Tarawera Sewerage Scheme
Lake Tarawera’s water quality is dropping and wastewater from septic tanks, which leaches through groundwater into the lake, is a contributing factor.
Homeowner's Manual - Pressure Sewerage System - (PDF, 1.8MB)
EcoFlow E-One - Alarm, Onsite System and Toilet Stickers - (PDF, 66KB)
How the Scheme Developed
The Tarawera Lakes Restoration Plan was adopted in 2015 by the Rotorua Te Arawa Lakes Strategy Group – the governing body for the Rotorua Te Arawa Lakes Programme.*
It was developed in collaboration with the community and sets out actions for that catchment (8 lakes) to protect water quality and public health, backed by scientific research and advice.
Actions in the plan include reticulation. Other actions have already been fully implemented, including farm management across all of the nine contributing catchments.
In 2015, at the request of Tarawera residents, Rotorua Lakes Council (RLC), Bay of Plenty Regional Council (BOPRC), the Te Arawa Lakes Trust (TALT) and the community began exploring options for reticulation.
This followed the adoption of the Tarawera Lakes Restoration Plan by the Rotorua Te Arawa Lakes Strategy Group after collaboration with the community.
A community-led steering committee was set up, including representatives from Tūhourangi Tribal Authority, Te Mana o Ngāti Rangitihi, Māori landowners, Lake Tarawera Ratepayers Association, TALT, BOPRC and RLC.
In 2018, having considered various options, the committee recommended installation of low-pressure grinder pumps on properties and connecting these to a new reticulated sewerage system that would, in turn, connect to Rotorua’s main treatment plant via Tarawera Road. The record from the Steering Committee indicates that all voted in favour of this option.
The options presented to the Lake Tarawera Sewerage Steering Committee were:
- Treatment plant at Tarawera
- Low pressure grinder pumps + connect to Rotorua through the road
- Low pressure grinder pumps + connect to Rotorua across Playne’s Farm
- STEP pumps + connect to Rotorua through the road
- STEP pumps + connect to Rotorua across Playne’s Farm
Option 2 (low-pressure grinder pumps and to connect to Rotorua through the Tarawera Road corridor) was adopted because:
- It ensures all properties comply with Bay of Plenty Regional Council regulations
- It's the most cost-effective option for homeowners
- Supports mana whenua aspirations to return to Tarawera for settlement
- Avoids identified wāhi tupuna sites
- Can be implemented quickly as resource consents not required
- Is the most effective option to address the Lake Tarawera water quality risk.
Arriving at the preferred option followed careful and balanced consideration of all relevant factors including technical, cultural, financial and planning.
Two Cultural Impact Assessments (CIAs) and an Archaeological Report were also commissioned.
The CIAs, undertaken by iwi, considered the cultural impacts from the proposed preferred option and indicated some opposition to the pipeline route. The archaeological report noted that previous modifications on the road corridor had significantly reduced the likelihood of the presence of significant archaeological features in the path of the pipeline.
RLC adopted the project as a draft in 2020 and undertook community consultation as part of the 2021 – 2031 Long-term Plan (LTP). No objection to the project was raised and Council approved funding for the preferred option.
*The Rotorua Te Arawa Lakes Programme is a partnership between BOPRC, RLC and Te Arawa Lakes Trust (TALT).
Modern Standards for On-Site Effluent Systems
Septic tanks do not meet modern standards for effluent disposal in sensitive lake catchments.
There are about 169 dwellings at Tarawera where on-site treatment and disposal systems that would meet required modern standards for on-site systems could not be installed, due to site constraints like soil type and topography.
This was established by site visits to about 30% of the dwellings at Tarawera and desktop analysis to determine the rest.
The BOPRC Regional Plan does not support on-site effluent systems where connection to a reticulated network is available. Additionally, anyone wanting to continue with an on-site system would need resource consent and any such application would require RLC support, which would not be given where connection to reticulation is available and technically feasible.
Properties with consented on-site systems will be required to connect to reticulation or apply for consent to continue with an on- site system when their current consent expires.
