Water monitoring and planning in agriculture

What water monitoring involves

Monitoring water availability is about more than just calculating how long your supply will last.

Water monitoring includes:

• tracking dam levels - use measuring sticks or visual markers to check water depth and surface area. This helps estimate volume and detect losses over time.
• recording rainfall - keep a rain gauge on-site and compare readings with local weather data. This helps assess runoff potential and recharge rates.
• observing runoff and erosion - after heavy rain, inspect paddocks, drains and dams for signs of erosion or poor water capture.
• checking infrastructure - inspect pipes, tanks, pumps and troughs for leaks, blockages or wear. Even small faults can lead to significant losses.
• monitoring evaporation - open dams can lose up to 50% of their volume in summer. Consider shade, depth and vegetation to reduce losses.

These observations help you respond quickly to changes, plan maintenance, and make better decisions about water use.

Water monitoring and planning checklist

1. Dam and tank monitoring

• Measure dam depth and surface area to estimate volume
• Record dam levels weekly or after major rainfall events
• Check for signs of seepage, erosion or wall slumping
• Inspect spillways for blockages or vegetation loss
• Monitor tank levels and check for leaks or overflow

2. Rainfall and runoff

• Install and maintain a rain gauge on-site
• Record daily rainfall and compare with historical averages
• Observe runoff patterns after rain — check for erosion or poor drainage
• Assess whether rainfall is effectively recharging dams or tanks

3. Infrastructure condition

• Inspect pumps, pipes, valves and troughs for leaks or wear
• Check solar or electric pump systems for reliability
• Clean filters and screens regularly
• Ensure overflow systems are working properly

4. Water quality

• Test water for salinity, pH, turbidity and algae
• Sample from multiple points if using more than one source
• Record test results and note seasonal changes
• Take action if water is unsuitable for livestock or irrigation

5. Soil moisture (if irrigating or managing pasture)

• Use soil moisture probes or manual checks to assess moisture levels
• Monitor at multiple depths (for example, 10 cm, 30 cm, 60 cm)
• Use moisture data to guide irrigation timing and pasture rotation
• Review soil temperature and rainfall alongside moisture readings

6. Water budgeting and planning

• List all water sources and estimate current volumes
• Calculate daily demand for stock, crops and domestic use
• Estimate losses from evaporation, seepage and fouling
• Forecast how long water will last under current conditions
• Develop a plan for dry periods (for example, destocking, alternative sources)
• Review and update your water budget monthly or seasonally

7. Seasonal preparation

• Before summer: check dam levels, evaporation risk, pump seals
• Before winter: inspect runoff areas, plan desilting or dam repairs
• After major weather events: reassess water supply and infrastructure.

Using a water budget

A water budget is a tool that brings all your monitoring together. It estimates how much water you have, how long it will last, and what actions you need to take. It includes:

• all water sources: dams, tanks, bores, rainfall
• daily and seasonal demand: livestock, irrigation, domestic use
• losses: evaporation, seepage, runoff, fouling.

You don’t need complex tools to get started. Estimating dam volume, tracking rainfall, and recording daily usage are simple but effective steps. Planning ahead helps you:

• identify shortfalls early
• decide when to destock or consolidate watering points
• prioritise water use during dry periods
• explore infrastructure upgrades or alternative sources.

