It is possible to get your data back if you have been backing your iPhone up to your computer. If not, then it is more difficult.
If you have been backing it up, here are the steps to retrieve your data on a new or fixed iPhone:
- Plug your phone into your computer and open iTunes.
- Click on your device when it appears in the menu.
- Click restore back-up.
If you haven’t backed up your phone to your computer, you will need to download a third-party data retrieval tool, and this can have a cost attached. If your phone is water damaged, and you want to retrieve your data, it might be worth having the phone fixed by a certified technician, solving both your problems.