1Pre-Heat oven 350*
In a large Dutch oven or soup kettle, bring water to a boil. Add the zucchini, carrots, onion and salt. Cook for 8-10 minutes or until vegetables are tender,drain.
2In a large bowl, combine the soup, sour cream, garlic powder and pepper. Fold in vegetable mixture.
Combine croutons and butter, place half in a greased 13x9 inch baking dish.Top with vegetable mixture and remaing croutons.
3Cover and bake at 350* for 30 minutes. Uncover, bake 10 minutes longer or until golden brown.