Mix flour, sugar, baking powder, baking soda and salt in large bowl; set aside.
Blend eggs, margarine, orange juice, orange peel and water in small bowl. Stir into flour mixture just until blended. Stir in walnuts. Spoon into greased and floured 8x5-inch loaf pan.
Bake at 350°F for 50 minutes or until done. Cool in pan 10 minutes. Remove from pan; cool completely on wire rack. Slice; serve immediately.