Darfield and Kirwee Wastewater Pipeline Project
Darfield and Kirwee are two of the largest communities in New Zealand without a reticulated wastewater (sewerage) system. Currently, residents and businesses in Darfield and Kirwee manage their own wastewater, relying on septic tanks and on-site treatment plants.
The existing approach to wastewater discharges (on-site and to ground) has been identified as a potential risk to public health in the long-term and a limitation to growth of these communities.
To reduce any potential risk to human health or the environment, and to better provide for the ongoing population growth that both Darfield and Kirwee are experiencing, the Council is constructing a new wastewater system to service these townships.
This wastewater system will collect the sewerage from both Darfield and Kirwee townships, and pipe it to the existing Pines Wastewater Treatment Plant (WWTP) in Rolleston for treatment.
The project is part of the Council’s Long-Term Plan 2021-2031 and the Council successfully applied for $10.66 million of government funding for this project as part of the post COVID-19 Water Stimulus Package.
Where is the pipeline going to be built?
The pipeline is 26.5km long and begins south of Darfield and ends at the Pines Wastewater Treatment Plant (WWTP) on Burnham School Road, Rolleston. A pipeline from Kirwee will also be constructed, connecting to the main trunk at the junction of Courtenay Road/Miles Road. The pipeline will be located within the road reserve (between the road and private property boundaries). The route is shown on the online project map below which shows the progress made.
How long will construction take?
The construction of the main pipeline to the Pines wastewater treatment plant is planned to begin in August 2021 and be completed by July 2022 for Darfield and August 2022 for Kirwee. To see the latest progress on the construction of the pipeline, check the map above.
Will my property be affected by the construction?
As most of this work is taking place in the road reserve, traffic management and speed reductions are likely to be necessary for short periods of time during construction. Brief road closures will be required and we will be in touch with property owners affected by these as soon as this is confirmed. Check our local roads disruptions and closures map for the latest closures and detours.
The Council and its contractors will maintain access to your property throughout these works but please contact us if you have any specific concerns.
There will be no disruption to existing underground services, such as water, wastewater and storm water during the construction of the pipeline.
What’s the plan for properties connecting to the new pipeline?
The new pipeline will service both Darfield and Kirwee townships. Properties will connect to the pipeline in the following stages:
Stage 1 (starting August 2021): Complete the pipeline to the Pines wastewater treatment plant and require all new developments in Darfield and Kirwee to connect. Construct the sewer pipeline along the main street in Darfield in 2022/23, with businesses connecting from 2023/24.
Stage 2 (2021–2023): Together with Environment Canterbury, gather information on the current status of consented septic tanks. This will help inform the timing of the connection rollout. The Council will also review how the scheme should be funded.
Stage 3 (2025–2030): Construction of the local pipework to allow connections in higher risk areas of Darfield and Kirwee townships, such as areas with unconsented septic tanks.
Stage 4 (2031–2035): Construction of the local pipework to allow connections in lower risk areas of Darfield and Kirwee townships, such as areas with more recent consents for septic tanks.
History of the project
In the 2017/18 Annual Plan the Council signalled that a joint working party involving representatives from the Council, the Malvern Community Board, the Darfield and Kirwee Township Committees, Canterbury District Health Board and Environment Canterbury would further consider options for the possible establishment of a wastewater scheme for Darfield and Kirwee, which do not currently have a reticulated wastewater system.
The Council undertook a business case for the scheme, including consultation with Darfield and Kirwee residents in 2019.
Following this, the Council voted in February 2020 to progress work on a wastewater scheme for Darfield and Kirwee.
The Council agreed that there was sufficient evidence to support planning for a wastewater scheme in central Darfield. Further consultation on a possible system for central Darfield and developments in the township was part of the consultation for the 2020/21 Annual Plan. The Council confirmed it would continue to seek cost-effective and environmentally sound solutions for both the Darfield and Kirwee communities.
In December 2020 the Council was granted $10.66 million of funding from the Department of Internal Affairs for the project as part of the three waters infrastructure stimulus funding post-COVID-19.
In the Long-Term Plan 2021-2031 the Council included further consultation on the proposal for the wastewater scheme. In response to feedback from the public it agreed to continue with the proposal, constructing the scheme for all new developments and for the central business area in Darfield, and to review the costs and timeline for existing homes to connect to the to the scheme.
The following documents have been previously commissioned and are available for download.
- Preliminary Report on the Issues and Options for Land Treatment and Disposal of Sewage from Darfield 1996
- Modelling impact of Darfield and Kirwee Wastewater Discharges on Groundwater Quality 2011
- Existing onsite wastewater treatment systems assessment in Darfield 2014
- The Potential Hazard On-Site wastewater Treatment Systems in Darfield and Kirwee 2014 (and Appendices)
- Public health risk assessment of sewage disposal by onsite wastewater treatment and disposal systems in the Darfield and Kirwee Communities 2014
- Darfield Wastewater Strategy 2016
- Darfield and Kirwee Wastewater Strategy 2017
- Darfield Public Meeting Presentation 2019
- Darfield Wastewater Case for Change
- 2021 Groundwater Monitoring