Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search


Explosives release water from dam at Mangapoike River

Explosives release water from dam at Mangapoike River landslide

Explosives were detonated yesterday to cut a two-metre deep trench to release water from a dam formed by a Mangapoike River landslide.

The landslide was likely triggered by a small earthquake in the area earlier this month, resulting in the formation of a dam which was more than 40 metres deep and rising 60cm a day.

With rainfall predicted over Easter, there was a high risk water levels would rise and potentially damage a bridge at Paparatu and block access to Mangapoike Station.

Council’s principal scientist Dr Murry Cave says if that were to happen over the long weekend, there was less ability to respond rapidly.

“Council identified a window to give nature a hand before Easter and undertook the blasting operation to allow for a controlled release of water from the dam into the basin behind it,” he says.

Council staff have been working with Hawke’s Bay Regional Council and scientists from Auckland University to monitor the landslide.

Their assessments led to the conclusion that if a channel was cut between the lake and a low point in the dam, there was a good chance the water levels could be safely reduced.

“This operation was completed successfully with overall water levels dropping giving Gisborne, Wairoa and Hawkes Bay councils time to plan for a spillway on the downstream side of the spillway if this should be necessary,” Dr Cave says.

A video of the explosion can be found on the GDC Facebook page.

Council will continue to monitor the situation over the next few weeks until the long-term stability of the dam is established and lake water level stabilizes to a point that eliminates the risk to Mangapoike Station.

The area affected by the landslide is now approximately 33 hectares.

Paparatu Road was closed to the public last week.


© Scoop Media

Parliament Headlines | Politics Headlines | Regional Headlines

Gordon Campbell: On The (Delayed) Judgment Day For Theresa May

When under stress, British PM Theresa May reportedly eats peanut butter straight from the jar.

Crunch time is looming on Tuesday night in Britain, amid every sign that May’s compromise deal for Brexit is headed for a heavy defeat... More>>


Conflicts, Inadequacies: IPCA Finds Police Investigation Flawed

The Independent Police Conduct Authority has found that a Police investigation into inappropriate contact between a teacher and a student in Gisborne in 2014 was deficient in several respects. More>>


PM's Press Conference Multimedia: Grace Millane, ACC Levy Hold, Absent Execs

Prime Minister Jacinda Ardern began her Monday post-cabinet press conference with an emotional comment on the murder of English backpacker Grace Millane. More>>


Child Poverty Monitor: Food Poverty Due To Inadequate Income, Housing Cost

The latest Child Poverty Monitor released today by the Office of the Children’s Commissioner reveals alarming facts about children suffering the impacts of family income inadequacy, says Child Poverty Action Group (CPAG). More>>


Open Government: Proactively Release Of Ministerial Diaries

All Government Ministers will for the first time release details of their internal and external meetings, Minister for State Services (Open Government) Chris Hipkins announced today. More>>


Billion Trees: Questions Over Shanes Jones Carbon Claims

“Officials estimate the actual value of the One Billion Trees (OBT) scheme will be just a third of the amount Mr Jones claimed, at about $900 million, and that he padded the number by including $800 million of ETS benefits and $1 billion of business-as-usual activity..." More>>

'Sovereignty Concerns': Plans To Sign UN Migration Pact

New Zealand is likely going to sign up to a United Nations migration pact this week as long as it can iron out a concern around sovereignty. More>>


Most Vulnerable Face Most Risk: Sea Level Rise Threatens Major Infrastructure

The burden of sea-level rise will weigh on the most vulnerable unless a new approach is developed and legislated, a new report says. More>>


Gordon Campbell: On The Pope Of Parliament

’Tis the season of goodwill towards all humankind… except it would seem, towards the Speaker of Parliament... More>>





InfoPages News Channels