Around here, when bridges become popular for jumping, signs are posted to notify people it is not allowed. So the bridge is public, the water is public, but from the professional body retrievers, the jumping is not legal. The assumption should be that it is not. The actual answer to your question probably depends on the specific bridge in question, and may vary from bridge to bridge.
justtysen had some excellent advice above. If you want to do it legally, be completely open about it, but also make sure the people you contact will see you as a responsible adventurer, and not someone looking for a thrill that may end up costing the city thousands of dollars in rescue and retrieval.
If you get away with it on the day-of, your video will likely lead to an arrest later.
Don’t ask a cop. Cops are not lawyers. If it’s a known statute, they can give you an easy ‘no’ but if it’s not a well-known law, they’ll probably say ‘no’ anyway but they may not be sure. If you really want to know the legality, be prepared to pay a lawyer to research your options for you. This is a lot cheaper than needing a lawyer later so it might be worth looking into.
I think when stuff like this happens on an “official” basis, permits are usually involved. Though I don’t imagine this is the way you want to go, it would at least ensure the jump was legal.
[QUOTE=wickedbobI’m planning on getting out of there quick, but at the location I’d like to do it, I fear the cops will get their quicker, and I’m not going to run from the police.[/QUOTE]
Aw, c’mon. We’ll never see you on COPS if you don’t run! Consider your exit plan from your landing site. Then consider your exit plan if you’ve taken a bad landing. Planning to swim to the side? Have someone else in the water just in case.
And if you haven’t tried something like this before, you definitely don’t want to start at 70’. The highest jump I’ve done into water is about 30’, and it was a surprising amount of freefall for that. Work your way up.