There are many causes of water disasters, some natural, some created by us. But in every situation it's important to know what we can do to prevent, prepare for, and survive wild water. My Great Challenge: Water flows downhill, so the challengers must use sandbags and retaining walls to divert as much of it as possible away from the houses in the valley below. In the Field: Zoey visits the Vancouver Science World to learn about how water moves from the ocean to the clouds and back again. She also discovers how flooding can occur when there's TOO MUCH water.