Melt butter in 5 to 6 quart dutch oven over medium-high heat.
Cook onions, celery, bell pepper, garlic and chicken in butter 7 to 9 minutes, stirring frequently, until onion is softened and chicken is no longer pink in the center.
Stir in flour.
Cook 5 to 6 minutes, stirring constantly, until flour is light brown.
Stir in remaining ingredients except rice and water.
Heat to boiling; reduce heat to medium low.
Cover and cook 25 to 30 minutes, stirring occasionally, until chicken is tender.
Meanwhile, cook rice in water as directed on package; stir cooked rice into soup.