I did wild wadi during ramadan last year so it was definitely open! I don't remember any restrictions on water in the park either, but technically Muslims shouldn't be in there anyway as many more religious people I know would consider getting water in your mouth from tghe spray on a water slide to be breaking the fast so most wouldn't risk it.
Alcohol is banned before sunset, and as this changes by 4 mins each day they usually set a time - last year was 7:30pm before anywhere could serve it.
Stay off the roads as much as possible in the hour before Iftar - its crazy!
Remember chewing gum and smoking in public are banned in daylight hours too - easy ones to forget, as well as drinking water in vehicles because you are still technically in public.
And one key thing I tell anyone visiting during Ramadan - just because you see someone else doing something you think might be wrong - don't do it yourself. Plenty of people flout the rules, and plenty of people get away with it. Is it worth that risk? I know many people (and not just friend of friend type stories) who have been fined for breaking the rules.
Offices will close early, as the working day is limited to 6 hours. Some offices will let you carry on as normal in the office even though they''re not supposed to and all offices expect mine will have somewhere you can go for a brew and some water during the day.
When you leave the pool to go up to your room especially if you're getting towards sunset and therefore lots of Muslims will be arriving at hotels for Iftar, make sure you cover up better than you normally would even for Dubai. Make sure anything you put over your bikini for walking through the lobby isn't too sheer or strapless. No point risking offence if its easy to avoid!