Rotorua lake levels: Rafting companies say high lake levels are impacting business

Two rafting companies believe they and others have collectively lost at least $1 million as high flows keep them off Kaituna River.

One of them, Rotorua Rafting, has been forced to close for hundreds of days in the past year and fears nothing will change soon with winter here.

Rotorua's lakes are higher than they have been in decades as heavy rain and cyclones battered the district over the past year. The impacts have been widespread.

Among those suffering were businesses in the adventure tourism sector. Rafting companies that called the Kaituna River home had not been able to use the natural asset as the amount of water coming down was nearing double what they had consent to raft on.

The river is fed by water from Lake Rotoiti and passes through the Okere Arm control gates, built in 1982 to regulate the water flow. The nearby Ōhau Channel Control Structure was built seven years later to control water level fluctuations in Lake Rotorua.

But as lake levels remained high, the gates remained open.

Along with algal blooms and heavy rain stopping businesses, Rotorua Rafting owner Sam Sutton said the collective loss of income from rafting companies using the river would have hit at least seven figures.

Among other factors, the river was only able to be used for rafting when its flow was under 26.5 cumecs - one cumec is a cubic metre of water flowing past a point in one second.

It was sitting at 42 cumecs on Monday, according to Bay of Plenty Regional Council.

As a result of the blooms, rain, and water flow, Sutton said the business had been closed about 270 days between May 2022 and May 2023.

He hoped the coming summer would be better than the last.

"It was ridiculously wet.

"I'd like to see any business try see only 100 days open."

Sutton said he had raised the idea with the regional council of opening the gates at night to allow commercial activity during the day, but he was told it could cause river banks to fail with sheer amounts of water coming through.

He believed this was based on global information and wanted a local investigation undertaken to study what the impact would be.

Kaituna Cascades Rafting Company co-owner Pete Lodge supported this idea.

"It's been really bad and it's not looking like it's getting any better with winter and the rains upon us at the moment."

To keep the business going and staff employed, guests were being taken to Rangitaiki River. But Lodge said this was not economically sustainable.

Covid-19 was challenging, he said, but the current situation was even worse with the administration of making bookings, rescheduling, refunding or planning alternatives.

"You're doing triple the work for not making any money."

He agreed with Sutton on the estimated combined income loss of $1m.

Things could become "really bad" if this continued, he said. He hoped climate cycles would shift to allow for a drier summer. He believed it would take a month of no rain to get back to levels for rafting.

The Kaituna was slightly different to other rivers for rafting. Lodge said low levels were good because they increased the drop from the waterfalls that people came from over the globe to experience.

"The river is just a playground when it is low."

Rafting as it was now could result in injury, including being dragged back into the waterfall, he said.

Toi Moana Bay of Plenty Regional Council provided to Local Democracy Reporting the number of commercially operable rafting days, with only 58 out of 157 this year up to 8 June.

It said the water flow was 51 cumecs in February following Cyclone Gabrielle.

Engineering manager Mark Townsend said winter usually saw a natural fluctuation of lake levels, however a wet summer and multiple cyclones made them higher still.

Climate change would likely make these extreme weather events more common, he said.

A consent requirement was that the flow through the Ōkere gates should always be greater than the flow through the Ōhau channel to stop reflux into Lake Rotoiti.

Townsend said when lake levels were high, the weir/gates were opened to relieve those lake levels to prevent flooding and erosion of lakeside properties.

Conversely, when the lakes are low, the structure outlets were closed to reduce outflows and preserve lake levels.

In response to Sutton's idea of night-time control, Townsend said the council aimed to monitor and understand flood risks, manage environmental protection, and address community concerns.

"Unfortunately, opening the gates only at night is not a possibility, due to the consent requirement explained above, and because frequent fluctuations in river levels and flows exacerbate river bank erosion downstream."

He said it would lead to river bank failure, expensive repairs, and further issues for the environment, plant and aquatic life, and river users.

"The issue of fluctuating flows is a well-known issue that we manage across our rohe on a constant basis."

Others in the community have said they want to see the gates open fully on a more permanent basis to address the high water levels.

This idea was recently brought up at a Rotoehu and Rotomā community meeting to tackle short-term solutions to lake-level issues.

Townsend said the consent for Lake Rotorua was in place to manage lake levels. The consent for Rotoiti was primarily to preserve water quality but also had conditions to manage lake levels.

"Each lake has its own operating range with maximum and minimum levels, these are only achievable outside of extreme weather events."

He said it balanced the needs of the community, which included protecting properties and the environment while acknowledging the natural variability of the lakes.

"Managing lake levels is a complex task centred around managing flood risk, environmental protection, and recreational opportunities."

The conditions of the consent can only vary through a consent review process. The consent was renewed in 2012, reviewed in 2020 and runs for 35 years.

Local Democracy Reporting is Public Interest Journalism funded through NZ On Air