highly saline waters are
prevented from flowing into rivers—a slug of such
water can have devastating effects on river health,
fish and other aquatic life.
3–8
Tips for how to be a Riversmart Farmer
What you can do
In terms of water quality these are major concerns
and threaten all aquatic species for some
considerable distance downstream.
• Manage fuel loads through the use of tools
such as, controlled burning, short term or crash
grazing and keep weeds species under control
(see Part 6).
After a severe bushfire the first rains, if they
are heavy, can wash large volumes of ash and
sediment into a watercourse. Because there
are less trees and undergrowth, run-off can be
very high and soil erosion becomes a significant
problem.
As regrowth occurs along the watercourse this
will help stabilise the soil but it also requires more
water and so in the short-medium term the creek
or river may receive reduced run-off.
• Fundamentally manage your farm to reduce the
risk of wild fires, and be prepared in advance to
protect key assets, including (where possible)
buffer zones along watercourses, around
wetlands, etc.
• Work with your neighbours and local authorities
to combat fires and reduce risks at a regional
scale.
Depending on how hot the fire is, the impacts may
be minor through to catastrophic for wetlands,
especially those wetlands dominated by Red
gums. Fire may result in significant tree deaths for
example.
Fire is used as a management tool in many parts
of the country, as a way to either reduce bushfire
risk, for weed control, or both. Carefully managed
and appropriately timed fires can be very effective
tools.
In general, fire has no long term impacts on plants
like sedges, grasses and reeds. It can be quite
beneficial if an area is burnt infrequently with a wet
soil profile. Wetland canopy trees can be killed
by burning too frequently (Recommendations
for managing wetlands on farms in inland NSW,
2009).
Severly burnt watercourses can take years to recover fully.
Photograph: NSW DPI.
Fire impact on water quality following Victoria’s Black Saturday
fires. Photograph: Fern Hames.
Tips for how to be a Riversmart Farmer
3–9
3. Reducing waterway pollution
Fire, rivers and wetlands
3. Reducing waterway pollution
Black water events
Black water events happen naturally and occur
when storm or flood water carrying broken down
leaf litter, flooded crops and other vegetation end
up in a waterway where the tannins and lignin are
released. The water turns a very dark brown or
black colour, thus the name.
Waste management from the
homestead, workshop and
farm sheds
In the overall scheme of things it may seem
insignificant but accumulated across many
properties along a river system the wastes coming
from your home, farm sheds, workshops, shearing
sheds and shearers quarters etc can be quite
significant.
In days gone by it was a common sight to see
farm wastes (hard, as opposed to liquid or wet)
deposited in convenient depressions like creek
beds (see photo). Imagine the downstream
pollution this caused! Fortunately these days
farmers tend to dig pits they can cover over
once full. So long as these pits don’t intercept
groundwater they are probably the best option if
using Council tips is out of the question.
Murray cod kill due to blackwater on the Edwards-Wakool
system during the drought. Photograph: John Lollicato.
Black water events can also result in major fish
kills, especially the larger fish, due to very low
levels of dissolved oxygen. Apart from fish kills
this can also cause problems for species such as
crayfish, yabbies and shrimps.
And remember, scrap metal is worth money these
days – why not cash in rather than dump your
metal wastes.
The good news is that black water events are,
in the long term, good for our rivers as they
boost carbon levels and this helps energise
the food web, increasing the zooplankton and
macroinvertebrate communities, which in turn
provides more food for fish.
Black water events are most common when
there is a combination of rising air and water
temperatures and large volumes of organic matter
washed into the river.
What you can do
Very little can be done. These events are hard to
predict and the expert view is that while the loss
of the bigger fish that may occur is distressing and
seems difficult to accept, the long term impact of
black water events on river health is a positive one.
Be aware that during such events—it’s not open
slather in terms of removing fish. Best to check,
but in most States the normal fishing rules and
regulations apply irrespective.
3–10
Dumping waste like this is not very riversmart.
Photograph: Central West CMA.
Likewise, most farms today have septic tank
systems which are designed to minimise leakage
into watercourses although there is always the
risk of groundwater contamination. If you still have
older style systems for handling toilet wastes
and laundry-kitchen grey water etc it might be
wise to review how they operate and if they may
be a source of river contamination. Even well
treated sewage effluents flowing into rivers is very
dangerous from the bacteria perspective, and,
grey water, loaded up with detergents, is high in
nitrogen, phosphorus and salt (if you use powder
detergents) and helps fuel algal blooms.
Tips for how to be a Riversmart Farmer
3. Reducing waterway pollution
On-farm there is also the issue of how old
chemicals, pesticides etc are disposed of—see
above for further consideration of this.
What you can do
• Review the way your property handles all forms
of domestic and other hard and liquid wastes
to ensure these are not directly or indirectly
contaminating either your local waterway or
groundwater.
PLEASE SUPPORT THE
WORK OF RIVERSMART
Sources and further reading
Agricultural Council of Australia and New Zealand.
Standing Committee on Agriculture (1992) National
Guidelines for Beef Cattle Feedlots. CSIRO
Publications.
Central West Catchment Management Authority
(2008) Management and rehabilitation of riparian
lands. A best management practice guide for the
Central West.
Department of Environment and Conservation
NSW (2003) Use of Effluent by Irrigation. Sydney.
Fertilise Wise http://www.fertilisewise.com.au/
index.html
Indicators of Sustainability for Effluent Reuse in the
Intensive Livestock Industries: Piggeries and Cattle
Feedlots (a copy of the project report is available
from Australian Pork Limited, PO Box 148, Deakin
West ACT 2600 (Reference Number 1816).
