I don't know what it is about water...but my kids LOVE any activity that involves playing with it! I love it too, because it's free (or cheap anyway) and even if it makes a mess, it just dries right up!
Here are some of our favorite things to do with water:
1. Washing dishes - I put some plastic silverware and dishes in the sink with some water and a tiny bit of soap and let them have at it! Plus it's good practice for the real thing later on!
2. Sink or float - fill a bucket or Tupperware container with water and find household objects (that you don't mind getting wet) to test if they sink or float. Make predictions before you try each object. Great way to incorporate science!
3. Paint with water - get paint brushes and a cup of water and paint the sidewalk or fence! You can make it educational by having kids write their name, sight words, or even try math problems - get the answer before it dries up :-)
4. Play with ice - one of our favorites during the summer! (Do your kids ALWAYS want to play with the ice in their cups at restaurants...or is it just mine?) Dump some ice on the ground and play with it! Try stomping on it, writing with it, or doing some melting experiments (different sizes, different places, sun vs. shade, etc.)
5. Pouring fun - sometimes I just grab some cups and different size plastic containers and put them outside with a bucket of water. Pouring water between containers is somehow very satisfying for little ones.
6. Have a car wash - my son especially loves this! Set up a car wash with some soapy water and towels, and let the kids drive their matchbox cars through! We also added our car ramp next to it so the cars could come splashing down.
7. Make a Boat - give them some aluminum foil and have them try to fold it into a boat that will float on the water. Use washers or marbles to see which boat can hold the most without sinking!
8. Water Races - set up each person (or team if you've got a lot of kids) with 2 containers - one filled with water and something to scoop with and the other across the yard. Have a relay to see who can get all the water from one container to the next, one scoop at a time! You could also use a big sponge to transfer water instead of scooping it!
9. Set up a marble tower and pour water through it! My toddlers always want to put those pesky marbles in their mouths, so this is a super fun way we can still make use of the tower. (Fun for bathtime too!)
10. Another one for summer - freeze some small objects/toys in a big block of ice, or individually in ice cubes, then let the kids play with it outside until it melts enough to get the toys out! You can use some warm water to pour over it to speed up the process if needed!