Update: Lower Waihao Nitrates

UPDATE: 18 June 2026

Nitrate levels in the water source of the Lower Waihao Rural Water Scheme (including Waikakahi East) are at 20.6mg/L of Nitrate NO3 which is under half of the Maximum Acceptable Value of 50mg/L, or 4.6mg/L of Nitrate-N with a MAV of 11.3mg/L.

UPDATE: 19 May 2026

Nitrate levels in the water source of the Lower Waihao Rural Water Scheme (including Waikakahi East) are at 28mg/L of Nitrate NO3 which is just over half of the Maximum Acceptable Value of 50mg/L, or 6.3mg/L of Nitrate-N with a MAV of 11.3mg/L.

UPDATE: 13 April 2026

Nitrate levels in the water source of the Lower Waihao Rural Water Scheme (including Waikakahi East) are at 27.6mg/L of Nitrate NO3 which is just over half of the Maximum Acceptable Value of 50mg/L, or 6.2mg/L of Nitrate-N with a MAV of 11.3mg/L.

UPDATE: 18 March 2026

Nitrate levels in the water source of the Lower Waihao Rural Water Scheme (including Waikakahi East) are at 21.2mg/L of Nitrate NO3 which is under half of the Maximum Acceptable Value of 50mg/L, or 4.78mg/L of Nitrate-N with a MAV of 11.3mg/L.

UPDATE: 20 February 2026

Nitrate levels in the water source of the Lower Waihao Rural Water Scheme (including Waikakahi East) are at 30.5mg/L of Nitrate NO3 which has a Maximum Acceptable Value (MAV) of 50mg/L, or 6.89mg/L of Nitrate-N with a MAV of 11.3mg/L.

UPDATE: 27 January 2026

Nitrate levels in the water source of the Lower Waihao Rural Water Scheme (including Waikakahi East) are at 34.3mg/L of Nitrate NO3 which has a Maximum Acceptable Value (MAV) of 50mg/L, or 7.75mg/L of Nitrate-N with a MAV of 11.3mg/L.

UPDATE: 13 January 2026

Nitrate levels in the water source of the Lower Waihao Rural Water Scheme (including Waikakahi East) are at 33.7mg/L of Nitrate NO3 which has a Maximum Acceptable Value (MAV) of 50mg/L, or 7.6mg/L of Nitrate-N with a MAV of 11.3mg/L.

UPDATE: 7 January 2026

Nitrate levels in the water source of the Lower Waihao Rural Water Scheme (including Waikakahi East) are at 36.3mg/L of Nitrate NO3 which has a Maximum Acceptable Value (MAV) of 50mg/L, or 8.2mg/L of Nitrate-N with a MAV of 11.3mg/L.

UPDATE: 12 December 2025
Nitrate levels in the water source of the Lower Waihao Rural Water Scheme (including Waikakahi East) are now at 25mg/L of Nitrate NO3 which is half the Maximum Allowable Value of 50mg/L.

As a result, the river blending process that was put in place to lower previously elevated levels will be shut down immediately,

Council's water source from the bore and treatment process is now back to normal operations.

UPDATE: 9 December 2025

The nitrate level for the Lower Waihao Rural Scheme (including Waikakahi East) was around 20mg/L Nitrate (NO3) as of 8 December 2025, pending laboratory grab sample results. This has come down significantly from the Friday 5 December level of 39mg/L due to Council initiating a river blend on Friday which mixes water pumped for the Waitaki River with the bore water. We are monitoring the nitrate levels in the bore water and will continue with the river blend until the bore water nitrate level is sufficiently reduced.

UPDATE: 5 December 2025

Elevated nitrate levels have been detected in the Lower Waihao Rural Water Scheme (including Waikakahi East). The current level is 39mg/L of Nitrate NO3 at the source of the water supply which is almost 80% of the maximum acceptable value of 50mg/L for compliance with the Drinking Water Standards.

While currently still fully compliant with the Drinking Water Standards, Council will continue monitoring nitrate levels and is undertaking a river blend as a precautionary measure. This adds water from the Waitaki River to the bore flow and will significantly reduce the nitrate level.

