In a Dutch oven or soup kettle, bring water to a boil. Add broccoli, celery and carrots; boil 2-3 minutes. Drain; set vegetables aside. In the same kettle, saute onion in butter until tender. Stir in flour to form a smooth paste. Gradually add the broth and milk, stirring constantly. Bring to a boil; boil and stir for one minute. Add vegetables and remaining ingredients. Reduce heat; cover and simmer for 30-40 minutes or until vegetables are tender. Serves 6-8 (2 quarts).