Cook sweet potatoes in boiling water to cover 35 to 40 minutes or until tender. Let cool to touch; peel, and cut into 1/2-inch slices. Combine sugar, butter, cinnamon, and pecans. Arrange a layer of potatoes in a lightly greased 13- x 9- x 2-inch baking pan. Sprinkle half of sugar mixture over potatoes. Repeat layers. Add water, and sprinkle with orange rind. Bake at 350° for 35 minutes.