Partially cook the bacon. Add the celery and chopped onion; cook until tender, but not brown. Drain the clams, reserving the liquor; add water to make 4 cups. Add the remaining ingredients (except clams) to the bacon mixture; simmer 35 minutes. Blend 2 tablespoons flour with 2 tablespoons cold water to make smooth paste; stir into chowder. Cook until mixture comes to a boil. Add clams; heat through.