Rotorua Lakes Restoration Project

Lake Rotorua

Green is not always good. In lakes around the Rotorua region, the water can become almost tennis ball-green, the result of toxic algae. This is caused by increasing nitrogen and phosphorous loads, from land-use in the catchment.

A strategy to restore and protect the Rotorua lakes has been developed by Environment Bay of Plenty, with strategic partners Te Arawa Maori Trust Board, and the Rotorua District Council. The Rotorua Lakes Proteection and Restoration Programme (with an estimated $190 million cost) has the vision to restore and protect the water quality of the lakes. Environment Bay of Plenty is leading the techical projects required to achieve nutrient reduction and remediation of lake water quality.

Rotorua sampling

GNS Science is involved as a project partner - to define and understand the groundwater catchment of Lake Rotorua. GNS Science expertise in this project includes geologists, hydrologists, geochemists, water dating and field staff. Environment Bay of Plenty are the project managers and have provided much of the field work support, while GNS Science have assisted in interpreting and building on the data. We have also developed a 3D computer model of the entire Rotorua catchment, and used isotopic techniques to model future nutrient loads into the lake.

Knowing the extent of characteristics such as flow rates and length of water residence time of the catchment is vital to support decisions for remediation actions to restore lake water quality.

Contact: Paul White