Industry and Investment NSW (now the
Department of Primary Industries) (2009) Wetlands
on Farms.
NSW Agriculture (NSW Revised Edition 1997)
The New South Wales Feedlot Manual, The InterDepartmental Committee on Intensive Animal
Industries (Feedlot Section). Orange.
NSW Department Primary Industries, 5th edition
(2009) Noxious and environmental weed control
handbook—a guide to weed control in non-crop,
aquatic and bushland situations.
Stock and waterways: A manager’s guide. Land
and Water Australia, Staton, J. and O’Sullivan, J.
2006.
Tips for how to be a Riversmart Farmer
Riversmart Australia is a not-for-profit organisation with
the vision of “Managing rivers for people, wildlife and
sustainability”. What that means is we fund-raise, from a range
of sources, to make things like this Guide happen.
We started along the Macquarie River in 2008 with the goal
of getting people to ‘turn and face the river’ – that is, get out
and enjoy it, but also be prepared to help look after it – to
be a caretaker of sorts. Now we have our finger in many pies
from schools education, to landcare type restoration works in
collaboration with those who have the privilege of living on the
river or get out and enjoy it, scientific surveys so we know where
the problems are and all sorts of community events.
How can you help? Simple really…we need
financial support to keep doing what we do, so
please consider a donation to our (tax deductible)
Blue Bucket Fund.
In case you missed it, blue buckets are our trademark. Why? We
chose them because every household, school, business and farm
in this country has buckets. And what do they use them for –
moving water around… We hope that every time you use a
bucket (blue or otherwise) you’ll think about how much water you
really need, and if it’s not clean, what’s the best way to dispose of
it so it doesn’t end up in a nearby river.
If you’d like to know more about our work visit www.
riversmart.org.au or send an email to bill.phillips@
riversmart.org.au
We hope you’ll get behind this initiative.
3–11
4. Wetlands working for you
Wetlands can take many forms and from a
Riversmart farming view point all have benefits
that far outweigh any perceived costs. So, the first
question is: Do you have any wetlands, past or
present, on your farm?
What to look for? Low lying areas where water
will lie longer than elsewhere and where the plant
species that grow after regular wetting of the
area are the typical reeds, rushes and grasses
associated with wetlands, rivers and streams.
So effective are wetlands at cleansing water
that some farmers are using the same natural
‘technology’ and creating constructed wetlands.
Of course, some farm dams are classified as
wetlands—although barren turkey nest types that
are simply used for stock watering are not!
Reinstated farm wetland near Narromine. Photograph: Bill
Phillips.
What’s so good about wetlands?
This does depend on the type you have but in
general terms wetlands do the following:
• Help slow down, absorb and store floodwaters
• Reduce downstream water pollution by
capturing water-borne soil and other pollutants
such as nutrients that cause algal blooms
• As low lying areas they tend to be the last areas
to dry out during dryer times especially if they’re
surrounded by large trees and well shaded
Rehabilitating a wetland. Photograph: Chris McCulloch,
Central West CMA.
• They provide nice cool places for the family and
friends to relax on a hot afternoon
• Depending on how large the wetland you could
stock them with native fish and enjoy that
pastime
• They can provide for opportunities for carefully
managed grazing and cropping (see below)
• Help keep or bring a bit of nature back to your
property so that you get the benefits of species
that eat insects, pollinate plants etc.
On-farm wetland with healthy, grassed buffer zones and
stock exclusion fencing. Photograph: L Hughes, Water’s Edge
Consulting
Tips for how to be a Riversmart Farmer
4–1
4. Wetlands working for you
Managing your stock
Wetlands can provide shelter, shade and water
for stock but unless their access to the wetland
is regulated, cattle and sheep will quickly trash
it! They’ll do this by pugging and compacting the
soil, defecating and urinating in the water, bringing
weeds species into the area, over-grazing grasses
and other native species leaving the soil bare and
prone to erosion and weed invasion (See Part 1
for further information’).
While these are negative impacts, grazing can also
be used as a management tool for wetlands (and
river banks too if strictly controlled) to help with
controlling weeds, promoting native plant growth
and reducing fire risk.
Damage caused by unrestricted stock access. Photograph:
Bill Phillips
Keeping stock out of watercourses like this is highly
recommended to help improve downstream water quality.
Photograph: Bill Phillips
4–2
What you can do
• Fence stock out and provide drinking points
away from the wetland or alternatively restrict
shoreline access to a small area where you can
place rubble to reduce pugging and resultant
soil erosion. Don’t encourage your stock to
hang about the watering point at the wetland—
make it a sunny, hot spot!
• If grazing these areas to reduce weeds and fire
risk, ensure not to overgraze as this will invite
weeds back and accelerate erosion.
Fencing stock away from watercourses is a key management
step to improving river health. Photograph: Tim Gardiner,
Central West CMA.
Watering stock away from rivers is very riversmart. Photograph: NSW DPI.
Tips for how to be a Riversmart Farmer
Lever 1. Timing of grazing
• Grazing when native wetland plant species are
dormant reduces the impact on their growth
(wet versus dry times).
Lever 2. Duration of grazing
• Rest periods between grazing rotations allows
for the recovery of vegetation.
Lever 3. Intensity of grazing
Stocking rates
• Be conservative until you know what impacts
the grazing has on overall wetland condition
and resilience.
• Adjust stocking rates as necessary with
changing weather patterns, the seasons, etc.
