*10.2.3.1 Catchment*

The area used for collection of water is called catchment the area can be smooth or unsmooth surface, such as rooftop, plot (garden, driveway etc). the water flowing through catchment need not to be clean, once they percolates through soil the dirt particles in water can be removed since soil acts a natural filter. The only care should be taken when using chemical residues, even small amount would have impact on whole ground water. Utmost care must be given while considering gardens and farmlands since there are high chances of using fertilizers and pesticides (**Figure 9**).