There are existing unconsented septic tank systems at Tarawera that don’t comply with the Regional Plan, but BOPRC has not actively enforced the requirement to upgrade these given reticulation is to become available.
Estimated Impact of Septic Tanks
If we don’t replace the septic tanks with a reticulated system, we estimate about 200,000 - 300,000 litres of untreated sewerage a day will continue to seep into the ground and pollute Lake Tarawera.
The estimate is based on the average water usage of 700 litres per day per household, with around 450 households in Tarawera. We also account for lower occupancy periods, resulting in an average estimate of 252,000 litres per day.
This is the approximate number of homes that will be connecting to the reticulation scheme, based on our rating database. The 20% reduction that is factored in is also an estimate as the council does not hold data on how many homes are occupied full-time, part-time or are rented out as holiday accommodation.
Here is the calculation the estimated figures are based on:
- Approx. 450 households
- Average water consumption per household (industry estimate) of 700 litres per day
- We have reduced the number of households by 20% to allow for water used outside and some properties not being permanently occupied
- 450 x 700 x 0.8 = 252,000 average.
- There will be fluctuations, i.e. lower during quiet periods of occupancy and higher during busy holiday periods.
Lake Rotokākahi
Pipeline information
Injunction Order and Environment Court Applications
Works on pipework installation under Tarawera Road started in May 2023 but paused in 2024 following obstruction by protesters near Lake Rotokākahiand to allow further engagement with iwi and mana whenua.
To ensure the safety of contractors and work sites and avoid further delays that could impact the health of the lake and would have cost implications for the community, council applied for an injunction so works could continue safely.
The injunction, which was granted in the Rotorua District Court in November 2024, prevents anyone from obstructing or interfering with the installation of the pipeline along Tarawera Road or entering the work zone without authorisation from the council or its contractors.
Work on the project resumed on February 24, 2025. On February 28, the Environment Court accepted Rotorua Lakes Council’s undertaking to pause work while it considered three applications filed in relation to the work.
An Environment Court hearing was on March 19, 2025 before Judge Laurie Newhook relating to three applications, filed by the Rotokākahi Board of Control and Rotokākahi Protection Incorporated, relating to the final section of Stage 1 of the Tarawera Sewerage Scheme.
The Environment Court dismissed the applications in a decision released on April 1. 2025.
In dismissing the applications, the Environment Court found there had been extensive consideration of options for the scheme since 2018 and considerable attempts by the council between 2020 and 2023 to engage with iwi and mana whenua as well as offer mitigations to their concerns.
The Rotokākahi Board of Control has lodged an appeal against the Environment Court decision and lodged an application for a judicial review with the High Court.
Timeline: 2015- 2025
| June 27 , 2025 | Rotorua Lakes Council decides to commit more funding to the Tarawera Sewerage Scheme after securing an extra $2m in external grants, reducing the amount to be paid by Tarawera ratepayers.The decision brings the per property contribution of Tarawera ratepayers down from $46,705 (GST incl) under the previous (May) decision to $36,600 (GST incl), payable over 25 years. |
June, 2025 | Rotorua Lakes Council confirms the cost of the Tarawera Sewerage Scheme for Tarawera ratepayers following Annual Plan decisions last week. The per-property cost for Tarawera ratepayers has been fixed at $46,700 (including GST) which property owners will have the option of paying as a full one-off payment, or over 25 years through annual payments of $3,619, or quarterly payments of $905. |
May,2025 | Stage 1 of the Tarawera Sewerage Scheme is now complete and the first homes are expected to be connected by the end of June. Stage 1 included the installation of pump stations and the main network pipeline. Testing will be undertaken before homes can be connected. |
April 2025 | The Environment Court dismisses applications filed against Rotorua Lakes Council in relation to the Tarawera Sewerage Scheme. In dismissing the applications, the Environment Court found there had been extensive consideration of options for the and considerable attempts by the council between 2020 and 2023 to engage with iwi and mana whenua as well as offer mitigations to their concerns. |
