In a Dutch oven over medium heat, cook the sausage, onion and celery until meat is no longer pink; drain. Add garlic; cook 1 minute longer.
Add the water, potatoes, tomatoes, carrots and seasonings. Bring to a boil. Reduce heat; cover and simmer for 15 minutes. Stir in zucchini; simmer 8-10 minutes longer or until vegetables are tender. Discard bay leaf.