History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c32.s2.t6.7

v1.c32.s2.t6.7

Trees arrest the soil erosion due to sudden or frequent floods and also hold up the water level which would fall without the banks. Hence the presence of trees near the tank was found very useful. Moreover, they contain some tannin in them. The tannin adds a slight sweet taste to the water and thus masks any excess of chlorine in drinking water. "It is also useful in cleaning the water of its impurities on the surface by carrying down to the bottom all dirt and clay that the water may contain, thus serving the same purpose as alum”. Hence these trees are generally planted near the bunds of drinking water tanks" (Venkatarama Iyer, 1916, p. 184).