▁is ▁left ▁open ▁to ▁allow ▁rain water ▁to ▁fill ▁the ▁structure . ▁ ▁As ▁one ▁structure ▁fills , ▁then ▁the ▁overflow ▁fills ▁the ▁next ▁ch au ka ▁and ▁so ▁on . ▁ ▁Ret aining ▁the ▁rain water ▁in ▁this ▁way ▁helps ▁prevent ▁soil ▁er os ion ▁and ▁re charg es ▁the ▁surface ▁water ▁en abling ▁various ▁grass es ▁to ▁th rive . ▁ ▁This ▁has ▁the ▁effect ▁of ▁holding ▁the ▁soil ▁together ▁and , ▁as ▁the ▁ch au ka ▁system ▁is ▁used ▁mostly ▁on ▁common ▁land , ▁provides ▁gra zing ▁areas ▁for ▁cow ▁and ▁go at ▁her ds . ▁For ▁this ▁to ▁be ▁effective ▁it ▁is ▁combined ▁with ▁the ▁plant ing ▁of ▁grass ▁se eds ▁and ▁trees . ▁ ▁This ▁system ▁is ▁widely ▁in ▁use ▁in ▁the ▁D ud u ▁block ▁of ▁Ja ip ur ▁district ▁in ▁Raj as than , ▁India . ▁ ▁Here ▁a ▁local ▁village ▁development ▁organisation ▁G V N ML , ▁working ▁in ▁the ▁area ▁of ▁Natural ▁Resource ▁Management , ▁has ▁been ▁responsible ▁for ▁its ▁u pt ake ▁among ▁local ▁villages . ▁ ▁See ▁also ▁Rain water ▁har vest ing ▁Water ▁conservation ▁Agricult ure ▁ ▁References ▁ ▁Category : W ater ▁resources ▁management <0x0A> </s> ▁Alfred ▁Oliver ▁ ▁( ▁– ▁unknown ) ▁was ▁a ▁Wel sh ▁international ▁footballer . ▁He ▁was ▁part ▁of ▁the ▁Wales ▁national ▁football ▁team , ▁playing ▁ 2 ▁matches . ▁He ▁played ▁his ▁first ▁match ▁on ▁ 6 ▁March ▁ 1 9 0 5 ▁against ▁Scotland ▁and ▁his ▁last ▁match ▁on ▁ 2 7 ▁March