February 2025 | The Environment Court accepts Rotorua Lakes Council’s undertaking to pause work on Stage 1 of the Tarawera Sewerage Scheme while it considers three applications filed in relation to the work. |
February 2025 | Works resume Stage 1 of the Tarawera Sewerage Scheme. |
January 2025 | A range of mitigation measures agreed on for Stage 1 works near Lake Rotokākahi, including double sleeving of the section of pipeline being laid 2 metres underneath the concrete culverts of the Wairoa Stream and the appointment of a pou tikanga (cultural monitor) by mana whenua to observe the final stage of the reticulation pipeline. |
December 2024 | Stage 2 – the installation of onsite LPGP systems that will connect to the network – begins. |
November 2024 | Rotorua District Court grants injunction, preventing anyone from obstructing or interfering with the installation of the pipeline along Tarawera Road or entering the work zone without authorisation from the council or its contractors. |
September 2024 | Council resolved to instruct the chief executive to complete the scheme and continue to discuss with Iwi/manawhenua leadership on how to resolve the issues raised by the RBOC and protesters. |
August-September 2024 | Discussions with Iwi leadership on how to arrive at a common position that will ensure the protection of Lake Tarawera and mitigate concerns expressed by the RBOC and members. Good faith discussions in progress. |
August 2024 | Works paused on Stage 1 following further obstruction by protesters near Lake Rotokākahi and to allow further engagement. |
July 2024 | Works resume on Stage 1. |
July 2024 | Application to the Court to issue an injunction in support of the works proceeding. Injunction application was notified to RBOC. The Court’s decision reaffirmed the Council’s statutory right to progress works in the road corridor. |
March 2024 | Large hui at Ngapuna with RBOC and beneficiaries to discuss the scheme’s background and decision making after RBOC commenced protests on the Rotokakahi site of works in January 24. |
January 2024 | Works paused on Stage 1 following obstruction by protesters near Lake Rotokākahi and to allow further engagement with iwi and mana whenua. |
September 2023 – December 2023 | Council considered the tenders for Stage 2 and after feedback from the Tarawera property and landowners in October/November. Resolved in December to enter into a contract for Stage 2. |
July 2023 -January 2024 | Communications start with the Lake Rotokākahi Board of Control (RBOC)to discuss progressing the mains pipeline on Tarawera Road and to agree cultural and risk site monitoring. |
April 2023 | Blessing held for start of Stage 1 Kaumātua and iwi representative Wairangi Jones says the karakia whakanoa blessing marks a welcome step in the collective efforts towards Te Mauri o Tarawera – protecting the health of Tarawera. “Lake Tarawera is a taonga tuku iho (ancestral taonga) for Tūhourangi and Ngāti Rangitihi, and we all have an important role as kaitiaka (guardian) of the taiao (environment) to protect and preserve it for future generations.” |
March 2023 | Stage 1 physical works begin. |
November 2022 | Council entered into a contract with Fulton Hogan for construction of Stage 1. |
August 2022 | Council resolved to adopt tenders for Stage 1 of the scheme (the mains reticulation system) to ensure that the Minister’s requirements for the $6.5m funding support can be met on the times required. |
July 2022 | Tarawera ratepayers again consulted on the 2-stage approach. Of 458 potential respondents, 349 responses were received. 313 of these supported the approach. Construction price for Stage 1 were sought through a construction contractor (with a 3rd party market pricing comparison requested to provide assurance) and prices benchmarked to the open market winning tender for the East Rotoiti scheme a year earlier. |
June 2022 | In order to meet funding deadlines imposed by (MfE $6.5m) Stage 1 construction needs to be completed by the end of December 2023. Council votes in favour of taking the 2-stage approach, allowing Stage 1 to proceed within the funding time limit imposed by MfE. More flexible repayment options were made available to Tarawera residents and were subsequently presented and adopted by Council. |
May 2022 | RLC explored option to split scheme construction into two ‘stages’: Stage 1- installing street mains and pumping systems (pricing for this was in accordance with budget). Stage 2 – connecting each dwelling to street mains (pricing for this stage was considerably higher than budget). |
December 2021 | Design begins (starting with survey work to ascertain pipeline routes and property visits to determine location of on-site treatment systems). |
