Whirlpool ice maker issue

Have an unknown aged Whirlpool side by side with in door ice and water. Makes ice just fine but I have noticed frozen water on the area underneath the u shaped trough that carries the water from the back of the freezer to the ice tray. I have checked the water pressure at my place and it's 60 PSI. I waited and watched the water valve cycle the water comes down the trough but at high speed / pressure and overflows the side of the trough and therefore gets on the ledge behind the ice maker and actually onto some of the food in this freezer. The filter is new. Do I need to somehow cut down the water supply going into the freezer to stop this from happening? I have lived here just about 2 years the fridge freezer was here when I moved in and it did not do this before. About every two or three weeks or so I have to go chop out the glacier that's forming in the back.