Preheat oven to 350°. In a large bowl, combine the flour, sugar, baking powder, baking soda, and salt. Set aside.
In another bowl, combine egg, orange juice, water, butter and orange zest. Add to dry ingredients, stirring just until combined. Gently fold in the blueberries. Pour into a greased and floured 8x4-in. loaf pan.
Bake at 350° for 65-70 minutes or until a toothpick inserted in the center comes out clean. Cool for 10 minutes then remove from pan to a wire rack.