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Maintaining Spring or Soak

By David Hunter

The existence of permanent water springs is a factor which enhances the drought resistance of a farming or grazing property. It is definitely a factor which should be borne in mind if you are currently on a search to buy your first property or considering a move from your current property to a more drought resistant one.

Alternatively, if you live in hilly country you may actually be aware of some springs on your property which you might like to develop as a reliable stock water source rather than just a boggy patch on a hill side. The case of a 1600ha cattle grazing property in hilly country at Dawson’s Hill, NSW, provides a good example of the value of springs and what can be done to enhance their usefulness. The property, Glen Oak, is owned by Tim and Jan Harrison.

One interesting feature about the topography in the area is that a series of impervious granite rock bands or shelves run through the area at various depths beneath the ground and, at some points of the hill slope, they come near to the surface or break through the surface. The shelves slope generally West to East and so this sets up the pattern where springs are likely to occur. Tim Harrison reports, “The altitude variation on our property varies between about 400m and 600m and the interesting thing is that springs occur at all levels on the property. This shows that water is actively moving underground along the lines determined by the rock bands. “Uniquely, there are a series of springs on a high plateau almost at the highest point on the property,” he says.

This interesting formation is called ‘Jolly’s Springs’ after a man who lived up on the plateau in the 1860’s. At Jolly’s Springs there are at least six permanent springs in an area of about 250m x 50m. They are so reliable that they remained a reliable source of water throughout the worst times of the recent drought. With the presence of large numbers of cattle on the property Tim reports that the springs need to be managed to ensure their best effectiveness for the property.

Without a management plan the cattle can get in and trample the source of the springs. This may lead to the worst case where the spring becomes compacted and stops running. The water will still go somewhere, but it may not break the surface again on your property. Without management the spring can also just become a boggy marshy patch with no free water at all for stock consumption.

This problem can get worse if cattle get into the bog during a dry spell and make it even more of a boggy mess. In order to best manage the water source at Jolly’s Springs, Tim Harrison has taken the following steps:- Created small ponds immediately downhill from the springs where the water can gather in a form accessible to stock. The free water in these ponds also becomes a water source for the development of other bio-diverse life forms such as reeds, insects, birds and wildlife. Protected the springs themselves. In developing the ponds Tim has taken great care not to disturb the ground - often only a few square metres - where the spring actually breaks the surface. By working this area with machinery Tim would be running the risk of compacting it and closing off the flow. Protection measures also include fencing off the immediate area of spring itself so that stock are excluded.

Used troughs as stock watering points. Once the pond has been established, Tim limits cattle movement to the pond by distributing water to a series of troughs a long distance from the pond. This means that the ponds themselves are not exposed to heavy cattle pressure and the ground around the trough does not become trodden down and eaten out. It also creates another efficiency because it enables water to be reticulated to stands of grass on the property which might otherwise be under utilised because of their distance from water. Finally, the use of water troughs creates a feed conversion benefit in the cattle because they are not required to expend so much of their energy walking to water in hilly country.

Used gravity rather than pump energy. Due to the unusual fact that Jolly’s Springs are at almost the highest point on the property, it is possible for Tim to move the water for distances of up to 2km using gravity rather than a diesel powered motor or electrically driven pump. The water can easily be moved in 25mm low pressure poly pipes and its rate of flow can be controlled using simple ball and float technology.

The ability to deliver the water to many points on the property using gravity creates a huge cost saving.

The management plan for springs lower in the hill profile of the property is less sophisticated than the management of Jolly’s Springs. Lower in the hill profile the pan usually involves ponding the water, and creating cattle access. The many springs on the property, and the manage-ment interventions to optimise their effectiveness, have been an essential component in running the property profitably during the drought.

There are practical difficulties in assessing the total water flow from a spring. However, using the technique shown in the photograph,left, we were able to calculate that the free flow on one of the small springs in Jolly’s Springs was about a litre every four minutes. This measurement was taken after the worst drought in a hundred years. In an hour this spring could be assumed to deliver 15 litres and in a day 360 litres. And remember, this flow goes on day and night, week after week, without stopping. The springs at Jolly’s Springs have differing rates of flow but, assuming they are all the same rate as this smaller spring, the daily water availability from the group of springs is at least 2160 litres.

This is a very conservative figure because the observable water in the ponds and in the troughs would appear to be in excess of this amount. However, the figures go to show the long term benefit of a permanent trickle of water. Spread over the rest of the property are many more individual springs and, together, these form an enormous water asset if managed correctly.

Tim notes that springs are very important in this type of upland country. While it is true that the annual average rainfall is an enviable 1000mm, it is also true that the high slopes of the hilly terrain lead to a high run off immediately after rain. This means that the country can dry out very quickly in a few weeks after rain if there is no follow up. This contrasts with flatter areas where more water soaks in after rain.

Ponds which form in the rocky creek line are a great reserve of water as the country dries out. But the ultimate reserve and most reliable long term water asset to help drought proof the property are the large number of natural springs. Tim sees the correct management of these as a fundamental farm skill.