November 2021 | RLC contracts for the detailed design of the preferred LPGP scheme. |
November 2021 | Tuhourangi Protocol Committee meeting held. An update on the Tarawera scheme was presented and discussion included the following: Council has approved funding through Long Term Plan to commence work this year and currently RLC is identifying a preferred contractor to design and construct the system. It is expected that construction will begin.Crown funding is currently at risk, as Minister of the Environment proposes shifting Tarawera funding to the Rotoiti/Rotoma scheme (RLC opposes this). Discussions underway to solve this issue. |
June 2021 | Council considers the results of its Long-Term Plan community consultation and adopts changes to the initial proposal for the reticulation bringing the scheme forward to 2021-2024/25 years. Council provides funds in the 2021/22 year for the detailed design of the preferred option to enable a more accurate construction cost to be defined which will determine the ‘net contribution’ to be paid by residents. Council also commits to progressing the scheme as part of the 2021-31 Long-Term Plan. |
April 2021 | Joint letter sent to all Tarawera property and landowners by Rotorua Lakes Council and the Bay of Plenty Regional Council advising status of consultation and feedback received. |
3 March 2021 | Tuhourangi Protocol Committee meeting held. An update on the Tarawera scheme was presented and discussion included the following: Viability of in-catchment Wastewater Treatment PlantNeed for cultural monitors on worksExchange of information from RRSS |
Early 2021 | Following concerns from the local community, expressed in feedback and consultations, that some in the Tarawera community may not be able to make a lump sum payment on completion, a funding sub-committee was formed. The committee consists of council officers, Rotorua Lakes Community Board, elected members, a BOPRC local member and Tarawera community representatives. The committee considers repayment options and develops criteria laying out a modified repayment option. |
February 2021 | Letters sent to all Tarawera property and landowners advising on RLC decisions in November and seeking feedback to be considered in the LTP. |
November 2020 | Council acknowledges the community request and passes resolution agreeing to incorporate funding in its draft 2021-31 Long Term Plan and the Capital Funding Plan for the phased implementation of the scheme subject to community-wide consultation of the Draft LTP |
June 2020 | Discussions with the Te Arawa Lakes Trust on the status of the project. TALT letter to RLC seeking that Council progresses the scheme with urgency. Noted the preference for in-catchment Wastewater Treatment Plant. |
March 2020 | Tuhourangi Protocol Committee meeting held. Council presented and sought; Guidance from Tūhourangi Tribal Authority and Ngāti Rangitihi on preferred response to the CIA report.Location of treatment (Rotorua or in catchment WWTP)Noted/presented the outcomes of the in-catchment WWTP feasibility reports. |
2019 | Second Cultural Impact Assessment carried out, exploring the effects of several solution options and pipeline routes. The proposed Spencer Road – Tarawera Road pipeline route was more culturally acceptable because it avoided wāhi tupuna. Council noted that Iwi appointed technical/cultural advisors should be appointed to ensure culturally sensitive sites are identified and works are designed to mitigate cultural risks. |
October 2018 | LTSSC confirms preferred option (reticulation) to the Rotorua Wastewater Treatment Plant via the public road network to Ōkāreka pumping station, with on-site low-pressure grinder pumps (LPGPs) for each property. This option was favoured because of the lowest overall long-term cost for homeowners as well as for the Council’s long-term network operations, would achieve, in the most cost-effective way the goals of removing untreated sewerage from the lake and help to measurably improve water quality at Tarawera, avoids wāhi tupuna (ancestral sites), and could be implemented quickly (resource consent is not required). |
2018 | LTSSC consider the five possible viable wastewater options. |
2017 | First Cultural Impact Assessment was undertaken. |
2015-2017 | Following BOPRC’s proposed Plan Change 14, the Lake Tarawera Sewerage Steering Committee (LTSSC) was established to consider viable options for the community to comply and potential reticulation. Committee representatives included Tūhourangi Tribal Authority, Te Mana o Ngāti Rangitihi, Māori landowners, Lake Tarawera Ratepayers Association, Te Arawa Lakes Trust, Bay of Plenty Regional Council (BOPRC) and Rotorua Lakes Council. |
