water release at o`shaughnessy dam due to high levels of snow melt at hetch hetchy reservoir in yosemite national park; one of

alpine america bay california concrete construction dam drinking due energy engineering floodgate flow flowing francisco hetch hetchy high hydro hydroelectric industry lake landmark landscape large levels main melt mountains national nature one oshaughnessy outdoors overflow park popular power release reservoir river runoff rushing san scenery scenic sierra snow snowmelt sources states structure supply system technology tuolumne united usa valley view wall water yosemite