item no.4 :-providing, constructing coffer dam in river basin / dam storages as per type design including excavation, filling the middle portion with b.c. soil (in gunny bags if required). providing impervious / semi-pervious materials on both side of b.c. soil (in gunny bags if required) including ramming, compacting to the satisfaction of engineer in charge, till the completion of work including dismantling coffer dam after completion of works and disposing off the material as directed by the engineer in charge.
coffer dam for intake well
