Last Thursday, intrepid students from Grade 9/10 attended an excursion to the Poatina Buffer Dam site – the start of the Tasmanian Irrigation’s Northern Midlands Irrigation Scheme. Together with students from Bothwell, we donned hard hats and safety glasses, before circumnavigating the dam wall. Contractors were spreading grass seed on the external wall, among the first to use water from the dam in the process. We passed the gates which feed Poatina race water into the dam, and the pipes which will pump it south. We learnt about technology inserted into the wall to give warning of moisture and movement, and the importance of the spillway to the structural integrity of the wall.

The students met with engineers, project managers, machinery operators and construction supervisors, learning about career pathways and the numbers of different people involved in the construction of the irrigation project. The vast amount of rock moved from Elizabeth Town for the wall involved many truck loads for months was incredible.

Students were shown how drone technology has improved timely decision making which has reduced misplaced material, improved efficiency and saved money. They got to turn on the gates (pressed the button) and see the initial area fill. It was interesting to watch as the buffers reduced the velocity of the incoming water as it spilled out into the dam. The final activity saw the sieving of a gravel sample into 12 different sizes. It is important the gravel has just the right mix of particles to ensure it holds back the water.

The day ended with the best BBQ lunch ever.  Hazell Bros turned it on with steak, salad, cheese, snags, onions and meat patties. A very big thank you to the Hazell Bros Group, Tasmanian Irrigation and the Beacon Foundation for organising the day.

Jill Bennett

AST