Nitrates have the potential to cause health issues, with an increased level of risk to both pregnant woman and infants under six months of age. The risk to a healthy adult is low but caution is advised. Unfortunately, boiling of water does not remove nitrates.

Council has made headway with a permanent solution to this issue. Recently, consent was granted for a new water source located near Bells Pond, Ikawai. Tendering began today for the installation of approximately 4.5 kilometres of new pipework to connect the new source to the existing treatment plant. A contract is in place for an upgrade of the treatment plant and modelling is also underway to establish whether Waikakahi can be connected to the same treatment plant.

Update: 20 November 2025

Nitrate levels in the Lower Waihao Rural Water Scheme (including Waikakahi East) are currently 28.1mg/L which is just over half of the Maximum Acceptable Value of 50mg/L, or 6.35mg/L of Nitrate-N against a MAV of 11.3mg/L.

Update: 12 November 2025

Nitrate levels in the Lower Waihao Rural Water Scheme (including Waikakahi East) are currently 25.5mg/L which is just over half of the Maximum Acceptable Value of 50mg/L, or 5.75mg/L of Nitrate-N against a MAV of 11.3mg/L.

UPDATE: 3 November 2025

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Nitrate levels in the Lower Waihao Rural Water Scheme (including Waikakahi East) are currently 22.5mg/L which is just under half of the Maximum Acceptable Value of 50mg/L, or 5.09mg/L of Nitrate-N against a MAV of 11.3mg/L.

UPDATE: 29 August 2025

Nitrate levels in the Lower Waihao Rural Water Scheme (including Waikakahi East) are currently 24mg/L (Nitrate-N = 5.5)which is just under half of the Maximum Acceptable Value of 50mg/L (Nitrate-N = 11.3).

Working toward securing a long-term solution to elevated nitrate levels, a resource consent application has been lodged with Environment Canterbury for a new water source located near Bells Pond, Ikawai. The associated media release can be read HERE

UPDATE: 9 April 2025

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Nitrate levels in the Lower Waihao Rural Water Scheme (including Waikakahi East) are currently 24.1mg/L which is just under half of the Maximum Acceptable Value of 50mg/L.

As the scheme water now meets the Drinking Water Standards the temporary alternative supply tanks located at the Glenavy and Morven Halls will no longer be provided with alternative source water.

The tank located at the rear of the Glenavy Hall is now supplied with water from the Lower Waihao Water Scheme and is available to those that do not have a Lower Waihao Rural Water Scheme Connection. The alternative supply tank at the Morven Hall is now empty and will remain empty. These alternative supply sources can however be reinstated if required.

Council is continuing plans for an alternative acceptable water source which isn’t detrimentally affected by fluctuating nitrate levels.

UPDATE: 18 December 2024

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Nitrates levels in the Lower Waihao Rural Water Scheme (including Waikakahi East) have reduced and the water can now be consumed again.

Nitrate levels on the Lower Waihao Rural Water Scheme exceeded the Maximum Acceptable Value of 50mg/L on 2 December 2024 and a Cease Consumption notice was put in place.

Using an alternative supply from the Waitaki River, Waimate District Council staff have now been able to reduce the nitrate concentration in the Lower Waihao water supply to approximately 26mg/L and are advising consumers that they can use the water for drinking and cooking again.

Nitrate samples have been taken from a number of different locations throughout the distribution network and all samples have shown a reduction in nitrates levels to well within the acceptable limit.

If households have had limited turnover in their water storage tanks since Tuesday 10 December, Council would advise consumers to release around a quarter of their tank storage to ensure fresh water is circulating through the tank. Council would encourage mindful water use if possible such as using the discharged water to give gardens a good watering or washing vehicles. Many tanks will have already had this turnover through continued use for daily household activities (showering, washing etc) or stockwater use.

The temporary take set up from the Waitaki River is likely to be in place for a number of months while plans are finalised for a more permanent solution for a water take in a different location.

The existing alternative water supply tanks at the Glenavy and Morven Halls will remain in place for the next few months – ensuring all residents continue to have access to safe drinking water in the event of another surge or spike in nitrates.

