the 5 o'clock wave is a fictional theory on the reasons for wagga wagga's sporting success. according to the local urban myth, at precisely 5 o'clock arrives a giant wave which flushes a secret nutrient into the murrumbidgee river following the release of water from the blowering and burrinjuck dams. the wave is said to continue down river at high speed, and indeed visitors are told it is so powerful that surfers can ride it along the meandering river until it reaches the town of narrandera.