The waterpark represents a "shared resource". Every guest thinks their small amount of urine won't matter, but the cumulative effect destroys the park for everyone.
Aired in November 2009, "Pee" arrived five days after the release of Roland Emmerich's disaster epic 2012 .
Treading Yellow Water: Disaster Parody and Social Decay in "Pee" I. Introduction South Park - Season 13Eps14
The episode mirrors 2012 and other disaster films where a scientist’s ignored warning leads to a global (or park-wide) catastrophe.
Pi Pi, the park owner, prioritizes profit over safety, ignoring the "98% urine" threshold that triggers the disaster. IV. Satire of Racial Paranoia The waterpark represents a "shared resource"
The military’s subplot—believing the urine has caused a zombie-like mutation—parodies government incompetence. Their "vaccine" trials on monkeys (and eventually Stan's dad) ending in the discovery that bananas are the cure mocks the often-contrived resolutions of Hollywood thrillers. III. The Tragedy of the Commons
Through a gross-out premise of a urine-flooded waterpark, the episode satirizes the absurdity of the disaster film genre while providing a sharp critique of modern racial paranoia and the "Tragedy of the Commons." II. The Disaster Film Parody Treading Yellow Water: Disaster Parody and Social Decay
Cartman spends the episode panicking about the "minority" presence at the park, singing "Minorities at my Waterpark".