• Rotate stock wisely—different breeds, ages
etc may graze differently so be alert to this
possibility.
The above kindly provided by Dr Rhonda Butcher,
Water’s Edge Consulting. See the end of this part
for the full citation.
• Appropriate stocking rates can minimise the
potential for creating compacted or pugged
areas, weed invasion, increased nutrients and
erosion
In general terms the following give some guidance
on grazing patterns. These will not suit every
situation but are given to assist with devising a
suitable grazing regime for your site.
For ecological gains the following general rules
can be applied.
Timing of grazing
Grazing should be avoided:
• Straight after water arrives in your wetland (after
a flood or heavy rainfall).
Overgrazing at right has exposed this area to erosion by water
and wind. Photograph: Tim Gardiner, Central West CMA.
• After fire when there is little to no vegetation
cover.
• When native plants are flowering, setting seed
and establishing.
• When the wetland is drying out, and the soils
are still wet—this will reduce pugging.
Duration of grazing
• Continuous grazing should be avoided
wherever possible.
• Intermittent grazing, interspersed with rest
periods, is preferred. Within seasonal or annual
periods, the longer the rest period the better.
Bare areas are also prime candidates for wind erosion.
Photograph: Tim Gardiner, Central West CMA.
• Intensive grazing over short periods (mob or
crash grazing) interspersed by lengthy rest
periods is commonly advocated.
Tips for how to be a Riversmart Farmer
4–3
4. Wetlands working for you
If grazing the wetland for fodder there are three
main considerations (management levers) as
follows:
4. Wetlands working for you
Cautious lake bed cropping
The cropping of floodplains and wetlands as
floodwaters recede, lake bed cropping as some
call it, is one opportunity some farmers take up.
Unless this practice is undertaken with care it
can have long term negative impacts on these
areas. It can disturb soil and cause compaction
due to the equipment used. It can also interfere
with the natural seed bank and invertebrate
eggs found in the soil that are so vital to wetland
ecosystems when they receive water. Weed
invasion is another possible consequence and the
application of fertilisers, herbicides and pesticides
can also impact on wetland functions and result in
pollutant-laden run-off into creeks and rivers.
Minimise the chances of erosion
• Choose crop and pasture rotations to maximize
groundcover.
• Use no-till practices. Retaining stubble can help
maintain ground cover and provide organic
matter for the soil.
• Use soil conservation earthworks where
appropriate, including graded banks and gullyfill.
Before considering lake bed cropping it is strongly
recommended that you consult with your local
agronomist, primary industries and catchment
management authorities. In some areas approvals
are required for this practice.
What you can do
The Wetlands on Farms booklet (NSW DPI 2009)
provides the following well considered advice.
Minimise the use of chemicals
• Use integrated pest and weed management
strategies to reduce reliance on chemical
control methods.
Lake bed cropping needs to be done with great caution with
various control measures adopted. Photograph: David Scadding.
It is also recommended you consult the ‘Guidelines
for managing cropping on lakes in the MurrayDarling Basin’ prepared by Sue Briggs and Kim
Jenkins in 1997.
Maintain buffers
• Maintain adequate buffer zones around your
crop and other vegetation. Buffers up to 100
metres wide are needed to protect the wetland,
for example, in the Western Division.
Allow for wildlife refuges
• Leave a section (up to 15 per cent) in the
middle of your lakebed uncropped as a wildlife
refuge and as a reference point to compare soil
conditions.
Do a trial run
• Undertake a trial in a small area of your lakebed
to test the feasibility of cropping and cultivation
practices before carrying out on a broader
scale.
• Develop a sustainable cropping plan.
4–4
Tips for how to be a Riversmart Farmer
Wetlands are so good at filtering water they can
be used to ‘treat’ effluents before they reach
rivers. ‘Chain of ponds’ type system (see photo
below) are now used quite commonly on farms
to trickle filter effluent, just as some sewage
treatment plants do.
Constructed chain of ponds wetlands system used to ‘polish’
run-off from a farm near Canberra. Photograph: Bill Phillips
Such use of wetlands shouldn’t be undertaken
without expert help as it’s not as simple as
connecting a series of dams along a creek lines
and planting reeds! Things like rates of flow
through, soil types, depth of the groundwater
table, types of plants etc can all impact on the
effectiveness of your reinstated or constructed
wetlands.
What you can do
• If you have a situation whereby your farming
operations generate some form of stock
or irrigation effluent (see Part 3 also) which
requires cleansing before discharge into a
river system, consider using constructed or
reinstated wetlands as part of the fix. In doing
this you may also gain lots of other benefits for
your farm and its bottom line.
Some of the risks
It needs to be said that while wetlands on farms
have many advantages and benefits there are some
potential risks.
For example, wetlands that sit stagnant and without
the right mix of fish, frogs etc species may encourage
mosquitos to breed. Getting the management of your
wetland right will reduce this risk, so if in doubt, make
sure to seek expert advice.
Wetlands are also prime breeding habitat for carp
and so if they get into the system you could see the
wetland dominated by them and this is not good for
the long term health of the wetland. In Part 5, carp are
considered in more detail.
Depending on the soil and underlying rock formations,
wetlands can sometimes be in direct contact with
groundwater, with water flowing back and forward
between them. Before considering installing a humanmade wetland or reinstating a former wetland it’s wise
to check the level of surrounding groundwater. This
is mainly because if the groundwater is highly saline
and flows up into your wetland this will turn it into an
evaporation basin and not much more.
