Where our water comes from

Akaroa and Takamātua are supplied from a reticulated water network using local water sources and treatment.

Water for the Akaroa water supply scheme is taken from four streams; Aylmers, Grehan, Balguerie and Takamātua, and two wells, one at Settlers Hill Road (41 metres deep) and one at Aylmers Valley (138 metres deep).

Water is piped from these sources to the L'Aube Hill water treatment plant located above the L’Aube Hill Reserve. The raw water is stored in a reservoir that was originally constructed in the early 1900s to provide water for the Akaroa hydro-power generator that first provided electricity to the community.  The power station was located on Rue Pompallier and is preserved by the Akaroa Hydro Generating Set Trust.

The water is then treated using membrane filtration and chlorination. Membrane backflushes, washdown and service water is discharged to the Akaroa wastewater network.

The treated water is primarily stored at the L’Aube Hill site to gravity feed most of Akaroa. Water is also stored at two other main treated water reservoirs supplied from L’Aube Hill. One at the top of Old Coach Road which supplies Takamātua and the other at a former water treatment plant site on Aylmers Valley Road.  There are also four smaller reservoir sites in the network which are fed by small pump stations. These supply small areas that are too high to gravity feed from the L’Aube Hill, Aylmers Valley or Old Coach Road reservoirs. 

An upgrade project is currently underway to install new monitoring equipment to make the plant compliant with the Drinking Water Quality Assurance Rules introduced in 2022. Two new reservoirs (1,000,000 litre capacity each) to store treated water are also being constructed.

Water for the Birdlings Flat water supply is sourced from a well located on Jones Road and is pumped to the Bridlings Flat water treatment plant, which is located between Baileys Road and Poranui Beach Road.

Water from the well is stored in above-ground tanks at the treatment plant. It is then filtered to remove any sediment from the bore, disinfected with UV light and finally dosed with chlorine to provide distribution disinfection.

The treated water is then pumped into the reticulation network.

The Birdlings Flat water supply is a restricted water supply. Each property is required to have a private storage tank and can receive up to 1,000 litres of water per day.

An upgrade project is currently underway to install new monitoring equipment to make the plant compliant with the Drinking Water Quality Assurance Rules introduced in 2022. Whilst this work is underway other works at the site will be undertaken to provide additional resilience to the supply and carry out planned equipment replacements.

The Council has consent from the regional council, Environment Canterbury, to take water from wells within the city, sunk down into the aquifers. There are 53 locations around the city where water is pumped into the pipe network. At each of these extraction sites, there is at least one, and sometimes up to six, wells. These wells are typically 200mm and 300mm in diameter and are drilled down to depths ranging from 22 to 220 metres.

There are five layers of confined aquifers, with about 25 per cent of Christchurch’s water supply being sourced from the shallowest aquifer.  A programme is underway in the northwest of the city to replace some shallow wells with deeper wells, and once this is complete only 15 per cent of the city's water will come from the shallowest aquifer.  The water in these confined aquifers is under pressure, giving rise to artesian wells that in some locations flow freely at the surface.  

In Christchurch, water is delivered into water mains by electrically driven pumps keeping the mains pressurised and charged. The pressure forces water out when you turn on a tap in your house.

Where reservoirs or large tanks are sited on hill areas, water pressure is maintained by continually supplying water to the level of the reservoir. In areas where there are no nearby hills to put tanks on, pumps are kept running to ensure continuous water pressure 24 hours a day.

Although Christchurch appears flat, there is actually a significant difference in land elevation from the east to the west of the city. Up to five pressure zones are needed, depending on the height of the residential development. In addition, there is also a small public water supply at Brooklands and Kainga.

The water supply network is controlled from a central control room. As the pressure in the system falls and rises around the district, pumps are switched on and off by a combination of automatic and manual controls.

Pipe network

A vast network of pipes covers all urban parts of the city. This underground infrastructure spans from Belfast in the north to the hill suburbs in the south, and from Templeton in the west to Taylors Mistake in the east.  More than 1,700 kilometres of main pipes are laid - enough pipes to run from Christchurch to Whangarei. The total length of underground pipework, including submains, is 3,300 kilometres.

