The Waitakaruru Stream is a major tributary of the Piako River, within the Waikato region of New Zealand's North Island.

The Waitakaruru Stream has its origin in the Te Miro-Tahuroa Hills south of Morrinsville, within the Waikato District.

The stream passes through the settlement of Motumaoho, progressively turning a more easterly direction towards Morrinsville, where it has a 1.8 km (1.1 mi) walkway beside it[1] and converges with the larger Piako River on southern outskirts of the town.

Parts of the middle catchment are prone to minor flooding due to a natural constriction in the stream channel between Eureka and Motumaoho.

[4][5] Near its source, in the Scotsman Valley area, the stream has short- and long-fin eels, common bully, torrentfish and koura.