Under natural conditions, the presence of surface vegetation and leaf litter provides ample opportunity for rainfall to be intercepted, detained and infiltrated – even in area with moderate to steep slopes. Generally speaking, only about 10% of the annual rainfall amount in such areas is lost as surface runoff. The rest of the water supports the growth of vegetation (40%), feeds nearby watercourses (20%) and recharges aquifers (20%). | Under natural conditions, the presence of surface vegetation and leaf litter provides ample opportunity for rainfall to be intercepted, detained and infiltrated – even in area with moderate to steep slopes. Generally speaking, only about 10% of the annual rainfall amount in such areas is lost as surface runoff. The rest of the water supports the growth of vegetation (40%), feeds nearby watercourses (20%) and recharges aquifers (20%). |