Services and activities
The sewerage and sewage group includes activities and services related to waste water. Wastewater is the dirty water discharged from toilets, kitchens, bathrooms and laundries in dwellings and commercial premises. It also includes trade waste discharged from industrial premises into public sewers. The DCC collects domestic and trade wastewater via its systems of sewers and pumping stations, and transfers them to the wastewater treatment plants, where it is treated to a standard acceptable for discharge to the environment.
The DCC protects public health and safety by delivering effective wastewater services to every customer connected to the network with a minimal impact on the environment and at an acceptable financial cost.
Community outcomes
The sewerage and sewage group contribute s to the following community outcomes:
- A sustainable city with healthy and treasured natural environments
- A healthy city with reliable and quality water, wastewater and stormwater systems
- A supportive city with caring communities and a great quality of life
Significant Negative effects
The collection treatment and discharge of treated wastewater may have potential negative effects on the interests of the community. The 3 Waters Strategic Direction Statement and the system planning approach prioritises and plans the resolution of these issues and recognises that some issues can only be resolved pragmatically over longer periods of time.
- Locations of treatment plants close to residential properties can give rise to issues with odour or noise.
Potential negative effects are managed as part of day-to-day operation of the treatment plants (including responding to customer complaints). Community liaison has been initiated in known areas of community concern, and complex odour and noise mitigation is programmed at treatment plants.
- High trade waste charges may affect industries expanding/relocating to Dunedin or treatment upgrade costs contributing to rating increases that are unviable for those ratepayers on low incomes. Implementation of Strategic Direction Statement should minimise operational cost increases.
System planning looks at long term strategic investment objectives and outcomes for the optimal cost/benefit ratio.
- Discharge from the wastewater system from treatment plants and overflows from the network can impact the local community. These discharges to the environment can be planned (e.g. the constant discharge of treated wastewater via an ocean outfall) or unplanned (e.g. a heavy rainfall event, blockage or broken pipe in the network causing an overflow). There is also the potential for wastewater to enter the stormwater (e.g. in heavy rainfall events).
Potential negative effects are managed as part of the day-to-day operation of the wastewater activity. Activities are permitted and regulated by conditions of relevant resources, which ensure potential adverse effects are managed at acceptable levels. This includes monitoring of the effluent and sediment/coastal receiving waters and impact assessments. Renewal programmes for the treatment plants and wastewater network are intended to minimise the incidence of asset failures. System planning looks at long term strategic investment objectives and outcomes for the network, treatment plants and sludge treatment and disposal. Mana whenua are engaged as partners in system planning.
Measuring performance
| Measure | Data Source | Actual Year 2 2022/23 | Target 2024/25 | |
|---|---|---|---|---|
| Level of service: Sewage is managed without adversely affecting the quality of the receiving environment | ||||
| The number of dry weather sewerage overflows from the sewerage system, expressed per 1000 sewerage connections to that sewerage system. (DIA measure) | Internal data | 3.58 overflows per 1,000 connections | 0 | |
| Compliance with DCC resource consents for discharge from its sewerage system measured by the number of abatement notices, infringement notices, enforcement orders and convictions. (DIA measure). | Internal data | 1 | 0 | |
| Level of service: Service calls are responded to promptly | ||||
| Where the DCC attends to sewerage overflows resulting from a blockage or other fault in sewerage system, the following median response times are measured: (DIA measure) | a) Attendance time from the time notification is received to the time that service personnel reach the site; and | Internal data | 36 minutes | <60 minutes |
| b) Resolution time: from the time notification is received to the time that service personnel confirm resolution of the blockage or other fault. | 125 minutes | < 240 minutes | ||
| Level of service: The wastewater service is reliable, and the Council is responsive to customer concerns | ||||
| Percentage of residents satisfied with the sewerage system | ROS | 68% | >65 | |
| The total number of complaints received about any of the following: (DIA measure) | Sewage odour | Internal data | 5 | Not applicable |
| Sewerage system faults | 86 | Not applicable | ||
| Sewerage system blockages | 158 | Not applicable | ||
| Response to issues with the sewage system expressed per 1,000 connections to the sewerage system. | 0.02 per 1,000 connections | Not applicable | ||
| All of the above complaints expressed per 1000 connections to the territorial authority’s sewerage system. | 5.8 per 1,000 con`nections | <5 per 1,000 connections each year | ||
ROS - Residents’ Opinion Survey
| Dunedin City Council Funding Impact Statement for the Year Ended 30 June 2025 for Wastewater | |||
|---|---|---|---|
| (shown in $000)s | 2023/24 Annual Plan | 2024/25 Long-term plan | 2024/25 Annual Plan |
| Sources of operating funding | |||
| General rates, uniform annual general charges, rates penalties | 0 | 0 | 0 |
| Targeted rates | 35,996 | 34,015 | 41,392 |
| Subsidies and grants for operating purposes | 1,961 | 43 | 41 |
| Fees and charges | 932 | 934 | 896 |
| Internal charges and overheads recovered | 0 | 0 | 221 |
| Interest and dividends from investments | 0 | 0 | 0 |
| Local authorities fuel tax, fines, infringement fees, and other receipts | 0 | 0 | 0 |
| Total operating funding (A) | 38,889 | 34,992 | 42,550 |
| Applications of operating funding | |||
| Payments to staff and suppliers | 18,481 | 16,188 | 18,528 |
| Finance costs | 4,575 | 1,441 | 4,493 |
| Internal charges and overheads applied | 2,874 | 3,146 | 2,603 |
| Other operating funding applications | 0 | 0 | 0 |
| Total application of operating funding (B) | 25,930 | 20,775 | 25,624 |
| Surplus/(deficit) of operating funding (A-B) | 12,959 | 14,217 | 16,926 |
| Sources of capital funding | |||
| Subsidies and grants for capital expenditure | 0 | 0 | 84 |
| Development and financial contributions | 1,090 | 1,114 | 1,090 |
| Increase/(decrease) in debt | 23,820 | 3,078 | 10,323 |
| Gross proceeds from sale of assets | 0 | 0 | 0 |
| Lump sum contributions | 0 | 0 | 0 |
| Other dedicated capital funding | 0 | 0 | 0 |
| Total sources of capital funding (C) | 24,910 | 4,192 | 11,497 |
| Application of capital funding | |||
| Capital expenditure | |||
| - to meet additional demand | 1,641 | 2,301 | 2,240 |
| - to improve the level of service | 2,617 | 511 | 12,754 |
| - to replace existing assets | 33,611 | 14,353 | 13,429 |
| Increase/(decrease) in reserves | 0 | 0 | 0 |
| Increase/(decrease) of investments | 0 | 1,244 | 0 |
| Total application of capital funding (D) | 37,869 | 18,409 | 28,423 |
| Surplus/(deficit) of capital funding (C-D) | -12,959 | -14,217 | -16,926 |
| Funding balance ((A-B)+(C-D)) | 0 | 0 | 0 |