Water is essential for any farm operations. All these while, there have been reliance on rain water harvested off the roof of the shack. However, when I’ve workers staying over and with more newly planted vegetation, water requirements would undoubtedly increase. More water is needed for cooking, washing and irrigation, especially during the dryer months.
I’ve had the blessed opportunity to secure some really good spring water from my neighbour’s oil palm plantation upon getting the owner’s permission. After some research and recce with an altimeter (Garmin watch), I reckoned the levels and distance are just about right to channel water to my farm over a distance of roughly 500m. This can be accomplished with a 1/2 inch pipe.
I may not be able to bring in water to the desired levels but will just have to settle for whatever levels the source offers. If I have to bring it higher, I will have to resort to using a pump. Last I check, the difference in elevation between source and destination is around +/- 5m. The Garmin watch is after all, not that accurate given the circumstances. Near enough is good enough.
Mike and I tracked the water source and decided on the current location to build the mini dam. He concluded based on a study of the vicinity that the chosen location is the most ideal, by virtue of the high saturation of ground water seeping through (even during dry season). There is no doubt; a water table underneath, and perhaps an aquifer beneath. A treasure trove indeed!
The mini dam is situated at a section of a gulley that runs its course through a ravine flanked by oil palm trees on a hilly terrain. We actually went further up the elevation while tracing the gulley upstream but it seems, those areas were just collecting run-offs. The higher one goes, the more likely deeper an aquifer is. So we have to settle for a lower elevation spot (but definitely still higher than my destination at the farm) but still definitely being a promising choice.
The good thing about this mini dam is that it’s preceded by many winding “S” turns. This would help slow down water, trap debris and filter away sedimentation. At the moment, I stacked up only one wall of river stones on the last bend leading up to the dam (see photo above). This would take the brunt of incoming water during a heavy down pour to filter away as much leaves and branches. Sand and mud that make it through would be subsequently stopped by the rear wall of the dam.
Both the rear and front walls of the dam are about 2-3 feet thick. Very large rocks form their foundation (for stable footing) followed by medium to smaller size rocks as they build upwards. Pebbles and sand is then filled into the crevices, followed by mud and rammed earth which is folded into and interspersed with some plastic gunny sacks (not so environmental friendly but that’s the cheapest and what’s available on hand. Count it repurposing).
The large rocks at the bottom are angled in such a way that it interlocks into the side of the dam wall on the slope, against the water flow for added strength. Over time the gunny sack will breakdown and bind into the mud and earth creating a near-perfect tight seal to hold back water. As the finishing touch, Vetiver grasses are planted into the earth mound all around to take root, clean water and provide even further bind on the mass of soil and rocks.
I was told by a contract manager at the oil palm plantation that his workers use the stream water for drinking and cooking, hence no weed killers or chemicals are allowed. They maintain the landscape using a brush cutter. Sounds good. A quick check with the owners revealed the same.
Apparently, only organic fertilisers are now used for the trees, even though, they used to use NPK synthetic fertilisers. Otherwise, it seems to me then that the water should be safe, though I would most like to have it tested. For general washing and irrigation purposes, it would suffice for now. Closer inspection of the crystal-clear water reveals life forms, so I guess it can’t be that bad.
