Irrigation

Water resources on-farm have to be managed in an integrated manner; irrigation, drainage and groundwater are major components of the farm water balance.

Well-designed irrigation/drainage layouts maximise production per megalitre of water applied, increasing profits, as well as saving you time and water. Potential deep drainage and surface run-off losses are minimised, reducing the contribution to waterlogging, salinity and reduced water quality

What you gain and what it costs

BENEFITS

COSTS

Provide the right amount of water at the right time to meet pasture and crop requirements.
Optimise water use, increasing productivity per megalitre.
Achieve even watering of paddocks.
Save time by faster waterings and/or automation of irrigation.
Reduce labour inputs, giving you more time to manage other aspects of your farm business.
Minimise deep drainage, reducing the risk of salinity and loss of nutrients.
Minimise surface run-off, reducing the loss of nutrients from the farm to water courses.
Regular maintenance will ensure the equipment and infrastructure remains effective.
Adequate drainage will help to minimise waterlogging, which would otherwise reduce pasture yields and contribute to soil degradation
and leakage into the groundwater (salinity).

Some pressurised systems have a high initial capital cost (centre pivots, fixed sprays, etc.) but require minimal earth movement.
Laser grading for flood irrigation layouts is expensive when large volumes of soil have to be shifted.
Time and costs are associated with obtaining new management skills.
Consider the additional costs involved if the system requires updating (e.g. soil moisture monitoring, irrigation automation, etc).

At work on the farm

Ross and Keith Nicoll, Numurkah

Pasture utilisation increases with the more efficient use of irrigation water.

Brothers Ross and Keith Nicoll have improved the border check irrigation system on their property in the northern irrigation region of Victoria.

Initially, they developed a whole farm plan with help from the Department of Primary Industries’ environmental team and irrigation designers. The plan included:

automation of the irrigation system across 300 hectares of the property; and
a reuse system to capture run-off from irrigation and rainfall.

Automation means water is applied efficiently. Larger volumes are applied for shorter periods of time, wetting the pasture root zone and keeping recharge and run-off to a minimum.

The Nicolls also focused on pasture management to increase water use efficiency. This includes applying fertiliser and grazing on a rotation that best suits the pasture species.

Installation of the automated irrigation system has reduced the volume of irrigation water running off.

As well, the construction of a reuse dam ensures that valuable water and nutrients do not leave the farm as run-off.

Water use efficiency on the Nicolls farm has doubled. Pasture utilisation has increased from nine to 16 tonnes of dry matter per hectare (tDM/ha). This increase in home-grown feed has been a key profit driver.

“By increasing the amount produced from irrigation water, we are using the water in a more sustainable manner. This has also benefited the business’s bottom line,” Ross said.

Do any of these look familiar?

UNACCEPTABLE PRACTICE

ACCEPTABLE PRACTICE

ABOVE ACCEPTABLE PRACTICE

Channel infrastructure poorly constructed and maintained.

Farm channels and bay outlets are well designed, constructed and maintained.

Farm water supply system is fully automated.

Scheduling based solely on routine; no consideration of climatic conditions (evaporation, rainfall), plant requirements and soil water content.

Incorporate local rainfall information in irrigation scheduling decisions.

Using monitoring equipment, such as gypsum blocks, for soil water measurement allows for accurate irrigation scheduling.

What you need to know (Victoria only)

Legislation needs to include federal legislation for Murray Darling Basin regions.

Environmental Protection Act 1970 administered by Environment Protection Authority (EPA). Under this Act, the Waters of Victoria Policy (SEPP) has specific requirements for irrigation channels and drains. These must be designed and managed so that their waters are not harmful to humans or have unacceptable impacts on animals, and so that the impact of their flow, sediments, nutrients, salt and other pollutants on surface and groundwater resources is minimised (www.epa.vic.gov.au/about_us/legislation/)
Re-use water - No licence is needed for water that is re-used and collected in a dam that meets certain requirements. The Department of Primary Industries (DPI) can provide specifications for re-use dam design.
Dairy company quality assurance - Some dairy companies have requirements for water use efficiency and water leaving the property. Check to insure compliance!
T he DPI, the Department of Sustainability and Environment (DSE), Environment Protection Authority, Catchment Management Authorities (CMAs), relevant water authorities and industry sectors, including farmers, are encouraged to work together to minimise the pollutants entering irrigation drains.
CMAs and water authorities have regional plans and strategies to manage the impact of irrigation on the environment. Farmers should ensure that their operation is consistent with these plans.
Licences - A Water Use Licence is required to use water for irrigation. For groundwater this is called a Groundwater Licence, for surface run-off water a Diversion Licence. You must comply with the requirements of your water licences - to check these requirements and review your licence conditions, contact Goulburn-Murray Water.
Local councils - Permits may be required for new works on the property, including clearing remnant vegetation. Check with your local council.

Water management at all levels is governed by legislation and regulation. The general area is quite complex and the numerous Acts and Regulations can be very detailed. In addition, changes to the legislation are made on a regular basis. The precise effect in a given situation will require expert advice and this should be sought from an appropriate professional or the relevant Government agency. Non-compliance can result in prosecution and/or fines!

Additional information

These resources can help you develop your Action Plan (Organisations, their contact details and website information were correct at the time of publication. Information may change without notice).

Organisation	Information Available	Internet
Victorian Department of Primary Industries	DPI Irrigation System Selection and Design Guidelines - a web-based information system that guides you through the decision-making process. Covers surface irrigation and pressurised irrigation systems.	www.dpi.vic.gov.au > Agriculture > Soil & Water > Irrigation
Dairying for Tomorrow	Effluent and Manure Management Database for the Australian Dairy Industry	www.dairyingfortomorrow.com > Tools & Guidelines
Dairy Australia and DairySA	Water in the Dairy; Dairy Industry Info Sheet no. 10 South Australia	www.dairyingfortomorrow.com > On-farm Action > Tackling Specific Issues > Water
Goulburn-Murray Water	G-MW Farm Exploratory Drilling Scheme FEDS	www.g-mwater.com.au/environment /salinity /groundwaterpumpingincentives /feds.html