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Video transcript

Farm Water Series - Budget

[Music]
it's really important that land holds do
budget their water there is a lot of
talk about budgeting for feed well
really it's the same thing in fact water
is really more important because you
can't utilise the feed without having
sufficient good water so you need to do
a budget the broad idea is to
estimate how much consumption the stock
on your farm are going to need and you
need to do it to the maximum capacity
not to what you've currently got what
you can run as a maximum
and you need to to estimate what they
will use and then you need to be sure
that you're able to deliver that
if you can't you know you've got a
problem i think the drought hopefully
has taught some some lessons and the
best thing to do is now sit down with a
cool head do budgeting do the designs
and be ready for the next one
with some broad rules of thumb you can
calculate what your stock water use will
be
you need to have not just the flow rate
but you need to have the capacity to
supply what the stock need if something
goes wrong with your water supply
so you need to have a tank that's going
to be able to supply that amount of
water they need and normally for a few
days in reserve
if you're using dams we also need to
take into account natural losses
evaporation is a much bigger loss than
most people think so we need to
realistically factor in those you never
get it absolutely right but you need to
make a reasonable estimate of each of
those factors so you can make sure your
stock have the water they need
in the heat of drought and the heat of
summer even not in a drought time
evaporation can be very significant it
can use up to 40 percent of the water in
dam
just in a normal summer so you need to
monitor the situation particularly in a
drought how much stock have i got how
much water are they using and
do i have enough in the storage to be
able to supply what they need and if you
can see that you haven't you can take
action before disaster happens
in terms of estimating the remaining
supply if you've got a header tank you
can normally use all the water that's
available to you if you've got a dam
sometimes you can't get the last bit so
it might be holding water a certain
volume but you might not be able to
access that last bit so you are you have
to be careful that you're estimating
realistically how much you've got left
this one can run up to 250 head of
cattle and so it's got a demand when you
calculate that up of about 11 000 liters
per day if you're 250 head of stock
there is a tank on this farm which holds
about 95 000 liters the supply from the
pump
can be
in the order of about 14 000 liters a
day if it pumped all day so it's got
ample to supply
the rate of use as well
so this farm is actually very well set
up to cater for the demand the budgeting
has been done well and it's got plenty
in reserve
seepage in urban dams is usually a lot
more than people realise
because the water's just seeping into
the ground and you never see it a good
dam might uh have seepage of about one
millimeter per day of depth
an acceptable maximum would be about
five millimeters per day
once you start getting above that and
there are losses above that you really
need to do something about your dam put
some ceiling in improve the dam find out
where the leaks are
the stories of farmers who have been in
distress in the middle of a drought when
everything is down and when they see
their stock suffering is appalling and
that's heartbreaking and people get very
depressed and and wonder how can they
come back from this
the water is so critical the budgeting
is important for first getting the
system right and then also managing it
properly in one sense you can describe
it as a little bit as a financial budget
if you've got you've got to get it right
to start with and you've got to keep on
top of it or same with water
you

Seasonal planning

Water monitoring is especially important during seasonal transitions. Before summer, check:

• dam levels and evaporation risk
• infrastructure condition (for example, pump seals, pipe joints)
• water quality
• backup sources in case of failure or contamination
• during winter, monitor runoff and erosion, and plan for desilting or dam repairs while water levels are low.

Managing water runoff after rain events

Rainfall can dramatically affect water quality, especially after long dry spells.

When rain hits bare or compacted ground, it often carries soil, organic debris, and contaminants into dams, tanks, or waterways.

To protect water quality and reduce erosion, landholders can take proactive steps immediately after rain:

1. Skim surface debris early
   Within 24–48 hours of a rain event, remove floating organic matter like leaves, grass, or animal waste before it sinks and begins to decompose. This helps prevent foul odours and taste issues.
2. Monitor water clarity
   Cloudiness may result from clay particles, organic matter, or suspended solids. Observe whether the water clears naturally or needs treatment, especially if it's used for livestock.
3. Improve groundcover
   Strengthening vegetation in catchment areas helps slow runoff, trap sediment, and reduce erosion. Grasses and pasture species act as natural filters.
4. Use sediment screens and swales
   Strategically placed barriers across slopes or drainage lines can intercept debris before it reaches water storage areas.
5. Fence off sensitive zones
   Temporary fencing around catchments allows vegetation to recover from grazing pressure and stabilizes soil.

These simple actions can significantly improve water quality and ensure your water sources remain safe and productive for future use.