Water for horses following fires

When you have been affected by a fire there are many things to consider. For horse owners, one of the most urgent and important requirements is to ensure immediate and ongoing access to sufficient clean, fresh drinking water for your animal. You should also consider putting together a longer term plan to ensure you will be able to protect your water supply, the environment, and in turn, the quality of the water.

This page will help you address many of the things you need to consider when it comes to horses and water, including estimating water needs, assessing water quality and long term options for managing water quality.

How much water do I need for my horses?

Horses should have access to clean, fresh drinking water at all times — they cannot go without water for very long. The needs of individual horses will differ greatly, and factors that affect the amount of water a horse needs include:

• Temperature
• Whether they are in work, and what type of work
• Feed (moist grass compared with dry feed)
• Pregnant or lactating mares drink more
• Size and condition
• Health

As a rule of thumb, a horse requires approximately 52 ml per kg of bodyweight each day:

• Ponies (200 to 300 kg bodyweight) require 10 to 15 litres daily
• Light hacks (300 to 450 kg bodyweight) require 15 to 25 litres daily
• Thoroughbreds (450 to 500 kg bodyweight) require 25 to 30 litres daily

These amounts are increased with work, growth or lactation. Two or three times the amount of water shown above may be needed by horses in work. This equates to up to 32,800 litres of water a year per 500 kg horse in work. More information on water requirements for horses can be found in the Code of Practice for the Welfare of Horses (Revision 1),

When calculating how much water you have available, don't forget to factor in losses from evaporation, seepage, drought and other animals including wildlife drinking the water. About 1,500 to 2,000 mm of depth is evaporated from a dam each year although this can vary with the depth and orientation of the dam.

So, to effectively manage farm water after a fire, you should carefully evaluate current reserves, estimate how the status of these reserves may change over time, and consider how this will influence the management options available.

For more information about calculating how much water is in your dams and how long it will last, please refer to our guide, How long will my dam water last?

What level of water quality does my horse need?

Horses would rather go thirsty than drink water contaminated by chemicals, insects, leaves, algae or manure. So where possible, you need to site water supplies away from trees, change the water (if using troughs) and clean the water supply regularly.

Fires generally occur in summer when water supplies may already be depleted, and one of the most frequent water quality problems occurring when water levels are low is high levels of salt. Young horses have difficulty thriving on water supplies with higher than 5,000 ppm (parts per million) salt. Adult horses can handle up to 6,500 ppm, especially once they get used to it. Levels above 6,500 ppm salt need to be treated with caution. You should not use water that contains more than 400 ppm magnesium salts.

If you feel that you may have a mineral problem, whether it be salt or something else, it would be advisable to get your water tested.

What effect will the fire have had on my water quality?

After a fire, windborne material such as ash and soil from paddocks with inadequate ground cover may be blown into dams. Once in the water, organic materials provide ideal food for bacteria and algae. These organisms grow rapidly using up all free oxygen in the water (it becomes anaerobic) and putrefaction results.

Symptoms are dark water, a bad smell and black scum around the dam's edge. Horses and other livestock find such water unpalatable. Thick scum around the water's edge may also prevent animals accessing the water. It is believed the water is not poisonous to livestock, but it may be harmful to young or weak stock.

Once material is in the dam, aeration of the water is necessary to improve its condition and make it more palatable. This is best done by pumping to a tank and reticulating to a trough. If aerated water is returned to the dam, the organisms growing on the organic material will quickly remove all the air again.

Fencing can be used to trap blowing material before it reaches the water. A closed-wired fence on the windward side is a worthwhile investment. The offending material eventually settles and can be removed with an excavator.

It is also important to protect dams from siltation. During summer, storms can move large volumes of silt. This can happen any time until ground cover establishes.

What are my options in the longer term for managing my water quality?

Whether you are considering developing a whole farm plan for your property after the fire, you already have one in place, or whether you have not even thought about it yet, water quality is a crucial factor in managing your horses and property.

There are a number of ways water quality on your horse property can be improved, for example:

• Provide troughs instead of relying on creeks and dams
• Fence off dams and allow horses restricted access or no access, and pump water instead. This protects dam walls, avoids silting up of dam inlets and overflows, and stops horses from churning up, and muddying their drinking water.
• Restrict access to creeks, which protects the watercourse and the stream banks.
• Ensure horse paddocks have good ground cover at all times. Groundcover acts as a filter and disperses the water as it approaches creeks and dams or enters the groundwater supply.
• Consider planting shelterbelts to help disperse and absorb excess water.
• Direct water from shed or stable roofs into a tank, or alternatively into drains or over a grass area.
• Disperse water from washing your horse over grass areas, and make sure it cannot enter waterways.

Further relevant material is available in the following fact sheets, available on our website:

• How long will my dam water last?
• How to maintain your farm dam
• Measuring the salinity of water
• Water quality for farm water supplies
• Has your dam got a blue-green algae problem?
• Drought feeding and management for horses

More information about keeping horses can be found in the Horses section of our website.

For further information, contact our customer service centre on 136 186.