When the dam went dry
Host: Eversleigh Station
Written by Jenny Underwood – Owner, Eversleigh Station.
Water is vital for the survival of all living things. Many properties have at least one dam that provides water to its stock. On “Eversleigh” we only have one large dam with all of our other watering points connected to a system of tanks and bores.
Little Horse dam. In March 2012 there was good widespread rain which filled the dam to capacity. The last time this dam went empty was in the mid-90s.
During times of low rainfall and drought water levels in dams must be closely monitored.
July 2013 Pelicans on the dam. The absence of a wet season with little to no runoff has already affected the dam level. The summer of 2012/2013 also recorded extreme temperatures and multiple heatwaves, all of which caused rapid evaporation.
By the end of 2013 the dam was rapidly drying up. The water quality was far from ideal and some cattle were starting to bog while trying to get a drink.
December 2013. The dam is nearly empty. You can see dead fish floating on the surface of the dam.
It was vital that we set up an alternative water trough near the dam for the cattle as soon as possible. We had a stockpile of polypipe, tanks and troughs on hand for such emergencies. Water was to be gravity fed from a tank in another paddock about 4km away.
A load of 63mm polypipe loaded on the truck ready to go out to the line. We could fit 10 – 12 coils of poly per truckload.
Loading a coil of poly onto the poly spinner. Each coil is 200m in length (and very heavy).
The spinner unrolls the polypipe along the line. Great care has to be taken that the poly doesn’t kink or get caught on the spinner.
After each 200m coil is laid out the next coil has to be joined. The ends are curt off using a hacksaw or a cutting tool which makes a neat, even cut.
The end of the polypipe is bevelled to allow a neat fit into the poly joiner.
Fitting the joiner to attach the two coils together.
The two separate coils of polypipe are joined together.
This process was repeated every 200m until we reached the tank 4km away.
Once the polypipe is filled with water and is checked for leaks the grader will be used to dig a trench and the polypipe will be buried about 50cm under the ground. Generally laying and burying a polyline is done in the cool of night as the line can expand and stretch during the day. If it is buried too hot, once the ground cools down the poly can pull apart at the joins.
Before connecting the poly into the water source the new tank and trough needed to be put in place.
A 27 000L tank and a cement trough on the back of the truck ready to be unloaded and put into place.
The tank is put into position after an area was cleared and made level. A loader is being used to lift the trough off the truck. The trough weighs 1.6 tonne.
A “site manager” oversees the trough being put into position. The trough needs to be sloped slightly downhill so that when it is cleaned the water drains away from the bunghole. You can see that the bull has been wading into the dam to get a drink by the mud which is up to chest level. This shows how easily cow and calves can quickly and easily become bogged when a dam is going dry.
In late December Roger was able to start a temporary clean out using a small loader. By the beginning of 2014 the dam was “dry enough” to start desilting it. Two big loaders worked 12 hour shifts and took nearly a week to clean out the dam. About 4 metres of silt was removed.
14 February 2014. The dam is cleaned out and ready to fill. BRING ON THE RAIN!
We did receive some rain which put some water into the dam but sadly not enough to make much of a difference.
10 October 2014. Once again the dam was nearly empty but at least having desilted it meant that any cattle wanting to walk down to the water wouldn’t bog.
It is now March 2015. The dam is still empty.