Blend water, pineapple, gelatin, and sugar together in a blender for 15 seconds. Add cranberries and blend an additional 15 seconds. Stir celery, walnuts, chopped orange, apple, and orange zest together in a large bowl. Pour blended pineapple mixture into celery mixture and stir until completely combined. Transfer mixture to a serving bowl, cover the bowl with plastic wrap, and refrigerate until set, 8 hours to overnight.