Community
17 January, 2025
Farmers urged to think before digging dams
SEASONAL conditions have led to a shortage of stock water across most of Victoria which has renewed interest in constructing farm dams, and the addition of pumps, bores, tanks, troughs and piping.
Agriculture Victoria land management extension officer Clem Sturmfels advised farmers to ask important questions before digging a new dam or adding water infrastructure to their property.
“Before engaging an earthmoving contractor for a new dam, investigate answers to important questions like: How much water do I need, will the dam hold water, will it fill most years, how big should it be, is there a good site for a spillway, do I need a permit or license, what will it cost?” he said.
“Longer, hotter summers and decreased cool season rainfall has meant many smaller dams built in previous years are drying up - lack of runoff, increased water consumption and evaporation contribute to this issue.
“Many new dams built across Victoria are also failing within the first few years due to inappropriate materials or poor construction techniques.
“As a result, farmers need a bigger catchment area to improve the chances of filling dams regularly.
“At least 10 hectares of catchment for every megalitre of water stored in a dam is recommended - runoff from nearby roads and tracks is an effective way of getting water, especially in a dry year.”
Mr Sturmfels said there were a number of factors to consider when building a livestock dam.
“A livestock dam should be as deep as your site will allow and have a minimal surface area to reduce evaporation - consideration should be given to planning a key large dam to use for reticulating water to troughs across the property, via gravity or pumps,” he said.
“Allow a minimum spillway width of 5m - the spillway should end with a level spreader to ensure water leaves the dam in a thin wide sheet.
“A gently sloping, well grassed area is essential for a safe and stable spillway. The spillway should have little or no slope with a flat cross-section.
“The addition of a trickle flow pipe set below the spillway level will minimise ongoing maintenance.
“Purchasing appropriately sized pumps, tanks, troughs and pipes is essential for providing the flow of water needed on a hot day.”
Mr Sturmfels also recommended farmers ensure troughs are protected from livestock damage while being easy to maintain.
“A single inferior fitting in a farm pipeline could result in total system failure and loss of valuable water,” he said.
“Reputable products will be marked with the manufacturer’s details, date of manufacture, a relevant description and appropriate industry markings.
“For example, the markings on good quality rural polyethylene pipe will include PE80 or PE100, indicating the long-term strength of the materials.
“When purchasing pipeline equipment and fittings, deal with a reputable supplier with a good track record, spare parts and after-sales service.
“Selecting an experienced and reliable contractor, plus a few basic soil tests, will minimise the risk of failure.”
A permit or license may be required to build, extend or repair a farm dam in Victoria – farmers are encouraged to contact their local rural water authority before commencing works.
For further information, visit the Agriculture Victoria website.
As part of the Victorian Government’s $13.53 million drought support package, eligible south west farmers can apply for on-farm drought infrastructure grants of up to $5000 to upgrade farm water systems.
Further information, including how to apply, can be found at ruralfinance.com.au.
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