They certainly are cute. Please add your location to your profile because it helps with giving advice.
1" chicken wire will do nothing to stop predators. In my area the main ones would be fox and raccoons. A pair of fox ran through my yard this morning at 9:30. The only birds I have ever lost to predators have been daytime attacks. I hope their run is close enough that you will be able to hear a commotion if an attack occurs. These predators are fast.
Also please use the Search function on this site to learn about ducklings, water and swimming. Without functioning oil glands yet or a mother duck, ducklings can become waterlogged.
If you are thinking of ramps, they aren't really duck things like chickens. Ramps need sides so they don't fall off and hurt themselves. Instead I used large rocks inside and outside of my ducks kiddie pool so they can easily climb in and out.