All consumers are encouraged to sign up to NotifyMe, Council’s public notification system to stay informed about the water supply.

To sign up go to waimatedc.govt.nz/notifyme

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UPDATE: 2 December

Nitrates levels within Lower Waihao Rural Water Supply (inc. Waikakahi East) have breached the maximum accepted value (MAV) for nitrates. All consumers on the respective water supplies should cease the use of the water for direct consumption and cooking.

Water for drinking and cooking is available to all Lower Waihao Rural Water Supply (inc. Waikakahi East) users at the following supply points:

• Glenavy Hall, SH 1, Glenavy (Tank with tap)

• Morven Hall, MacLean Street, Morven (Tank with tap)

• 26 Studholme Street, Waimate (Tap located on street boundary)

Council is continuously monitoring the nitrates level and will advise consumers when it is safe to reuse the water supplies.

All residents are encouraged to sign up to NotifyMe, Council’s public notification system to get regular updates about the water supplies. To sign up go to waimatedc.govt.nz/notifyme

Information regarding nitrate levels can also be found HERE.

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UPDATE: 29 November

Elevated nitrate levels of 49mg/L of Nitrate NO3 (29 November 2024) have been detected at the source of the water supply and may rise further. The maximum acceptable value is 50mg/L for compliance with the Drinking Water Standards. Nitrates have the potential to cause health issues, with an increased level of risk to both pregnant woman and infants under six months of age. The risk to a healthy adult is low but caution is advised.

Please note, the usual method of boiling of water does not remove nitrates.

To ensure safe drinking water is available to all Lower Waihao Water Scheme users, water from alternative sources is available at the following locations for the community to access:

• Glenavy Hall, SH 1, Glenavy
• Morven Hall, MacLean Street, Morven
• Studholme Street, Waimate (Potable Water tap)

Whilst currently still fully compliant with the Drinking Water Standards the alternate supply points can be accessed by all consumers on the Lower Waihao and Waikakahi East water supplies. Council is continuously monitoring nitrates within the supply and are working through complex options for a solution to this issue.

Further information regarding nitrates in drinking water, and the current nitrate levels in the water scheme can be found here.

Dan Mitchell

Asset Group Manager

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UPDATE: 25 November

Elevated nitrate levels of 47mg/L of Nitrate NO3 (25 November 2024) have been detected at the source of the water supply and may rise further. The maximum acceptable value is 50mg/L for compliance with the Drinking Water Standards. Nitrates have the potential to cause health issues, with an increased level of risk to both pregnant woman and infants under six months of age. The risk to a healthy adult is low but caution is advised.

Please note, the usual method of boiling of water does not remove nitrates.

To ensure safe drinking water is available to all Lower Waihao Water Scheme users, water from alternative sources is available at the following locations for the community to access:

• Glenavy Hall, SH 1, Glenavy
• Morven Hall, MacLean Street, Morven
• Studholme Street, Waimate (Potable Water tap)

Whilst currently still fully compliant with the Drinking Water Standards the alternate supply points can be accessed by all consumers on the Lower Waihao and Waikakahi East water supplies. Council is continuously monitoring nitrates within the supply and are working through complex options for a solution to this issue.

Further information regarding nitrates in drinking water, and the current nitrate levels in the water scheme can be found here.

Dan Mitchell

Asset Group Manager

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UPDATE: 18 November

Monitoring of the nitrates in the Lower Waihao Rural Water Scheme (including Waikakahi East) has shown that the nitrate level is currently 45mg/l.

It is important to reassure the community that the water remains safe to drink and is compliant with the Drinking Water Standards for New Zealand.

Council continues to undertake regular sampling at the water source, with these samples independently tested by an accredited laboratory. Council also has an online nitrate probe to monitor the nitrate levels in real-time, so simply put, we are keeping very close tabs on the situation.

Council would like to remind consumers that alternative supply water tanks can be found at:

• Glenavy Hall, SH1, Glenavy

• Morven Hall, MacLean Street, Morven

• Glenavy Fishing Camp

• Glenavy School

Please note, boiling water does not remove nitrates.

Stuart Duncan

Chief Executive