Waikato Regional Council is gathering information on a second concerning erosionevent in the Pueto Stream catchment near Taupo after intense rain on Saturday.
The second incident appears linked to issues thought to have contributed to erosion in the first Pueto event earlier this month, said Upper Waikato-Taupo area manager Anne McLeod.
“This latest extensive erosion discoloured the Pueto Stream and the Waikato River.
“We are looking into exactly what has happened. Unfortunately, more erosion after the first incident was not unexpected given the soil type and climate patterns in the area.
“Until the area has stabilised and vegetation has been re-established the land will continue to be at a higher risk of erosion.”
Ms McLeod stressed the latest Pueto incident and two other recent events, at Pueto and Aratiatia, had occurred on pumice soils which can be particularly prone to sheet and gully erosion, even if the land is covered by vegetation. Also, any very heavy rain, as occurred at Pueto at the weekend, can cause erosion on land in general.
“So we want to establish as far as we can what’s happened, including the amount of rainfall that occurred and land management practices, and how they have contributed to the situation.”
Ms McLeod said the latest incident, coupled with the earlier ones, highlighted the need for careful planning to help avoid soils being washed away.
“The erosion at the sites underlines the need for farmers to take measures to help prevent erosion, especially at times of the year, such as spring and summer, when sudden downpours can occur when land is being worked on.”
While details of exactly what has happened in the incidents is still being checked, the erosion in the Pueto Stream catchment farm appears to have followed cultivation and crop establishment which has exposed loose soil. The Aratiatia incident is thought to have been a “reactivation” of erosion that was occurring previously.
“After the first two incidents, the council has been reinforcing the need for best practice land management principles when cultivating pumice soils given the types of downpours that can occur around Taupo. The latest incident further highlights our point.”
Land owners could help minimise erosion risks by limiting the area of ground disturbed at any one time rather than trying to do all of the work at once, she said.
“Property owners should also seek advice on such issues before they start work.”
Ms McLeod encouraged any local people who spot discoloured waterways in the area to phone the council on 0800 800 401, as this information would help the council in understanding the scale of the issues being caused by the erosion.