Published: 30 August 2022
Newly compiled data confirms consistent and heavy rainfall over the past four weeks which has caused significant slips and flooding across Lower Hutt.
Since 21 July, downpours have caused extensive slips onto Eastern Hutt Road in Stokes Valley and forced two homes to be evacuated. Hutt City Council has received (up to 22 August):
- 143 reports of slips, mostly onto roads and footpaths, with 15 onto private property; and
- 90 reports of flooding, mostly stormwater overflowing onto roads.
These reports are thought to be a low estimate as some incidents go unreported. Some get reported directly to contractors, or contractors find additional incidents as they go about their work.
Figures supplied by MetService show that last month 50% more rain fell in Lower Hutt than the July average. We have already experienced almost 2.4 times the usual rainfall for the entire month of August.
Average annual rainfall is 1206mm and Lower Hutt has already recorded 1321mm to 24 August 2022.
Mayor Campbell Barry said the amount and consistency of rainfall has been unprecedented and has led to the many issues experienced across the city.
"The weather over the past six weeks has been a stark reminder that climate change is now on our doorstep, with impacts right across our city. Staff and contractors have done an outstanding job in challenging conditions, working day and night to keep our communities safe," said Campbell Barry.
Hutt City Council’s Chief Executive, Jo Miller, said the run of rainfall events one after another had saturated the ground, destabilised hillsides and caused repeated flooding.
"We’ve prioritised our efforts to clear roads, contain slips and clear trees that have been in danger of coming down following the heavy rainfall. Slips that present a safety risk to people and main roads are dealt with first and other work on the transport network will be addressed when we can get to it.
"Most of our staff and contractors have never seen anything like this, especially over such a long period. It’s caused disruption for many residents, blocked roads, and traffic issues are an ongoing problem. The good news is that through a sustained effort by our staff and contractors, people can still move around the city. There are still significant travel delays for Stokes Valley residents.
"Welfare checks have been provided to families over the weekend where slips have impacted access to their properties.
"We will still need to get a further engineering assessment of the slip on the Wainuiomata Hill before any more permanent measures can be put in place.
"Due to the recent slips on Eastern Hutt Road, further engineering assessments are being undertaken as a priority. This will help to inform next steps for Eastern Hutt Road where one slip has closed the two southbound lanes from Stokes Valley heading towards Lower Hutt, and another has reduced a 300m section of the road down to one lane, controlled by traffic lights, north of the Stokes Valley roundabout."
Hutt City Council advises any remedial work on roads across the city is subject to weather conditions. Safety assessments are undertaken and engineering advice sought prior to any work on slips. The situation is constantly changing and people are urged to check for roading updates on the Council’s website and social media channels.
Further notes on rainfall: Based on data from 1981-2010, MetService advises that Lower Hutt’s average monthly rainfall for July is 168mm, and for August is 92mm. In July 2022, it recorded 253mm, and by 24 August Lower Hutt had recorded 221mm for this month. 121.4mm of that was from 18 - 20 August inclusive.