The agency that supplies water to most of Southern California has paid tens of millions of dollars since 2008 to exit risky and complex financial deals it made before the Great Recession hit. The Metropolitan Water District of Southern California entered two dozen interest-rate swap deals, which, in a convoluted way, aimed to stabilize debt interest rates, but amount to bets on the way interest rates will go. If interest rates move one direction, the swap becomes an asset. If they move the other direction, it becomes a liability.