Hāhei Water Extension

Currently, the lots within the project's area of service receive water from the Hāhei Water Supply Association bores via a local network. The existing water network was not designed for peak flows or firefighting capability, and no fire hydrants are installed on the network.

The scheduled extension would include the following:

1. A new water supply network with water mains that supplies properties in Grierson Close, Beach Road, Harsant Avenue, Dawn Avenue, John Spear Avenue, Robyn Crescent, and Tutaritari Road.
2. Each residential lot (SUIP unit) will have a service connection with a backflow prevention device and meter box with provision to install a water meter at a later stage.
3. The water network will be supplied from the existing reservoir tanks at the end of Grierson Close.

The Council will supply the following aspects of the system:

• Water reticulation mains, including isolation valves and fire hydrants.
• Service connection at the boundary for each property (each SUIP unit separately) consisting of a pipe manifold with backflow prevention device inside a meter box, with provision to install a water meter.

Each property owner, at their own cost, will need to:

• Install pipes to connect their existing on-property plumbing to the newly installed Council service connection at their boundary.

The higher elevation properties in Tutaritari Road would have low water pressure if they were only supplied by a gravity feed from the reservoir. A booster pump station (BPS) is required to increase the pressure in the water main to have sufficient water pressure at each lot in this area. It would also be required to boost the water pressure during firefighting events to provide a reliable water supply to fight fires.

A suitable location for the BPS has been identified at the open grassed area along Grange Road, close to no. 1 Tutaritari Road. The proposed location is shown in Figure 2 below.

The proposed installation would include the following:

• Steel/aluminium shed on top of a concrete slab to house pipes and pumping equipment.
• Electric booster pump set and pipework.
• Electrical works to provide power and to control the pump operation.

Key design assumptions used to develop the design are as follows:

• The size of the water network has been developed to handle peak flows, during peak occupancy periods and meet firefighting requirements. The water network was also sized to handle possible future growth scenarios such as increased occupancy levels, and potential subdividing or infilling of lots.
• Peak flows assumed a peak period occupancy of approximately five people per lot.
• Hāhei Beach Road, Harsant Avenue, Dawn Avenue, and Robyn Crescent would have a larger water main on one side of the road for the installation of fire hydrants and service connections, and a smaller water main on the opposite side of the road with service connections only.
• Tutaritari Road is very narrow and would only have one larger water main ending with a fire hydrant at the top of the road. The fire hydrant would serve as both a connection point for firefighting and a scour point for periodic flushing of the water main.
• The water mains will be installed by trenchless techniques such as horizontal directional drilling (HDD). This would have less disturbance caused by trench excavations and less surface (road/grass/walkway/driveway) reinstatement. Where HDD is not practical, conventional trench excavation would be done.
• The existing association water pipelines will be decommissioned (capped) and left in the ground. 

The estimated total capital cost for the water extension is $2,902,800+GST (inflation adjusted).

This would equate to a per SUIP unit cost of $20,814.18+GST including development contributions. The calculation is presented in the table below.

Note, the final cost per property (each SUIP unit) can only be determined after conclusion of detailed design, tendering and construction of these works and all project costs are confirmed.

What would you likely pay

1.1 Capital Cost

The estimated capital cost of $16,493.18 for each property (each SUIP unit) can be paid after completion of the project as:

a) A one-off payment, or
b) A targeted rate over a maximum period of 10 years, which will also include interest and administration charges.
c) Alternatively, payment could be made by a partial upfront payment and payment of the balance (including interest and administration charges) through targeted rates.

These amounts will be payable on a per SUIP basis, meaning each Separately Used or Inhabited Part of a rating unit includes any part inhabited or used by a person other than the owner, and who has the right to inhabit or use that part by virtue of a tenancy lease, license, or other agreement (such as a separate dwelling, flat, or unit on a property that receives its own water/wastewater connection) will be charged individually.

This means that if your property contains multiple SUIPs as described above, it will be charged based on the number of those units, as each receives its own water connection.

1.2          Development Contribution charges

Payment of the estimated development contribution charges ($4321) will only be required when the property (each SUIP unit) is connected to the water network, after the capital project is completed. If you do not connect when the new network is available, then then the development contribution charge (as set at that date) would only be applicable if and when you connect in the future.

Development contribution charges are considered as a share of the cost of existing or planned network-wide infrastructure, like treatment plants, bulk mains, reservoirs, etc. in addition to the direct capital cost of the project. This ensures that growth-related costs are fairly distributed among those who create the demand, rather than by existing ratepayers for the water service.

1.3          Water Rates

a) If you connect to the network then, from the time of connection, each property (each SUIP unit) will include the water serviced rates, with annual rates proposed at $1,155.46 per annum. This is the current applicable water serviced rates but is subject to change as Council reassesses and sets it proposed rates each year.

b) If you decide not to connect then your property (SUIP unit) will be charged the water serviceable rates at $866.60 per annum once the project is completed.  This is the current applicable water serviceable rates but is subject to change as Council reassesses and sets it proposed rates each year. 

Your property:

i) Will still be liable for targeted rates covering the capital cost of the project
ii) But will not be charged for the Development Contributions.  Note: if you decide to connect at a later date, you will be required to pay the development contribution charges applicable at that time that you connect.

Please refer to the FAQ sheet on this webpage for answers to other common questions you may have regarding this.