The Tauranga-Taupo and Turangi Rivers near Lake Taupo have experienced very large floods estimated at a 100 year return period over the weekend.
Environment Waikato says flood control work on the Tauranga-Taupo river prevented even more severe damage than could have been expected with the magnitude of water flowing through them.
The peak flow was more than 300 cubic metres per second before the recorder was washed away – half as much again as in May last year when substantial damage was caused. The protection scheme on the river was almost complete with about six weeks’ work to go.
This time there was significantly less property damage.
The last flood where houses were inundated was in December 2001 and this flood was larger but caused less damage.
The completion of the project depends on approvals from property owners for some of the remaining work and has been slowed by wet weather throughout January and February.
Asset Management Group Manager Scott Fowlds said flood protection work on the Tongariro and Tauranga-Taupo rivers were a top priority under Project Watershed.
“We have given priority to these two major river operations. The Tauranga-Taupo was the highest priority in terms of level of risk and the work was virtually completed. We had completed some of the works on the Tongariro and they have worked successfully.”
Project Watershed funding for a 15 year project had only been finalised in November 2002 and the design was completed last year. The project had to be assessed for environmental effects before consent applications could be made.
He said the Tongariro River reached a flow of 1400 cubic metres per second at the height of the flood, compared with its normal flow of about 24 cubic metres – a major event for the works to deal with.
Work on both rivers is being given high priority to complete and the work on the Tongariro River is likely to be completed before the winter of 2005.