I am trying to evaluate and have the following questions answered:
- when are farm ponds an option?
- how effective are farm ponds?
- what should be the realistic expectation of the output from a farm pond?
- Annual average rainfall of 700 mm distributed over 3 weeks in July
- Medium-light soil with good permeability
- Land topography allows harvesting in pond
- Land area of 15 acres
- Rain water is the only source for harvesting, no runoff from neighboring lands is available
- The harvested water is allowed to percolate in contour trenches/swales; only excess water beyond them is collected in pond(s)
- No other source of water for cropping - no wells or borewells in the land
- 1 ha can collect 250m[sup]3[/sup] of water into a 12m x 12 m pond
- Evaporation losses are 50% of collected water
- Percolation losses are 5% of collected water, reduced to this level by use of plastic sheet
I will update this topic with my thoughts, all inputs welcome!