Upper Thames River Conservation Authority says repairs and reinstallation of the south sluicegate at the R. Thomas Orr Dam are complete.
The dam on the Avon River is a tributary to the North Thames River and a focal point for residents and visitors to the city.
The conservation authority says the structure consists of two gated spillways and a duck-bill shaped overflow weir.
Each sluicegate is about 14-feet tall and 24-feet wide, and weighs more than 10.5 tonnes.
A review recommended repair and the gate was moved in January.
Similar repairs to the North sluicegate will start once funding is acquired.