What event does Leslie revive to save Pawnee's Parks Department?

Leslie revives Pawnee’s Harvest Festival to save the Parks Department.

The festival is the central project of the third season’s opening storyline. Pawnee is facing severe budget problems, and the Parks Department is threatened with elimination. Leslie makes a high-stakes agreement: if the revived festival succeeds, the department can survive; if it fails, its future is in danger.

The event brings together the department’s staff and many Pawnee residents. Its obstacles include a supposed Wamapoke curse, difficult local media coverage, and the disappearance of Li’l Sebastian, Pawnee’s beloved miniature horse. Leslie’s persistence ultimately helps turn the festival into a major success.

The dedicated episode, also titled "Harvest Festival," is the seventh episode of season three and the 37th episode overall. It originally aired on March 17, 2011. The festival had previously been a Pawnee tradition before ending, so its revival connects the town’s past with Leslie’s campaign to protect public services.