I lived downtown last year for school, and I snowboarded there once. There were only a few other people there, and I went when we had less than 6 inches of snow. It got torn up pretty quick, and rocks starting popping out all over and I did not want to destroy my board so I left. Regardless, theres a teeny tiny small hill on the southeast end that leads to like a set of 4 or five stairs. But, it fails part b below:
It difficult to find a good spot where a) your allowed to snowboard and b) your snow isn't going to get walked all over by tourists.
I would add pictures, but I dont have them. sorry.