Most wetlands of the inland have evolved, and are
adapted to Australia’s changeable weather patterns
meaning they thrive on being wet at times but not
constantly. Wetting and drying cycles keep most
types of wetlands healthy. However, if your farm has
a wetland that has been permanently inundated for
a long period, there is a risk that by re-introducing a
drying phase you could expose acid sulfate soils
(see photo below). If this is your situation seek advice
before you do the right thing by the wetland and give it
a dry phase.
But, please don’t be put off by this list of potential
risks. The benefits far outweigh them and your farm
will be better for having a wetland or two around.
Acid sulfate soils. Photograph: Murray Darling Wetlands Working
Group.
Tips for how to be a Riversmart Farmer
4–5
4. Wetlands working for you
Using wetlands to clean
potentially damaging run-off
or effluents
4. Wetlands working for you
Sources and further reading
Butcher, R. J. 2006. Sustainable grazing on
wetlands – healthy and grazing, how to have both.
On-farm breakfast series: Farming and Healthy
Wetlands. Published by Wimmera Catchment
Management Authority.
Briggs, S. and Jenkins, K. 1997. Guidelines for
managing cropping on lakes in the Murray-Darling
Basin.
Central West Catchment Management Authority.
October 2008. Wetlands Fact Sheet.
Industry and Investment NSW (now the
Department of Primary Industries) (2009) Wetlands
on Farms.
Land and Water Australia (2006) Managing instream wetlands on wool-producing farms. Land,
Water & Wool Fact Sheet.
NSW Department of Primary Industries (2009)
Guidelines for grazing in the Gwydir wetlands and
Macquarie Marshes.
Upper Murrumibidgee Catchment Coordinating
Group. Date unknown. Unearthing wetlands of
the upper Murrumbidgee. Topic 1: Fact Sheet for
Rural Landscapes.
Stock and waterways: A manager’s guide. Land
and Water Australia, Staton, J. and O’Sullivan, J.
2006.
4–6
Tips for how to be a Riversmart Farmer
5. Keeping feral pests under control
Sadly, Australia has seen many species
introduced, either by accident or for a specific
purpose, and several of these are now classified
as pests. While most farmers have witnessed first
hand the damage these species can do, in this
part of the guide we explain why trying to keep
these alien invaders in check is a good idea for
our waterways.
As was noted in Part 1 on Healthy riverbanks and
creek lines, anything we can do to reduce soil
erosion and help keep native vegetation along
creek and rivers will be good for their overall
condition.
Reducing the damage caused
by feral pigs, rabbits or goats
Feral pigs in particular are partial to wet areas
along rivers, creeks and in and around wetlands.
They wallow and dig up the soil making these
prime areas for soil erosion and invasion by weeds
species (see photos below and right). Feral pigs
can also carry diseases and destroy the nests of
ground-breeding or dwelling bird life.
Feral pig damage. Photograph: Michael Dickinson.
Rabbit warrens on slopes like this can also accelerate erosion.
Photograph: NSW DPI.
Feral pig damage. Photograph: Michael Dickinson.
Feral goats compete with sheep for pasture and
can also cause land degradation through soil
damage, overgrazing pasture plants and browsing
established trees and shrubs preventing their
regeneration. There is also a risk that feral goats
could be involved in outbreaks of exotic diseases,
such as foot and mouth disease, should such
diseases be introduced into Australia (Bureau of
Rural Science, 1995 Managing Vertebrate Pests:
Feral Goats).
Rabbit grazing can denude riparian slopes, stop
regrowth of ground plants and if their warrens
are in areas of high run-off the excavated soil can
accelerate sedimentation of nearby rivers and
streams (see photograph above).
Tips for how to be a Riversmart Farmer
What you can do
• Feral animal control is a routine part of farm
management and so little more needs to be
said here. Where infestations are so severe that
soil erosion and weed invasion are considered
serious then professional advice should be
sought on control methods and programs.
• Many organisations, such as Catchment
Management Authorities, offer farmers
incentives to help restore degraded areas
so consider approaching them to gain some
advice and possible financial assistance.
• Sometimes feral pest control gets better results
if several adjoining landholders join forces so
perhaps consider a broader scale of approach
depending on your situation. Consult the
relevant authorities for advice, such as in NSW,
the Livestock Health and Pest Authority.
5–1
5. Keeping feral pests under control
Doing something about
bloody carp!
Carp were first brought into Australia in the 1850s
and then became widespread after their release
from a fish farm into the Murray River near Mildura
in 1964. The spread of carp throughout the
Murray-Darling Basin coincided with widespread
flooding in the early 1970s, but carp were also
introduced to new localities, possibly through their
use as bait.
Carp are now the most abundant large freshwater
fish in the Murray-Darling Basin and are the
dominant species in many fish communities in
south-eastern Australia. A recent NSW Rivers
Survey found that carp represent more than 90
per cent of fish biomass in some rivers and have
reached densities of up to one fish per square
metre of water surface.
Carp like to breed in warm, shallow, reedy areas and in spring
seething masses like this are sometimes seen trying to get into
wetlands – a preferred breeding habitat. Photograph: Jonathan
McPhail.
Carp consume a range of small food items
such as molluscs, crustaceans, insect larvae,
seeds and sometimes plants. These are sucked
up (along with mud, aquatic plants and water)
from the bottom and along banks. This feeding
behaviour means they make water muddy (turbid
is the technical term) and this in turn impacts on
the growth of aquatic plants and the whole food
chain.
