Why can't I wade in the pool?

For reasons of safety. The pool has many lights and sharp fountain heads that could injure visitors. 

How are the states arranged?

Much like a formal gathering of military or governmental leaders, wherein the guest or place of honor is at center. In this case, the place of honor is held by the field of gold stars that symbolizes the number of American dead and missing from World War II. To the right of the place of honor would be the next important element in rank, superiority, or designation, in this case, the State of Delaware, the first to ratify the U.S. Constitution. To the left of the center would be the second, in this case the Commonwealth of Pennsylvania. Then the order goes back and forth, or right and left, around the circle, much like a military procession, or march of States as each entered the Union. The States are followed by U.S. Territories, again in the order by which they became such, alternating right to left.