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X – Plan A – Refurbish the old bore

X – Plan B – Drill a new bore.

? – Plan C – Fix the Dam Wall.

When looking back at our ability to secure water for the farm we’ve been about as successful as Phi Tufnell’s fielding.  We tried Plan A (refurbish the old bore) and Plan B (drill a new bore).  Now it was time for Plan C – Call back our trusty earthmover man (Bevan) and “Fix the Dam Wall”.

In 2017 Cyclone Debbie had taken out a good proportion of the farm’s main dam wall and if we are ever to retain enough water to sustain our herd then it would need to be fixed and designed so it wouldn’t happen again.  Now the challenge with our situation is that we effectively have 80 acres of catchment pouring into the dam.  Perfect for your average run of the mill summer rain but devastating in major rain events.

The plan was to create an overflow and spillway as wide, long, and flat as possible to slow the water as it escaped the dam.  It also needed to be fortified so it would resist erosion. Looking at our situation Bevan calculated that a 15m by 4m overflow would do the trick. 108 tonne of rock later with some anchor stones that would not look out of place at Stonehenge, we were in business.

The silver lining from this drought was that the dam was bone dry and could be de-silted quiet easily. In fact, we would claim back another 2m of depth through the process.  After another day of scraping, we had what resembled a pretty decent hole in the ground.

In the picture on the left, our Polaris looks more like a moon buggy from an Apollo mission than a farm vehicle.

With our job done it was down to Mother Nature to do her bit.  Now the summer of 2019/20 wasn’t an exceptionally “wet” season but 200mm in the first half of February was enough to raise the water level to the brim of the overflow.  We were amazed and excited to see that a good but not great summer could fill our dam.

Based on my O-Level maths I calculated that we had over two megalitres to play with. All of a sudden the world was a better place……..

……….. except for the small problem that the level of the water is dropping way quicker than expected – way more.

I’ve done some investigation and it comes down to the following possibilities:

1.  I’ve underestimated the effect of the Australian climate on water evaporation.
2.  There’s a leak
3.  The land is so dry it is sucking the moisture back into the water table
4.  The material on the floor and walls of the dam needs to settle

It has been quite disheartening to think that after all our efforts to sure up the water supply we still don’t have an answer.  I must admit this setback has taken the wind out of me for the next while but I’m sure I’ll get back on the horse soon.  After all, there is nothing that thought, effort, time, and (unfortunately) money can’t fix.

When we bought the farm Jacqui and I agreed we needed to secure clean water as a priority.

Although the dam on the western end of the property “had never run dry” it had taken a battering from Cyclone Debbie and was limping along with a broken wall as a result of the extreme amount of water the rain event had caused.

We noticed some old infrastructure that looked suspiciously like the remnants of a windmill and bore leading up to some old concrete tanks. A basic “pebble test” was conducted where we dropped a pebble down the pipe and counted until we heard the splash. There was definitely water down there! Excited by the prospect of a bore that just needed a bit of love and attention we engaged some local experts to hook up a pump to test the flow.

Seemed like a good idea at the time. First we’d “blow out” the bore and then pump out the pristine water that would be used from everything from watering the livestock to irrigating future crops. (Oh my naivety!!). Hhhmmmmm. Firstly the truck to blow out the bore could barely squeeze through our gate never mind traversing our “rolling hills”. So Take Two was to forego the blowing out and just test the flow. Instead of pristine water the liquid that came up resembled more of the stuff in the opening credits of the “Beverley Hillbillies” but instead of Black Gold/ Texas Tea we had a more of a smelly black sludge. To make matters worse the “sludge” was replenishing at a rate of about 200ml per minute. Now given a cow can drink up to 50-70 litres of water per day the queue at the trough was going to be huge!!

Unperturbed it was time for Plan B – drill a new bore. A quick scan of the local contractors and we settled on a reputable local with a history of successful bores in the area. We chose a spot which seemed the most likely for success, after all it was in a similar area the the old windmill and on one of the lowest points on the property. We were feeling confident, our neighbours had shallow bores and the Department of Natural Resources published the stats of active and productive bores to the Southwest (1.5klm away) and to the east (2klm away).

We were so confident we started a sweep on the depth of the bore and enlisted our extended family. Some threw out some quick guesses whilst others (those with the environmental science degree) made more measured assessments taking into account the geological profile of the surrounding bores. (For what it’s worth my guess was 45m).

The day of drilling came and for two hours the contractor expertly manoeuvred two large trucks up our dirt track and down our “rolling hills” to the proposed site. Another hour of setup and the drilling commenced. 5m, 10m, 15m. We were through the expected clay, shale, granite and into layers of coal. 15m became 25m which became 50m. The excitement started to wane only to be rekindled when another layer of coal was found. 50m became 60, 70, 80, 90 metres. At 103 metres we pulled up stumps as we were now just wasting diesel. Even if we hit water the likelihood of it being usable (due to the salinity) was low and the cost of the pump would have been astronomical.

So Plan B also didn’t go as hoped. Maybe in the future we may dabble with a water diviner ( it’s amazing how many of the local “traditional” farmers asked if we used one) but until then we are on to Plan C – fix the dam wall.