There are endless possibilities with water. When I want to keep my kids busy so I can get things done, I’ll often give them a few bowls of water, cups, ladles, and a few other things. They can be occupied for an hour, just pouring water from one container to another, and experimenting with sinking and floating. It makes a mess, so it works best outside. Otherwise, I put down some towels and switch them out frequently. Hopefully they’ll keep the water contained more once they’re older :).
A cup of water and a paintbrush are all you need for outdoor painting that’s perfect for a hot day. They can “paint” concrete, wood, etc. with the water and watch it disappear as it dries in the sun.
Water can also be useful in other situations. When my son was a toddler, we were stuck waiting in the patient room at the doctor’s office for awhile. In an attempt to keep him occupied without breaking medical equipment, I turned the in-room sink on low and let him splash his hands in it.
Of course, there’s always the beach, a pool, a river, etc. My kids also love to play in the bathtub.
Where do your kids like to play with water?