Runoff water diversion to infiltration basins
A system of hand dug canals (main diversion canal and secondary and/or tertiary canals) conveys and distributes the captured water from ephemeral rivers, roads and hillsides to the cultivated fields. Agriculture under this system would thus receive runoff water besides rainwater to supply its water requirements. The runoff harvested, could be stored for later use or could be lead to the field immediately. The measure provides water to fulfill crop water requirements, increases soil moisture and recharges the ground water level. Besides, it supports the control of runoff water.
To avoid water loss, the receiving fields could be divided into rectangular basins bordered by ridges. This also minimizes erosion risk. Another option would be to lead the water to infiltration pits. Centering crops around such pits would further improve irrigation efficiency.
This practice needs preparedness for immediate action by the farmers: When high rainfall is expected and the in the catchment, farmers should be available to start erecting the embankment across the bed of the stream. Similarly, each farmer starts to maintain the canal which leads water to his field. A schedule should be prepared collectively, defining the date and time each farmer is allocated his turn to irrigate. When the water reaches the field, it could be spread either through flooding or distributed in furrows which are opened and closed using a local tool.
While the diversion canals and basins for tree planting are permanent structures under proper maintenance, basins for annual crops are seasonal. Maintenance is needed every season before the onset of rains. Soil fertility (and hence water retention) could be improved by additional measures such as composting and mulching.
