Reaching water to the hillside plot will be difficult. It is at an altitude and inaccessible by larger vehicles. Pumping water from lower places such as a pond below is also impractical because of distance, height etc. Bore well may be ecologically damaging and may cause neighbouring wells to dry up by driving down the water table. The option other than depending only on the rains is to store the rain water for use in dry season.
We enquired about implementing a rainwater Harvesting system. One option is to construct a tank below at the lowest level of the land so the whole plot will be catchment resulting in higher water yield. Then for irrigation we will need long piping and excess electricity to reach the water along the whole portion pumping up. The other option is to build tank at highest level which will have negligible catchment. It will mainly depend on the rain falling on the area of the tank directly but will be easier to distribute water as it can use gravity.
The success will depend on adequate rain falling directly over the tank. We don't have exact rainfall data for this place but assume that it would be reasonably high in the region of 100cm upwards. There would be evaporation loss from surface which would also need to be accounted.
We could also locate the tank midway up the plot, above the terraces, at the lower side of the steeper slope.
There is scarcity of reliable and useful information on the subject with regard to farming. Government RWH schemes focus on households and well recharging. The attitude of most people we enquired on the subject has also been negative/ discouraging.
The tank will need to be dug according to our specification in a trapezoid shape. It will then be covered using HD PVC sheet to prevent seepage. The sheet can be weighted down firmly in place using bricks on top of it to line the side walls. To prevent dirt and leaves from higher catchment from entering a small side trench can be dug. Also a wire mesh vertical short wall outside the tank walls will block debris. The tank can be covered up after the rainy season to reduce evaporation loss and control mosquito breeding.
Calculation :
Area of Tank x rainfall expected = volume of water
1000 liter = 1 meter cube
We enquired about implementing a rainwater Harvesting system. One option is to construct a tank below at the lowest level of the land so the whole plot will be catchment resulting in higher water yield. Then for irrigation we will need long piping and excess electricity to reach the water along the whole portion pumping up. The other option is to build tank at highest level which will have negligible catchment. It will mainly depend on the rain falling on the area of the tank directly but will be easier to distribute water as it can use gravity.
The success will depend on adequate rain falling directly over the tank. We don't have exact rainfall data for this place but assume that it would be reasonably high in the region of 100cm upwards. There would be evaporation loss from surface which would also need to be accounted.
We could also locate the tank midway up the plot, above the terraces, at the lower side of the steeper slope.
There is scarcity of reliable and useful information on the subject with regard to farming. Government RWH schemes focus on households and well recharging. The attitude of most people we enquired on the subject has also been negative/ discouraging.
The tank will need to be dug according to our specification in a trapezoid shape. It will then be covered using HD PVC sheet to prevent seepage. The sheet can be weighted down firmly in place using bricks on top of it to line the side walls. To prevent dirt and leaves from higher catchment from entering a small side trench can be dug. Also a wire mesh vertical short wall outside the tank walls will block debris. The tank can be covered up after the rainy season to reduce evaporation loss and control mosquito breeding.
Calculation :
Area of Tank x rainfall expected = volume of water
1000 liter = 1 meter cube
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