In a 6-quart saucepan, heat oil over medium-high heat. Add fennel, onion, carrots, celery, and garlic. Cook 3 minutes, or until softened. Stir in water, chicken broth, and tomato sauce; heat to boiling over high heat. Add macaroni and cook 7 minutes.
Reduce heat to medium-low, and stir in tomatoes, beans, and zucchini. Cover and cook until beans and zucchini are heated through, about 10 minutes.