This network of pipes ensures that when a section of pipe has to be isolated for replacement or repairs, the number of households affected by stopped water supply is minimal. The main distribution pipes are made from fibrolite, PVC, polyethylene and cast iron. The pipes distribute all of the water and provide water for Council-maintained fire hydrants on the main pipes.

Water for the Duvauchelle water supply is sourced from Pipers Stream. Surface water abstracted from the stream is piped by gravity to the treatment plant located on Okains Bay Road. 

At the treatment plant, the stream water passes through a series of filters before being disinfected with UV light and dosed with chlorine. Treated water then passes into the treated water reservoir at the treatment plant site.

Treated water then flows by gravity into the township or is pumped up to the Ngaio Point subdivision.

Because the current treatment plant is unable to effectively treat raw water with high levels of turbidity and soluble organics issues arise during periods of high rainfall when these contaminants are mobilised. When this occurs, the plant is unable to operate adequately and water is tankered in from another Council supply. Normally from Akaroa.

An upgrade project is currently underway to replace the existing treatment equipment with a membrane filtration plant. This new plant will be able to treat water with high turbidity and levels of organics. It is expected that this plant will be commissioned by the end of 2028.

Water for the Little River water supply comes from two sources; a stream intake above Little River on Police Creek and a bore near the lower end of Council Hill Road.

The site normally operates on stream water which is piped from the Police Creek intake and passed through a pair of slow sand filtration tanks before being UV disinfected and chlorine treated.

Treated water is then stored at the treatment plant reservoir before being reticulated into Litle River.

During periods of heavy rain, the turbidity of the surface water abstracted from Police Creek can rise above the level that the sand filters can treat. At these times, groundwater is sourced from a 115-meter-deep well located at the bottom of Council Hill Road. This water is then pumped up to the treatment plant where it is treated by UV disinfection before being dosed by chlorine and passing into the treated water storage reservoir.

The bore is sometimes used in very dry periods when the flows in Police Creek are very low.

Water is reticulated throughout Little River as well as branches that extend into Cooptown.

The Little River water supply is a restricted water supply. Each property is required to have a private storage tank and can receive up to 1,000 litres of water per day.

An upgrade project is currently underway to install new monitoring equipment to make the plant compliant with the Drinking Water Quality Assurance Rules introduced in 2022. Whilst this work is underway other works at the site will be undertaken to provide additional resilience to the supply and carry out planned equipment replacements.

Water for the Pigeon Bay supply is sourced from a spring above Dick Stream and passes through four settlement tanks to remove sediment before flowing by gravity to the treatment plant on Pigeon Bay Road.

At the treatment plant, the raw water passes through a filter before being disinfected with UV light and dosed with chlorine. It then enters the reticulation network.

Treated water is stored in three small reservoirs spread through Pigeon Bay.

The Pigeon Bay water supply is a restricted water supply. Each property is required to have a private storage tank and can receive up to 1,000 litres of water per day.

An upgrade project is currently underway to install new monitoring equipment to make the plant compliant with the Drinking Water Quality Assurance Rules introduced in 2022. Whilst this work is underway other works at the site will be undertaken to provide additional resilience to the supply and carry out planned equipment replacements.

Water for the Wainui water supply is sourced from a 92-metre-deep well located on Wainui Valley Road. Water pumped from the well is chlorinated before entering the reticulation network.

Treated water is stored at two treated water reservoir sites, one at the top of Wainui Valley Road and the other near the top of Warnerville Road.

The Wainui water supply is a restricted water supply. Each property is required to have a private storage tank and can receive up to 1,000 litres of water per day.

An upgrade project is currently underway to install new monitoring equipment to make the plant compliant with the Drinking Water Quality Assurance Rules introduced in 2022. Whilst this work is underway other upgrades to the site will be undertaken, including the installation of a generator at the treatment plant to provide additional resilience to the supply in the event of a power outage.