Carp rarely eat fish, but may consume fish eggs
and larvae and they disturb the breeding sites of
native fish. Adult carp have no natural predators.
Large predatory native fish, such as Murray cod
and Golden perch do eat juvenile carp, although it
seems they are not a preferred food item.
Carp breed from two to four years of age onwards
and spawning usually occurs in late spring or
early summer. Development is very rapid with
eggs usually hatching within two to six days. A
female carp may spawn several times in one
season, producing up to 1.5 million eggs per year,
depending on the size of the fish. Even though
fertilisation is close to 100 per cent successful,
there is, thankfully, a very high death rate of eggs
and larvae.
Top: Matt Hansen (Inland Waterways Rejuvenation
Association) with an adult carp on the Macquarie River.
Bottom: Lake Cargelligo during the drought—a carpet of dead
carp! Photograph: unknown.
5–2
Female carp go in search of warm, shallow, reedy
areas to breed in the spring. The males also
gather here and you sometimes see huge writhing
masses of carp in these locations (see photo
above). The eggs are laid onto the reeds.
Tips for how to be a Riversmart Farmer
• In the river—If you see large gatherings of carp
during the spring, when the females go looking
for breeding locations, report this to your local
fisheries agency or the Catchment Management
Authority. They may consider using some of
the latest technology, electro-fishing or nets to
reduce the population if it’s considered a ‘hot
spot’.
• On your place—If you have a wetland or farm
dam on your property carp will probably seek
this out as they like warm, shallow, reedy areas
for breeding. Things you can do include:
– You can try to limit their opportunities to
get into the wetland or dam using carp
exclusion mesh (see photo at right) on
culverts, channels or flow control structures
they’ll move through. You should seek expert
advice on how to go about this. Such mesh
excluders will only keep the adults out so
they aren’t an absolute fix to the problem.
– Another option is to net them at times when
they congregate (like spring for breeding) or
by training them to come to a specified area
or trap. You can do this by regular feeding
using chicken pellets for example. Be careful
here also as large carp are very heavy and a
lot of them thrashing around in a net will need
lots of humans or a tractor to extract them
from the water.
– Note that none of the above, other than
draining and drying out the wetland or dam,
will totally remove carp. If you try to reduce
their numbers with the other strategies it’s
a good idea to re-stock the waterbody with
species like Murray cod or Golden perch
that are known to eat young carp, when they
grow up a bit, of course.
New regulator at Yatco Lagoon with carp exclusion grates and
handles so they can to turned to help clean away debris that
accumulates. Photograph: Bill Phillips.
Carp trap being installed on the inlet of a floodplain wetland,
Banrock Station, SA. Photograph: Bill Phillips.
– Some landholders, usually with large
wetlands, invest in carp traps (see above).
Here also expert advice is needed. Carp
traps get more effective all the time but be
aware that if you go down this pathway you’ll
then have to manage and maintain the trap
and dispose of the dead fish once they are
despatched humanely.
– It goes without saying—but we will anyway
—under no circumstances use carp, or other
introduced fish species as live bait when
fishing. This is illegal for good reason.
– And, don’t let the kids ‘release’ their pet gold
fish into your dam or wetland. These can also
become established there and may even be
another strain of carp (koi for example) that
will cause more serious problems.
– Other alternatives are to drain the wetland
or dam, if you have a way to do so, and can
spare the water! If you do this, it would be
wise to look at ways to stop them re-infesting
the site, like exclusion mesh (see above right).
Tips for how to be a Riversmart Farmer
5–3
5. Keeping feral pests under control
What you can do
5. Keeping feral pests under control
What we know about Redfin
and Gambusia
Redfin were introduced into Australia from Europe
around 1862. They are an aggressive species
that have had a detrimental impact on native fish,
especially the less common small-bodied species.
You’ll find Gambusia in still and slow moving waters
such as wetlands, pools lakes, farm dams and
billabongs near the surface of the water and around
the waters edge. They can tolerate poor water quality,
and are often seen in small puddles and refuge holes
after most other species have gone.
Gambusia can have the following impacts on
waterways, wetlands and farm dams:
• They can attack and eat juvenile native fish,
waterbugs, frog eggs and tadpoles.
• They can nip at larger native fish causing fungal
infections.
Redfin—a voracious predator of native fish. Photograph: Matt
Hansen.
Redfin are voracious predators and consume a
wide variety of fish and invertebrates, including
small native fish species and the eggs and fry of
larger fish such as Silver perch, Golden perch
and Murray cod. They also carry a disease called
Epizootic Haematopoietic Necrosis (EHN) which
can be a serious threat to native fish.
Apart from trying to reduce their numbers by
draining a wetland or dam (as with carp) there
seems little else we can do about Redfin. While
they damage the habitat less than carp with these
in a confined space like a dam or wetland there’s
probably no point stocking it with native fish as the
Redfin will gobble them up!
Eastern Gambusia or Mosquito fish. Photograph: Gunther Schmida.
In the case of Gambusia, the Department of
Primary Industries’ Aquatic Conservation Action
Unit, in collaboration with the Central West CMA
has produced an information sheet entitled What
is Eastern gambusia?. The following information
has been drawn from that publication.
Gambusia were introduced into Australia in 1925
to help control mosquitoes. They are now widely
dispersed throughout Australia, in all States and
Territories. They are prolific breeders and ten adult
female fish can produce 5 million offspring in six
months.
5–4
• They compete with native fish for food.
• They’ve been implicated in the decline of at least
nine native fish species and more than ten frog
species.
