Waikato Regional Council is this December celebrating the 40<sup>th</sup> anniversary of the Waihou Valley Scheme (WVS) which provides crucial flood protection to the likes of Paeroa, Te Aroha and Thames, and allows around an extra 50,000 hectares of land to be farmed safely.
The WVS – which includes river and catchment management infrastructure worth almost $130 million – was commenced in 1972. It covers a catchment of approximately 220,000 hectares on the eastern side of the Hauraki Plains and Thames Valley, stretching from as far south as Putaruru to Thames in the north.
Since European settlement there have been a range of occasions when parts of the Hauraki Plains and Thames Valley was covered by a “vast inland sea” due to flooding. That lead to the development of a significant number of stopbanking works last century.
The WVS built on and significantly improved these flood protection assets, doubling the Waihou River floodway, which had become damaged after two major floods in the 1950s and 1960s. Regular flooding after 1972, including events in 1981 and 1985, reinforced the need for the WVS to be completed.
Mostly built between 1972 and 1995, the WVS now incorporates:
These major assets are delivering huge value to local communities, the region and the country, said Matamata-Piako councillor Phillip Legg and Thames-Coromandel councillor Simon Friar.
“Prior to the WVS being fully developed, we could expect 1981-level flooding in Paeroa, Te Aroha and Thames every five to 10 years,” said Cr Legg. “Now it takes a one-in-50 year event to cause significant flooding in those towns, protecting private property, urban businesses, and industry and agriculture generally.
“The floods experienced in 1981, 1985, 1987 and more recently with the severe weather bombs simply do not have the same consequences due the assets installed by the regional council.”
Cr Friar said the scheme’s support for farming in particular paid dividends for the local communities protected and the wider region. “The WVS – coupled with the adjoining Piako River Scheme - means a huge area of farmland is able to be farmed safely, providing a major economic boost for our region.
“Also, roads across the Hauraki Plains and the base of the Coromandel Ranges don’t get cut off like they did historically, a fact appreciated by locals and the large number of people with holiday homes on the Coromandel.”
River and catchment services operations manager Guy Russell said the WVS was the first scheme in New Zealand to use a “whole of catchment” approach.
“The works not only include flood protection but involve willow clearance from river channels, extensive river channel management and soil conservation works such as riparian fencing, land retirement and control of pests such as goats.
“All these combine to help us manage the flow of waterways and protect land from being eroded away in floods.”
Mr Russell said the regional council worked closely with the Hauraki and Thames-Coromandel district councils to manage drainage issues, while the Department of Conservation also carried out work to control goats in the area.
“The benefits delivered by the WVS complement the work of those provided by the councils and DOC and helps give us the best value for money from what we do.”