In a competition to woo students, public universities are increasingly offering lavish amenities that have nothing to do with education.

The latest trend is lazy rivers, which have been installed at several big institutions, including the Universities of Alabama, Iowa and Missouri. Last year, Louisiana State University topped them all with a 536-foot-long “leisure” river in the shape of the letters “LSU,” part of an $85 million renovation and expansion of its gym. It was L.S.U. students who footed the bill.

At a time when college has never been more expensive, this is the last thing students should be paying for. According to the College Board, tuition and fees at public four-year institutions grew more than 60 percent over the past 10 years. State budgets for higher education have been slashed, and students have to make up the difference.

In the case of L.S.U., the lazy river was financed entirely by student fees, an addendum to their annual tuition. According to the Chronicle of Higher Education, over the past five years, those fees increased by 60 percent, nearly triple the amount L.S.U. students paid in 2000.