A government initiative for Lake Rotoiti is being hailed a success by the Minister for the Environment.

Nick Smith says the Ohau Channel Diversion Wall in Lake Rotoiti is proving a huge success by diverting nutrients from Lake Rotorua and improving the water quality.

He says that while it's still early days, the clarity of Lake Rotoiti has improved greatly since the diversion wall was completed in 2008.

Although neighbouring Lake Rotorua has had algal blooms since the wall was erected, they haven't appeared in Lake Rotoiti, with the nutrient flow going directly down the Kaituna River.

During a visit to the lakes this week, the Minister recognised the importance of the lakes to Te Arawa, and for New Zealand tourism.

Mr Smith says the Government's commitment to the area is shown through the $4 million contribution to the wall, and another $72.1 million to restore four of the most degraded of the Rotorua lakes.