Don't enter and don't send them garbage either. If you can't in good conscience enter a proper print then don't do one at all. Instead write to the Mayor or town council and inform them of why you won't enter and why many others won't. It is a way to get free photos and it is their way of telling you they put no value on your photography, talent and skills.
Have you ever noticed they don't have contests asking contractors to build them free buildings for a prize?