I used the tractor with a grader blade to dig out a small pond. I estimate that it is about 10 thousand litres when full.
The purpose of this pond is to filter water run off from the neighbouring paddocks before it flows into the main dam. The main dam is about 1 megalitre. The pond will be planted with a variety of water plants, the more species the better. The plants will trap nutrients and toxins from the run off before feeding the main dam.
In this kind of system it will most likely be necessary to ‘harvest’ the biomass from the pond every now and then to be disposed of. The pond needs to have actively growing plants in it for it to function. I reckon if I cut it back every second year and distribute the biomass in the woodlot that will do the trick.
I decided to give the fire/transfer pump a run and fill the pond. A simple way to check that the spillway is at the right level too.
The diversion drain enters the perched pond at the lower right in the picture below and spills into the main dam to the top left.
I threw in an armful of aquatic plants :
- Milfoil aquatica
Parrot’s Feather milfoil
Cumbungi bullrushes have started to grown in all the dams now, so I am sure they will turn up soon enough in the perched pond. They are considered by some to be an expansive, aggressive plant and can dominate an aquatic ecosystem. We shall see, I think they look great. The dams all have planting shelves so there are plenty of niches for other plants to grow where the bullrushes cannot dominate.