It is illegal to sell Gambusia as a feeder fish outside
Metropolitan Sydney.
What you can do
• The drastic step of draining and drying out your
wetland or farm dam – and literally starting again
is about the most effective option available for
trying to combat these two pests. Even so, keeping
Gambusia out afterwards will be a challenge as they
seem to be able to get themselves transported to
almost anywhere there is water. Unlike carp, where
we know when and where they will congregate (see
previous section), Redfin and Gambusia don’t offer
such opportunities for control. Likewise, traps and
exclusion grates are pointless with Gambusia.
• Even so, the Victorian Department of Sustainability
and Environment has released a leaflet about how to
control Gambusia. It suggests that for waterbodies
that are connected to others only limited success
is likely. However, where the waterbody is isolated
from others repeated removal of Gambusia can
reduce their impact and even result in full removal
from that site. A key factor is the timing of removal
activities in the pre-spawning, winter-early spring
when water temperatures are less than 16 degrees
C and photoperiod (daylight hours) less than 12
hours. They note that a one-off removal will only
last a few weeks and that repeated removals are
needed, preferably monthly or less.
• Don’t transport or release Gambusia into any
waterways, dams, etc. And don’t use Redfin as live
bait for larger native species in our rivers. This is
illegal for obvious reasons.
Tips for how to be a Riversmart Farmer
5. Keeping feral pests under control
Sources and further reading
Aliens in the Basin. An introduction to alien fish in
the Murray-Darling Basin.
Bureau of Rural Science (1995) Managing
Vertebrate Pests: Feral Goats.
NSW Department of Primary Industries (2009)
Carp in Farm dams. Primefacts.
NSW Industry and Investment and Central West
Catchment Management Authority. What is
Eastern Gambusia? http://www.dpi.nsw.gov.
au/__data/assets/pdf_file/0009/384174/What-iseastern-gambusia.pdf.
Victorian Department of Sustainability and
Environment (2011) Guidelines form physical
removal of Eastern Gambusia. http://www.dse.
vic.gov.au/__data/assets/pdf_file/0006/120975/
Gambusia-removal-guidelines-2011.pdf.
Tips for how to be a Riversmart Farmer
5–5
6. Weed worries
There are a number of weeds that thrive along
rivers, on floodplains and in wetlands, creeks and
dams. A number of these have adaptations that
allow their seeds or plant fragments to be spread
via floodwaters, as well as by vehicles, machinery
and animals.
The riparian areas also harbour many paddock
weed species and are often a dumping ground
for discarded garden plants that become well
established and spread down the system.
For NSW farmers we strongly recommend
you get a copy of the publication Noxious and
environmental weed control handbook—a guide to
weed control in non-crop, aquatic and bushland
situations, produced by the Department Primary
Industries, as it provides important information you
need to take into account before launching into
weed control.
Willows – from a river health
perspective they are bad!
While there is some conjecture over the pros and
cons of using species like willows to stabilise and
recover eroded or degraded areas, from a river
ecology perspective the jury has delivered a clear
verdict—willows are bad!
However, it is true to say that some of the 100 or
so willow species found in Australia are worse, in
ecological terms, than others. At one end of the
‘invasiveness’ spectrum are Weeping Willows and
at the other end are the so-called nasty species
like Black, Tortured, Basket, Golden Upright and
Crack Willows.
In this section we’ve chosen to focus on only a few
of the greatest threats to rivers, floodplains and
wetlands, but there are others you should take into
account—and some of these summarised at the
end of this part.
Willows grow out into waterways collecting sediment and
debris and blocking access. Photographs: Central West CMA.
The Federal Government has declared all willow
species as Weeds of National Significance except
for Weeping, Pussy and Sterile pussy willows.
The Molonglo River near Canberra—slowly being choked
by invading willows and other woody weeds. Photograph:
Bill Phillips.
Willows choke up waterways collecting sediment and debris
and affect the path of flood waters. Photograph: Central West
CMA.
Tips for how to be a Riversmart Farmer
6–1
6. Weed worries
From a river ecology perspective some of the
problems willows pose are as follows:
• “The ability of some willows to colonise and
obstruct waterways, diverting flows into banks
or outside the main watercourse causing
erosion and sedimentation.
• Their ability to spread aggressively and displace
native vegetation leading to a monoculture
of willows in many places. This results in
ecological changes and reduced habitat
diversity (their bark and structure isn’t as varied
as native species like Eucalypts), thereby
reducing critical components of the food web
such as insects and other wildlife.
• Their leaves are dropped into the water all at
once, which can starve the water of oxygen
and kill many species of insects and fish. In
contrast, native vegetation sheds vegetative
matter continually across all seasons providing
an ongoing food source.
What you can do
• Willow and other woody weed control is a high
priority for many government funding programs,
especially for Weeds of National Significance
(like willows). So, you could seek advice on how
to access this type of support, if you wish.
• Where large infestations of willows (and other
woody weeds) are being controlled, clear felling
is not the recommended approach as this may
expose areas to serious soil erosion. Consult
your local CMA or relevant government agency
for advice on taking a staged approach. There
are also other means to controlling certain
woody weeds like stem injection.
• With a staged removal of willows, this should
go hand-in-hand with staged reintroduction
of native species to ensure the river banks are
stabilised throughout the process.
• Their ability to reduce open water by
successfully trapping sediment which reduces
water depth and enables willows to colonise
new areas.
• Willows can shade out understorey plants
such as shrubs, grasses and sedges, reducing
diversity and habitat.
