Flood protection within the Lake Taupo management zone is focused on the existing Lower Tongariro River Scheme and the Tauranga-Taupo River Scheme.
The Tauranga-Taupo River causes significant flooding in and around the settlements of Oruatua and Te Rangiita and on adjacent farmland. The River has a substantial hill country catchment and is highly dynamic with substantial gravel transport in floods. Recent changes in the river course have altered the balance of flood overflow and caused erosion and scour in some areas and gravel deposits in others.
The existing Tauranga-Taupo River flood protection scheme comprises stopbanks and bank protection. Proposed new works include maintaining the main channel, upgrade of flood protection works, drainage improvements in flood prone areas, clearing vegetation debris from the river course where practicable (including the State Highway Bridge) and addressing issues of stopbank maintenance and land use/cultivation with the respective landowners. The Tongariro River presents a number of management issues, relating principally to protection of Turangi township and adjacent land. A Natural Hazard Management Strategy document has been published and Taupo District Council has in recent years implemented erosion and flood protection works, and scoped planning provisions for controlling development in flood prone areas.
Existing Tongariro River flood protection comprises stopbanks. Under Project Watershed, it is proposed that additional work be done to extend, raise and improve the stopbanks.