Dairy Water Supply

A typical dairy farm uses a lot of water, so it is important that farmers implement effective measures to protect this valuable resource and consider all available water sources and supplies.

Alternative water supplies

A back-up supply of water from a bore can be widely used farm. It can be used to supply yard wash water directly or mixed with re-used yard wash water destined for disposal. In many areas, the temperature of bore water is constant throughout the year (usually 16 to 18 degrees Celsius), meaning bore water can be used to supply the pre-cooler too.

Licensing from the water authority is generally required to construct a bore and then use it to supply water for dairy wash down. You can save money by using bore water to fill the header tank on off-peak power or via a windmill.

Divert and use rainwater

The dairy yard can catch a huge amount of rainwater. You can calculate how much has fallen over the course of the year by multiplying the annual rainfall in millimetres by the area of the yard in square metres. Using diverters in the dairy yard enables this water to be captured for future use by storing or pumping before it enters the effluent system.

This system means the waterflow is intercepted between the yard and sump. Diverters, which come in metal bridge or valve types, are particularly useful in high-rainfall zones where yards are cleaned twice daily. The collected and stored rainwater is suitable for washing yards. Diverters are easy to install if there is one drainage point from the yard. A large sump is needed, and it is best if gravity can help rainwater diversion.

Re-using water from effluent ponds

Water can be pumped from the second or third effluent pond and stored for use in high-flow yard cleaning systems. This reliable method is commonly used for flood wash and hydrant wash systems. Using raw or untreated effluent can make yards very slippery and increase odour.

For a single pond system, a pontoon and a pond stirrer will also be required if crusting is an issue. Water can be pumped into a storage tank overnight and used to feed the wash pump. If there is no crusting of the pond, avoid using the pond stirrer when pumping water for yard washing. Remember use an effluent pump for this purpose, not a water pump. Avoid using the recycled water close to, or inside, the dairy and mix fresh water in with reused water to control salt levels.

Other options

• Store and re-use plate cooler water providing there is a sufficient volume to ensure effective heat exchange.
• Re-use detergent wash for yard cleaning.
• Catch rainwater from the dairy shed roof.