▁ ▁Beach ▁n our ishment ▁often ▁involves ▁exc av ation ▁of ▁sed iments ▁from ▁river bed s ▁or ▁sand ▁quar ries . ▁ ▁This ▁exc av ated ▁sed iment ▁may ▁be ▁substantial ly ▁different ▁in ▁size ▁and ▁appearance ▁to ▁the ▁naturally ▁occurr ing ▁beach ▁sand . ▁ ▁In ▁extreme ▁cases , ▁beach ▁n our ishment ▁may ▁involve ▁pla cement ▁of ▁large ▁p eb bles ▁or ▁rocks ▁in ▁an ▁effort ▁to ▁perman ently ▁restore ▁a ▁sh or eline ▁subject ▁to ▁constant ▁er os ion ▁and ▁loss ▁of ▁for esh ore . ▁ ▁This ▁is ▁often ▁required ▁where ▁the ▁flow ▁of ▁new ▁sed iment ▁caused ▁by ▁the ▁long sh ore ▁current ▁has ▁been ▁dis rupted ▁by ▁construction ▁of ▁har b ors , ▁break w aters , ▁cause ways ▁or ▁boat ▁ram ps , ▁creating ▁new ▁current ▁flows ▁that ▁sc our ▁the ▁sand ▁from ▁behind ▁these ▁structures ▁and ▁dep rive ▁the ▁beach ▁of ▁rest or ative ▁sed iments . ▁If ▁the ▁causes ▁of ▁the ▁er os ion ▁are ▁not ▁addressed , ▁beach ▁n our ishment ▁can ▁become ▁a ▁necessary ▁and ▁permanent ▁feature ▁of ▁beach ▁maintenance . ▁ ▁During ▁beach ▁n our ishment ▁activities , ▁care ▁must ▁be ▁taken ▁to ▁place ▁new ▁sed iments ▁so ▁that ▁the ▁new ▁sed iments ▁compact ▁and ▁stabil ize ▁before ▁ag gress ive ▁wave ▁or ▁wind ▁action ▁can ▁er ode ▁them . ▁Material ▁that ▁is ▁concentr ated ▁too ▁far ▁down ▁the ▁beach ▁may ▁form ▁a ▁temporary ▁gro y ne ▁that ▁will ▁encou rage ▁sc our ing ▁behind ▁it . ▁Sed iments ▁that