drying sand stream

you shoot out a maximum 70 ft long and 1 ft wide sand line ( basically yea but nvm).the creatures in range need to take a saving throw. if it fails the creatures got hitted by the stream get 2d12 dry  damage (ranged attack) and 1 dry stack. and if its a succes it gets only 1d12 dry damage (ranged attack) instead of 2d12 dry damage (ranged attack).