In a 4-qt. large, heavy pot combine potatoes, onion, carrots, celery, broth, water and pepper. Bring to boiling; reduce heat. Cover and simmer 20 minutes or until vegetables are tender. Meanwhile, cook bacon until crisp.
Stir together flour and melted butter; stir into soup mixture. Cook and stir until slightly thickened and bubbly. Cook and stir 1 minute more.
Stir in whipping cream; heat through. Ladle into bowls. Sprinkle with cheese, bacon and green onions. Serve.