Cook manicotti; rinse; drain. Coarsely shred zucchini and cook in butter for 7-9 minutes. Add cottage cheese and 1 cup of shredded cheese. Mix well. Stuff shells with cheese mixture. Arrange in shallow 2 quart baking dish.
Mix spaghetti seasoning mix, tomato paste and water. Spoon over manicotti. Cover with foil. Bake 325 degrees 30-40 minutes. Uncover, sprinkle with remaining shredded cheese. Bake 10 minutes longer. Just before serving, sprinkle with Parmesan cheese.