• Willows reduce water flow, sometimes causing
stagnation and toxic algal blooms.” (Greening
Australia’s Willow Management Plan for Lake
Burley Griffin, 2006)
Recent research has measured the volumes of
water in-stream willows consume.
It concluded that removing in-stream willows
may potentially save 5.5 megalitres per year per
hectare of willow crown projected canopy area as
well as promote improved stream flow and water
quality.
This means that one hectare of in-stream willows
with permanent access to stream water consumes
an average of 20 megalitres of water per year.
You do the sums and work out how much more
water your willows are using than environmentallypreferable native species.
Most willows, by their very nature invade
watercourses, and spread rapidly. Another impact
of this is the lost opportunities for gaining access
to the river for recreational activities, such as
fishing, swimming, canoeing, etc.
6–2
Willow removal program on the Molong Creek by the Central
West CMA. Photograph: Central West CMA.
Tips for how to be a Riversmart Farmer
The following information is drawn from the
publication Lippia (Phyla canescens) management:
Challenges, opportunities and strategies (National
Lippia Working Group 2008).
Lippia (Phyla canescens) was introduced into
Australia in the 1920s as a ground cover. The plant
is tenacious and has many survival adaptations
and can now be found in all states and territories
of Australia. It particularly colonises riparian and
wetland areas, and any watercourse that stays
damp long enough for it to establish. Once lippia
has become established it is virtually impossible to
eradicate, however recent studies have indicated
that it can be controlled by using grasses as a
competitor.
From the ecological perspective some of the
problems lippia poses are as follows:
• Lippia successfully out-competes desirable
native riparian and wetland species.
• Lippia will establish in areas which have been
heavily disturbed and this includes areas where
cattle graze along river edges and in wetlands.
• The plants adaptations include its ability to
grow from fragments broken off stems, and its
capacity to seed prolifically.
• A major environmental impact of lippia is that it
causes massive slumping and erosion of creek
and river banks.
• As with many weeds, lippia forms a thick
impenetrable carpet, which spreads over large
areas, forming a monoculture and thereby
reducing biodiversity.
• Water flow, domestic and native animals,
vehicles and machinery all contribute to the
spread of lippia.
• Climate change could assist the spread of lippia
due to the potential for an increase in extreme
rainfall and flood events.
What you can do
• If there is good groundcover present, conditions
are generally unfavourable for the survival of
lippia recruits, both from seed and fragments.
Thirty per cent lippia cover is a major problem
if the other 70 per cent is bare ground. But,
30 per cent lippia cover is not a big problem if
the other 70 per cent is productive perennial
pasture or a native assemblage including
groundcover, shrubs and trees.
Lippia forms a carpet across the ground.
Tips for how to be a Riversmart Farmer
6–3
6. Weed worries
Lippia crippling our
floodplains and watercourses
6. Weed worries
• Mechanical control
Short-term control of lippia can be achieved
where infestations are ploughed or harrowed.
This method is not practical if lippia is growing
in riparian zones (such as creek banks) due to
the high risk of erosion and soil loss.
Lippia is not usually a problem in cropping
areas as it can be readily ploughed into the soil.
However, machinery easily spreads lippia, so
it is recommended that machinery working in
lippia-infested areas is washed down before
leaving the infested area.
When lippia is actively growing and soil moisture
levels are good, herbicide can be used in
conjunction with mechanical control to give
better results.
• Herbicide control
Lippia infestations. Photographs: Above: Bill Phillips.
Below: GHD.
As lippia is a broadleaf weed that occurs
in pasture situations, some herbicides can
be used to reduce lippia without harming
competitive grasses.
There are limited herbicides registered for use
on lippia, but there is no herbicide currently
available that will effectively suppress the
growth of lippia in the long term. Due to its
ability to rapidly recover and spread, multiple
herbicide applications within a season have
been shown to give better lippia suppression
than single applications. However, chemical
control can become very costly in areas that
have heavy lippia infestations.
Chemical control is not suitable in riparian areas
due to the risk of polluting waterways. Also,
herbicides should not be applied immediately
after rain or if heavy rain is forecast.
Before using any herbicide always read the
directions on the label carefully and use strictly
as directed.
• Experience has shown that using just one form
of control is less likely to work and that efforts
made have to be for the long term – no quick
fix here sadly. The following is taken from the
fact sheet: Lippia, Condamine couch/curse
(Queensland Department of Primary Industries,
2009).
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Tips for how to be a Riversmart Farmer
6. Weed worries
Alligator weed – it might only
be a matter of time!
While Alligator weed will grow on land it is also a
major threat to waterways, and if left unchecked
completely overgrows and chokes them (see
photos).
Of major concern is (a) the potential for Alligator
weed to spread via fragments throughout our
inland river systems and (b) that it is resistant to
herbicides.
From a farming perspective Alligator weed
seriously threatens irrigation-based industries
in particular. It can also dominate pasture areas
and stock that eat it can suffer (malnutrition, if
consumed in large amounts) and photosensitivityrelated problems.
While it is most commonly a problem for coastal
areas, more and more outbreaks are being
reported further inland so farmers in particular
need to be vigilant and immediately report any
sightings. An outbreak of Alligator weed has
recently been found near Mudgee in NSW.
Alligator weed infestation can choke the life out of your
waterway if it gets a hold. But, control is possible as shown
in the before and after photographs above. Be vigilant and if
you see this plant call your local weeds officer or department
ASAP. Photographs: NSW Department of Primary Industries.
What you can do
Alligator weed.
