The reward can book an interview in name of the winner to apply for an internship. The opportunity to get an internship position will result as an excellent experience and it is priceless.
There is always things to do that takes a lot of time of the professionals and sometimes these time consuming tasks does not require much of a qualification in the field. However at least, an intern can spend time with like minded people and gain insight of the city planning, community services, transportation management, housing, councils and many different sorts of area that can contribute the cities becoming smarter.