Drinking Water Projects

We have planned to drill two new bores over the next 10 years, one in Ashburton, the other Rakaia. The Rakaia bore is to provide redundancy for the single existing bore. Should the bore, pump or headworks experience problems, it is very difficult and expensive to provide alternative supply. This is a significant risk to the water supply. Therefore, we have budgeted $462,000 across Year 1 and 2 of our 2021-31 Long-Term Plan to design and construct an additional bore. The bore in Ashburton, however, is a placeholder in Year 6 to provide additional capacity at either Argyle Park or Bridge Street. For example, if there is a large amount of development around the Argyle Park area and the existing bores are unable to maintain supply at peak times, an additional bore will be required. However, if the water meter project is able to reduce water loss significantly, this project may not be required and will be deferred until later years. We have budgeted $686,000 across Years 5 and 6 for this.

As part of the development of our Long-Term Plan 2021-31, we asked our community whether they wanted us to install universal water meters to identify leaks. After consideration of the feedback we received, we decided to take a measured approach to installation.

Water meters will be installed in 2021/22 in the Methven township. Analysis of water loss data will be undertaken in 2022/23 to identify whether there is a significant amount of water lost from the system – as per our estimates, and what proportion of leaks are on private versus public property. We will then consult with the community through the 2024-34 Long-Term Plan to install water meters in Ashburton and Rakaia if the Methven trial shows it would be worthwhile.

We have provision in our long-term budget for membrane treatment plants on the Methven, Methven-Springfield, Mount Somers and Montalto water schemes. This is needed to achieve protozoa treatment compliance with the drinking water standards.

We have included $4.59 million (Methven), $3.76 million (Methven-Springfield), $2.91 million (Mt Somers), and $4.12 million (Montalto) in our Long-Term Plan 2021-31 for these upgrades – design in 2021/22 and construction in 2022/23 and 2023/24. However, we intend to investigate the option of one treatment plant covering all schemes, as this would significantly reduce the cost if it is feasible.

You can read about this project here.

Methven currently has 700m³ of available water storage in an old concrete reservoir. This reservoir has been assessed and is not seismically sound, and is therefore at risk of failure in an earthquake. We built a 500m³ reservoir in 2020/21, and in July 2021 Council approved up to $9.4 million to improve Methven’s drinking water – an upgrade that will commission detailed plans for a new membrane treatment plant, and build two new reservoirs to help meet peak demand on the scheme.

The new plant will be able to treat the water and filter it potentially at a molecular level. The water would then be held in the two new reservoirs, with a combined capacity of 1,128m³, for distribution to Methven residents.

The new tanks are made of special glass-fused steel and will be imported from the UK. The construction and installation project for the new reservoirs is expected to take nine months.

We will continue our programme of watermain renewals across the district in line with depreciation.

We will install UV disinfection on all our deep groundwater supplies (Ashburton, Chertsey, Dromore, Fairton, Hinds, Mayfield and Rakaia). This provides a second barrier to bacterial and protozoal contamination of the source water and will assist us in continuing to have ‘secure’ groundwater status under the Drinking Water Standards NZ. The following has been budgeted in our Long-Term Plan 2021-31 for design and construction of the upgrades:

• Dromore: $46,300 in 2022/23
• Fairton: $51,500 in 2022/23
• Ashburton: $3.2 million - design in 2022/23, construction in 2023/24 and 2024/25
• Hinds: $211,360 in 2023/24
• Rakaia: $324,000 – design in 2023/24, construction in 2024/25
• Chertsey: $48,790 in 2024/25
• Mayfield: $48,790 in 2024/25