• Be aware of the ways Alligator weed can end
up on your place (for example, via irrigation
water, fragments in stock hooves, vehicles
or machinery, contaminated feed, turf etc or
floodwaters) and take the recommended steps
to reduce these risks. Get your copy of ‘An early
detection guide for farmers’.
• Be vigilant and look for any signs of this nasty
weed on your property or anywhere you see it,
especially after flood events.
• Don’t attempt to control or remove it yourself,
contact your local weeds officer or organisation
ASAP. They will then help activate the steps
needed to proceed.
Alligator weed infestation encroaching on the surface of a
waterway. Photograph: NSW Department of Primary Industries.
Tips for how to be a Riversmart Farmer
6–5
6. Weed worries
Salvinia – pray it doesn’t
come near you!
A bit like Alligator weed, Salvinia is considered one
of the nastier aquatic weeds—in fact some people
consider it one of the World’s worst weeds!
In contrast to Alligator weed, Salvinia is a freefloating fern which forms very thick mats that
eventually cover the entire surface area choking
the life out of system as light is cut-off and all the
species under the mat either have to move away
or perish.
Salvinia is currently found mostly in coastal
locations but inland sightings have been recorded,
so be alert—you don’t want this on or near your
farm. Apart from destroying ecosystems it also
blocks irrigation pumps and channels and denies
us opportunities to fish, swim and enjoy our rivers
and wetlands.
Of major concern is how hardy Salvinia is. It
spreads itself via buds or rhizomes and these
can survive and become established in a wide
range of environments and water types. It’s
been reported that Salvinia can survive on mud
for up to 12 months and even regenerate after
drought, extreme heat or frosts (Management
and Rehabilitation of Riparian Lands BMP for the
Central West).
While there are a range of control options available
it is recommended you seek expert help—Salvinia
is a major, major concern and not to be dealt with
by landholders on their own.
6–6
Top: Salvinia up close. Bottom: Salvinia infestation on the
Magela floodplain in Kakadu National Park. Photographs: Max
Finlayson.
What you can do
• Be aware of what Salvinia looks like, be vigilant
and look for any signs of it in your wetlands or
nearby streams and rivers.
• Don’t attempt to control or remove it yourself—
contact your local weeds officer or organisation
as soon as possible. They will then help activate
the steps needed to proceed.
Tips for how to be a Riversmart Farmer
6. Weed worries
Other weeds to worry about
Sadly there’s a very long list of other weed species
that are spreading and impacting on farming lands
and the adjoining rivers, streams and wetlands—in
fact too many to consider all of them here. Some
of the more prominent ones are as follows:
Noogoora Burr, Bathurst Burr, Castoral Oil Plant
(see photo below), African Boxthorn, Blackberry,
Green Cestrum and Coolatai Grass.
Green Cestrum: Photograph: Ashley Bullock.
(www.westernweeds.org.au)
Castor oil plant can growth higher than a car if not dealt with
early. Photograph: Bill Phillips.
African Boxthorn: Photograph: Ashley Bullock.
(www.westernweeds.org.au)
Other weeds, which locally may be more serious
are: alisma, arrowhead, blue water speedwell,
celery buttercup, creeping buttercup, dense
waterweed, elodea, hygrophila, ludwigia, parrots
feather, reed sweetgrass, sagittaria, Senegal
tea, spiny rush, torpedo grass, watercress,
water hyacinth, water lettuce, water poppy and
yellow waterlily (Recommendations for managing
wetlands on farms in inland NSW, 2009).
Noogoora Burr. Photograph: Lucas Hayes.
(www.westernweeds.org.au)
Tips for how to be a Riversmart Farmer
It should also be noted that there are situations
where native species from other parts of the
country have become established outside their
normal range and are now becoming ‘weeds’
in every sense. In the central west of NSW for
example white cedar is a case in point and you
should speak to the Catchment Management
Authority about removal of this species. It is in the
process of being listed as a “feral native species”
and will soon be able to be removed.
6–7
6. Weed worries
Sources and further reading
Central West CMA (2008) Management and
rehabilitation of riparian lands: a best management
practice guide for the Central West.
Central West CMA (2009) Lippia Management in
the Macquarie Marshes and Gwydir Wetlands.
Greening Australia (2006) Lake Burley Griffin
Willow Management Plan, Molonglo Catchment
Group.
National Lippia Working Group (2008) Lippia
Management: Challenges, opportunities and
strategies.
Water Lettuce. Photograph:
Don Mackenzie
(www.westernweeds.org.au)
What you can do
• The best thing to do is get your hands on one
of the many guides for weeds species in your
area, keep your eyes open and then report any
suspected outbreak or occurrences of these
species to relevant authorities.
NSW Department Primary Industries, 5th edition
(2009) Noxious and environmental weed control
handbook—a guide to weed control in non-crop,
aquatic and bushland situations.
NSW Department of Primary Industries and
others. Alligator weed. An early detection guide for
farmers.
Glove Box Guide to Plants of the Gwydir Wetlands
and Macquarie Marshes.
McCosker R.O. (1994) Lippia (Phyla nodiflora). An
Invasive Plant of Floodplain Ecosystems in the
Murray-Darling Basin.
Queensland Department of Primary Industries
(2009) Lippia, Condamine couch/curse. Fact
sheet.
Quantifying water savings from willow removal
in Australian streams, Tanya Doody and Richard
Benyon Summary here http://www.csiro.au/
science/Removing-Willows-Saves-Water.html
6–8
Tips for how to be a Riversmart Farmer