5-Bring water to the farm
Raising the level of the water source, by building a dam you can raise the water level in the stream so that water flows more easily into your ponds. Possibility of building a simple dam using intertwined branches or stones arranged at the bottom of the watercourse.
When the sheet of water behind the dam you have built reaches its highest level, you will need to build a feed trench to bring the water to your ponds.
Dig the trench immediately behind the dam, about 1 m from the edge of the water (so that the water does not flow into the trench). When you are ready to put your ponds in water, you can remove this 1m strip and the water will flow into the trench.
The trench must follow the shallow side of your ponds and go in the same direction as the stream that feeds you. It will have to be sloping gently. When you reach your highest pond, the trench should be near the water inlet. Continue digging your trench until you reach your lowest pond.
When the feed trench has passed the end of the lowest pond, continue digging it down about 10m.
Then bring it gently to the ground. In this way, when you put your ponds in water, the excess water will flow at ground level.
Now, dig a trench to communicate the water inlet of each pond with the feed trench. Keep the level of the background horizontal.
Digging a trench back
To return the water to the watercourse when you empty your ponds. From the deep end of the pond making it as short as possible.
Water supply control of your feed trench
To regulate the water flow in your intake trench you can build a lock. This lock will have three slots in each wall. Two of these three sets of slots will receive boards and the third a grid designed to stop unwanted fish.
Build this lock at the top of the feed trench just behind the 1m strip of land you left at the water’s edge when you started digging the trench. Fill the gap between the planks with soil until you need water for your fish farm.
Place a lock at the lower corner of each feed trench.
Thanks to the United Nations Food and Agriculture Organization (F.A.O) for supporting this article.