▁opposition ▁from ▁neighb ors ▁and ▁recre ational ▁enthus iast s . ▁The ▁oppon ents ▁cont end ▁that ▁hundreds ▁of ▁tr uck s ▁would ▁be ▁required ▁that ▁would ▁increase ▁poll ution ▁and ▁noise . ▁They ▁also ▁say ▁that ▁the ▁wild life ▁habitat ▁will ▁be ▁destroyed ▁and ▁inter f ere ▁with ▁h ik ers , ▁cycl ists ▁and ▁horse back ▁rid ers ▁who ▁use ▁the ▁area ▁for ▁recre ation . ▁The ▁alternative ▁supported ▁by ▁Pas ad ena ▁officials ▁would ▁have ▁removed ▁ 1 . 4 ▁million ▁cub ic ▁yards ▁of ▁sed iment ▁() ▁and ▁provided ▁regular ▁maintenance . ▁County ▁officials ▁supported ▁removing ▁more ▁sed iment ▁to ▁reduce ▁the ▁flo od ▁risk ▁for ▁most ▁major ▁storm s , ▁the ▁work ▁having ▁begin ▁in ▁early - 2 0 1 9 . ▁ ▁Below ▁Dev il ' s ▁Gate ▁Dam , ▁most ▁of ▁the ▁Ar roy o ▁Sec o ▁cre ek , ▁with ▁two ▁short ▁exceptions , ▁is ▁contained ▁in ▁a ▁concrete ▁channel ▁that ▁contains ▁storm water ▁and ▁municipal ▁run off . ▁This ▁channel ▁and ▁other ▁similar ▁flo od ▁control ▁structures ▁throughout ▁the ▁Los ▁Angeles ▁Bas in ▁and ▁along ▁the ▁fo oth ills ▁of ▁the ▁San ▁Gabriel ▁Mountains ▁were ▁built ▁following ▁the ▁dev ast ating ▁Los ▁Angeles ▁Flo od ▁of ▁ 1 9 3 8 . ▁ ▁Rest oration ▁programs ▁For ▁more ▁than ▁one ▁hundred ▁years , ▁the ▁natural ▁environment ▁of ▁the ▁Ar roy o ▁Sec o ▁and ▁its ▁proxim ity ▁to ▁a ▁large ▁urban ▁population ▁have ▁inspired ▁efforts ▁to ▁protect , ▁manage ▁and ▁preserve ▁it . ▁L