Waikato Regional Council staff are due to assist in assessing the impacts of a massive slip of soil beside and across the Mangaokewa River near Te Kuiti.

The event has also prompted a reminder about potential slip hazards when catchments are heavily saturated with rain.

The slip on private farm land – estimated at involving between 10 and 20 hectares – occurred on Tuesday about seven kilometres east of the Mangoakewa Rd intersection with state highway 30, and about 20 kilometres upstream of Te Kuiti.

Waitomo District Council has been handling the response at a local level from roading and water supply perspectives.

At this stage, advice is that it's not expected that the incident will result in any sudden downstream flooding hazards as water is flowing past the slip area.

Masses of dirt and rock has fallen into the Mangaokewa River.

However, it's expected the river will be discoloured for some time.

Regional council staff will be assessing the slip, any potential hazards and what environmental remediation options are possible.

While such incidents are rare and the cause of the slip hasn't been definitively identified, regional council hazards team leader Rick Liefting says it's a good example of the increased risks the region faces when catchments are very saturated as they are at present.

'The risks of such incidents remain low. But the rainfall in the region over the last few months has been higher than in other recent years. March and April saw rainfall and river levels at their highest on record in places.

'Based on current forecast rainfall, we don't have any particular current concerns about river flooding or other rain-related hazards in the region.

'But, as this incident near Te Kuiti shows, we need to remain vigilant for hazards risks and their potential impacts on people, transport infrastructure and the environment. We were lucky that this slip occurred in a relatively remote area.”

On such events, the hazards team advises that if people come across a slip they should call 111 if it has caused or may cause an impact on people or property.

They should stay away from slips until assessed as safe. Slips in general should be reported to local councils.

'The hazards team will continue to monitor forecast and river levels closely and provide relevant advice to communities and emergency services on potential risks.

He also advised people to keep up to date with any weather warnings from MetService, and the regional council's website and Facebook page.