Source: Auckland Council
Auckland Council, Auckland Transport and other agencies that work in the emergency response and support field have been working with residents in the Glenesk Valley area of Piha over the last few months on the flood risk in their area.
This work has included reviewing the impacts of two significant flooding events earlier this year; preparing a flood risk report for the valley and individual reports for each property; speaking to people and groups that operate businesses, services and hold licences to operate on council land; and engaging with the wider community on its ability to respond during an emergency (lead by Auckland Emergency Management).
Flooding events and the Glenesk catchment
Following unusually heavy rain, two significant floods occurred in the Glenesk catchment area of Piha earlier this year (3 February and 28 April).
Craig Mcilroy, General Manager Healthy Waters, says the Glenesk catchment has been developed on since the 1940s, but given its position in a natural flood plain, the previous council started adding flood notations to the LIMs of some properties in 2000. Auckland Council has placed flood notations on all properties since 2009 so that buyers would be aware of the risks when purchasing their properties.
“Following the February and April floods, the council prepared a flooding assessment report and consideration of options.
“This report has been shared with homeowners and occupiers in the catchment area, impacted organisations or businesses, and local stakeholders,” says Craig.
In addition, the Waitakere Ranges Local Board and the council’s Auckland Emergency Management team started working with the Piha community on a community resilience plan. This has included three sessions for the whole community to attend.
The report summarises the recorded rainfall and modelled flow rates, depth and water levels associated with the two recent flooding events. Primarily, it is an assessment of each of the contributing factors to flood risk, bringing together information available to us today. While it also identifies a range of options for further consideration, no recommendations or decisions have been made by the council at this time.
This is a large catchment area (1,100 hectares) and is relatively steep. During rainfall events this creates large flows that exceed the existing stream capacity causing the Glenesk Valley to flood frequently with unsafe depths and water speed.
“By reviewing information from the recent events and engaging with property owners and occupiers in the area we have confirmed that there are 24 properties and 19 habitable floors (floor areas used for living purposes) that are subject to frequent flooding.
“An additional 31 properties have their access cut off in flooding events.
“Naturally this process of assessing each property personally with each home owner will take time. However, we are committed to doing this as thoroughly and transparently as possible,” says Craig.
Like in many small rural communities, there is no formal stormwater or wastewater network in this area other than rural road culverts.
Working with residents
We have held community engagement sessions for Glenesk Rd residents since the flooding events to discuss the report and the impact on their homes. The most recent was a community clinic on Saturday 13 October where residents were given an individual household property report with a detailed assessment of the habitable floor building risk (including house floor surveys) to provide specific assessments of safety risks to property in flooding.
Getting in touch with residents in communities like Piha, with its mix of permanent, tenanted and holiday residents can be difficult. We have visited properties, hand-delivered information, written to landlords or absentee property owners, sent emails, contacted people by phone and reached out via local networks.
If you feel that we haven’t been in touch with you, please email us or phone 09 301 0101 and ask to speak to the Healthy Waters Customer Service team.
No properties in Glenesk Road have been issued with a dangerous building notice under section 124 of the Building Act 2004. If the council found there were any buildings posing a danger our policy says that we will issue a dangerous building notice. Buildings issued with notices would not be allowed to be occupied by residents until made safe and sanitary.
“We have taken the unusual step in this situation to talk through the potential for issuing dangerous building notices with property owners and occupiers before completing the assessment that might result in a notice being applied,” says Steve Pearce, Manager Regulatory Compliance.
“We will continue to work through the medium and long-term options for these sites with individual property owners and leaseholders.
“It’s important to note that business owners should have plans in place to manage any safety considerations that apply to their business.
“These are difficult times for property owners, we recognise this, and we’re working with them as closely as possible. We’ve advised them to work with their insurers too,” says Steve.
As well as ensuring that a wide range of council representatives have been available at community events and visits (including people from Auckland Emergency Management, Healthy Waters, and regulatory, compliance and consents experts), we have had people from Waitemata District Health Board (for psychosocial support), Fire and Emergency New Zealand, Auckland Transport and EQC in attendance.
Piha Mill Camp
Piha Mill Camp is at the head of the Glenesk Valley and was purchased by Auckland Council in 2007 to secure access to the regional parkland and continue the long-standing tradition of the children’s camp.
“While it is disappointing that use of the camp, as we know it, may not be able to continue, public safety is paramount,” says Mark Bowater, Head of Park Services.
“It is important to note that the use of many of our parks has changed over time but their history has not been forgotten and management plan processes allow us to look at new ways of using parkland.
“There are still decisions to be made about the future of the site and with the Piha Stream running right through the property, it is important that flood risk is factored into this.
The decision to discontinue operations at the Piha Mill Camp sits with the operator of the camp who must consider the detailed flood assessment that has been carried out and the implications on their operation.
Piha Campground, which is situated further towards Piha Beach, is operated on council land under licence. Council staff are working with the campground operator on future plans for the site.
Read more about the Glenesk Road Flood Assessment in these frequently asked questions.