I haven't noticed much smoking in parks in the area. There's a small park right by me, I think at that one smoking may be legal - most parks there's a bylaw against it, but this one doesn't really have any of the amenities like a sports field. There's a few picnic tables, I have seen people playing cards and smoking/vaping fairly late. It's easy enough to keep enough distance to avoid being affected.
Lake, it's not allowed, I think there are likely some problems in the parking lot after hours, I do see teens head that way sometimes, they have also set off fireworks in the parking lot at night..
Another larger park with a parking lot is definitely more of a problem, again at night. There are always cars parked there, people smoking, drinking. Concerning with people driving plus we had a temporary community garden there, so a few of us were often cleaning up the site - broken glass, cannabis packing, food packing left there. It wasn't something happening during the day. I know people who lived across the street were concerned as no big surprise, people buying/selling/consuming drugs in the parking lot were also often up to no good in other ways. If I lived across the street, I would likely be discussing things with neighbours, calling bylaw often.