Excavatingsandsandgravelonlandincombinationwithconstructingreservoirsforstoringfreshwaterisanidealapproachinatolls.Appropriateminingofgravelfromtheprogradinggravelbeachisacceptable.Diggingreefrockclosetotheedgeofthewideoceanreefflatwithoutsurfaceloosesedimentsonitorsandbeachcanbeaccepted.Excavatingsandfromsomedepthsinlagoonisascientificapproachparticularlyimportantforurbanizedatolls.However,selectingappropriatesitesforminingsandotherthanatsomedepthsinlagoonissuitabletoruralislandswithoutdensepopulations.Thesesitesincludeupdriftsideoflonggroinonthereeffiat,partlyfilledaccesschannel-port,outletofartificialchannelandlagoonmarginontheprogradingcoast.
