I was at Wahweap a few years ago and per the information from others who had been there recently and the BLM station in Big Water that year, the roads that you used to be able to drive to get to the short hike are now off-limits and the only way in is via the long hike. And on the day I went, it was a long 5 mile slog only to arrive when the light wasn't any good. Not my most productive trip.
Don't know if the rules have changed, but I get the feeling it's still the same now - one option, the long hiking one.
-m