Ohau diversion wall

The Ohau Diversion Wall was constructed in 2008 to improve the water quality in Lake Rotoiti.

Seventy percent of the nutrients reaching Lake Rotoiti came from Lake Rotorua via the Ohau Channel. The Wall stops these waters entering Lake Rotoiti and sends them down the Kaituna River. So far this action has been successful in protecting the lake.

The Wall has given us time to reduce the nutrients in Lake Rotorua and enjoy improved water quality in Lake Rotoiti.

A Lake Rotoiti Fish Monitoring Programme undertakes research to determine if the Wall has an impact on fisheries in Lakes Rotoiti and Rotorua.

Wall Facts

  • is a sheet pile wall 1300 metres long

  • attached to the lakebed with king piles up to 70 metres deep

  • has a low profile which only extends 500 millimetres above the water surface

  • expected lifespan of the wall is more than 50 years.