In a large slow cooker, combine carrots, potatoes, onions, tomatoes, zucchini and water. Season with salt and pepper to taste.
Cover and cook on LOW for 8 hours or until vegetables are tender. Stir in beans and pasta. Cook until pasta is tender, about 30 minutes. Taste for seasoning.
Spoon soup into serving bowls. Top each bowl with a spoonful of pesto and serve hot.