Making these hurdles are fun and easy! You just need 2 laundry baskets per hurdle and some kind of dowel or stick or broom handle to stick through the slats.
To play the water balloon obstacle race, you first need to fill up a bunch of water balloons and get a tablespoon (used to carry water balloons) for each person.
The object of the game is to get the most water balloons in the basket at the end by going over the hurdles. You can assign each player a balloon color in order to easily count at the end of the race. You could also set a timer so they are forced to run over the hurdles, making it a harder race than if they are allowed to walk it.