Havelock North cyclone flooding: Ombudsman chides Hastings District Council for stream and dam maintenance failures

The Mangarau Stream in Havelock North swelled during Cyclone Gabrielle, flooding more than 30 homes. Photo / NZME

The Chief Ombudsman has chided Hastings District Council for its failure to maintain dams above Havelock North and to clear village streams of debris before Cyclone Gabrielle.

In a report released on Monday, Peter Boshier said the council had not acted for years despite concern from engineering consultants Stantec, which conducted annual checks of the dams, where it noted failure of the dams would cause significant damage and could result in fatalities.

During the cyclone in February 2023, floodwaters swept through more than 30 properties in Havelock North. Thirty-eight properties bordering the Mangarau Stream in Havelock North are still categorised as 2C, meaning the properties are waiting on planned flood protection solutions.

After the cyclone, Jessica Maxwell complained to the Ombudsman arguing the council had neglected the Mangarau dam and stream, as well as the Herehere dam and stream, and had failed to carry out dam improvements recommended by engineers, and that this had contributed to the flooding.

A report in late 2023 found there was a misunderstanding for 20 years around who was responsible for maintenance of the five dams, designed in the late 1970s, and the clearing of the streams.

Boshier said there was “no basis for me to reliably conclude that the district council’s alleged omissions, relating to the Havelock North dams and waterways, caused or contributed to the post-cyclone flooding in the area”.

The council said Cyclone Gabrielle was a one-in-250-year storm, at least, and although all the dams were rated to take water from a one-in-100-year storm, they held up quite well.

During Cyclone Gabrielle, 238.5mm of rain was recorded in the Mangarau Dam in a 24-hour period.

“It is arguable that Cyclone Gabrielle was so severe that irrespective of the state of the dams and waterways, the flooding and resultant damage could have occurred regardless, given the amount of rain that fell in the area over this time,” Boshier said.

Despite this, the council’s omissions to maintain the dams and the Mangarau Stream were unreasonable given reviews it had received in 2016 and 2021, the Ombudsman said.

Chief Ombudsman Peter Boshier. Photo / RNZ, Dom Thomas

The 2016 review indicated that the council’s highest priorities should be to look at flood capacity improvements to the dams, Boshier said, but instead it had prioritised “work in Te Awanga and Clifton during this period”.

The 2021 review again highlighted concerns about the capacity of the dams, and recommended the council carry out a high-level assessment, with a priority of a one-year timescale. This was not done before Cyclone Gabrielle.

The council told Boshier the dams were not deficient and were not categorised as flood-prone or dangerous. Under legislation, they did not require the urgent review that was recommended.

“Notwithstanding the district council’s explanation ... council did not properly address this issue at the relevant time, when it should have done so,” Boshier said.

He said he was also surprised an emergency action plan (EAP) for the dams had not been created, despite multiple recommendations.

Darcy Turner took this photo of flooding on the Mangarau stream during Cyclone Gabrielle.

“It should not take an extreme weather event for the district council to implement recommendations that should have been adopted earlier.

“I am particularly disappointed that the district council did not have in place an EAP for the dams.

“Such a plan is critical because it impacts on the community’s safety during a major flooding event.

“The district council has indicated that even if an EAP was in place at the time of Cyclone Gabrielle it may not have been fit for purpose given the severity of the storm. I do not accept this as a justification for the district council’s omission.

“In reviewing many years of professional observations and safety reports for the Havelock North dams, a pattern of behaviour has emerged that shows the district council failing to action certain recommendations regarding the maintenance of the dams.”

Jessica Maxwell holds the Ombudsman's response to her complaint about Hastings District Council.

Boshier was also critical of the council for claiming in Hawke’s Bay Today, in a response to a letter to the editor from Maxwell, that the Mangarau Stream had been cleared before the cyclone when it had not been.

He recommended the council publicly correct the statement, which it had agreed to do.

The council “fell short of its responsibilities, and its omissions to clear the Mangarau Stream closer to the time that debris in the stream were reported to it, were unreasonable”, he said.

He noted the council’s management of the streams and dams post-cyclone had improved and it had committed to a programme of improvements, so he did not make a formal recommendation.

Hastings District Council welcomed the report from Boshier and said: “It is of note that the Ombudsman found that given Cyclone Gabrielle was a significant event and two and a half times greater than the 100-year event the dams were designed for in the late 1970s, it could not be concluded that the impacts could have been mitigated had any further actions been undertaken by council.

“However, council agrees that over the decades it has not had the focus on the dams and streams and their maintenance that it could have.

“Council is committed to improving its management and maintenance of the Havelock North dams and streams, particularly given the outlook is for such extreme weather events to occur more regularly as a result of climate change.”

The council also released a list of the 68 actions it had undertaken, or was undertaking, related to the streams and dams, which can be read on its website.

Maxwell said Boshier’s report was a “humiliating loss of face” for the council. She said her complaint had been endorsed by a petition of 60 flood-affected residents who had asked for it to be prioritised.

She said council leadership needed to “fall on their swords and resign in disgrace. The sooner the better”.