Farm Water Management
Shared to provide inspiration and ideas for your circumstance.
Below is a brief description of the water management plan at Pindari. Irrigation water for the farm is the major issue we currently face with the last two season's rainfall has been only two thirds of the average and it has been intermittent and at times un-seasonal.
The farm occupies 20 hectares of land, sitting on top of a rocky dolerite hill 300 metres above sea level. It has a shoulder of land running across to another hill. The land lies in the rain shadow of the western and eastern mountain ranges.
There are two major dams with small catchment basins on either side of the shoulder of land with contours around the hill for greater catchment. A wet winter is required to fill the higher dam but when full the water level is only 4 meters below the pump shed and thus requires less energy for pumping. The lower dam fills much more quickly but lies some 30 meters below the top dam. Water from both dams is used for watering the garden via electrical pumps with the use of a petrol driven fire pump also available.
We can pump either directly to the garden or to two storage tanks situated at the highest point in the gardens giving a 2.5 metre head of water that allows sufficient pressure to use small sprinklers and a drip hose to most areas of the garden. The plumbing to the storage tanks from the dams is with underground 40mm black poly pipe and the water to the gardens is circulated via a net work of underground 25 mm poly piping with taps at appropriate locations. We are able to cover the garden areas adequately in the dry of midsummer if there is water in the dams using power from the wind generator on windy days.
All roof water is collected and stored in a 50.000 litre concrete tank. We pump water once or twice a day to a converted 500 litre stainless milk vat in the roof of the main house using a centrifugal pump. All taps in the house are then gravity fed. We also pump water from a bore that produces little but high quality (mineralised) water. This goes directly into the house header tank. All water-holding facilities are covered to avoid the breeding of mosquitoes and other insects.
Addendum August 2009
After spending much of our resources on increasing the size and catchments of our two dams, this year we have had a very wet winter and we now have enough water for irrigating the garden for possibly 3 years. With a forecast warm dry spring this water could be needed for 'growing out' this years food crops.
Our decision to increase the water holding capacity of our dams in order to prepare our farm for the forecast extremes in weather has paid off.