MIX 1 can of the chicken broth, the onion, carrot and celery in large saucepan. Bring to boil on medium-high heat. Cook 5 to 10 min. or until vegetables are crisp-tender, stirring occasionally.
STIR in squash, rice and nutmeg. Add remaining can of broth and the water. Reduce heat to medium; cook 10 to 15 min. or until squash is tender, stirring occasionally.
POUR soup in batches into blender container or food processor container fitted with steel blade; cover. Blend until pureed. Return to saucepan; stir in milk. Cook on low heat until heated through, stirring occasionally.