Cream together sugar and margarine. Add eggs, one at a time. Add mashed bananas and water to creamed mixture. In a separate bowl, combine flour, baking soda, salt, baking powder. Add gradually to the creamed mixture. Add chopped walnuts and reserve some sprinkle on the top of the bread. Grease loaf pan, 350 degrees for 55-60 min or until toothpick comes out clean. Makes one loaf.