If you hold an ECan resource consent for a water take, verifying your flow meter isn't optional, it's a consent condition. Here's a clear breakdown of verification intervals, by meter type, in line with current ECan requirements.
The legal basis for flow meter verification sits in the Resource Management (Measurement and Reporting of Water Takes) Regulations 2010. These regulations require all consent holders taking ground or surface water above certain thresholds to accurately measure, record, and report their water takes.
In Canterbury, ECan enforces this through individual resource consent conditions. Your consent will specify that your flow meter must operate within a tolerance of ±5% accuracy when compared against a calibrated verification meter. If your meter has drifted outside that tolerance, which happens gradually over time, particularly with mechanical meters, your recorded water take data may be inaccurate, and you may be in breach of your consent without realising it.
The consequences of non-compliance aren't trivial. Inaccurate records are difficult to retrospectively correct, and if ECan audits your consent and finds your meter hasn't been verified within the required timeframe, you may face enforcement action. Staying on top of your verification schedule is one of the simplest ways to protect your consent.
Electromagnetic flow meters must be verified every five years. Mag meters are the most common flow meter type for Canterbury irrigation applications. They have no moving parts, which means they're reliable and low maintenance over their working life. They do, however, drift over time, electrode fouling, transmitter drift, and changes in the installation environment can all affect accuracy.
If you have a mag meter and you're not sure when it was last verified, contact us and we'll check your records or carry out a verification to establish your current accuracy.
Ultrasonic flow meters must also be verified every five years. Ultrasonic meters are increasingly specified for larger diameter irrigation mains. The five-yearly verification interval applies to both clamp-on and inline ultrasonic configurations.
Mechanical and turbine flow meters must also be verified every five years, the same interval as mag and ultrasonic meters. Mechanical meters have moving parts, impellers, bearings, and seals, that wear over time, so regular verification remains important to confirm ongoing accuracy.
If you have a mechanical meter that's getting on in years, it's worth considering an upgrade to a mag meter: the longer verification interval alone can offset a significant portion of the replacement cost over time.
If you've recently had a new flow meter installed or replaced an existing one, it must be verified and the documentation supplied to ECan within six months of installation. NZ Flow Group carries out this initial verification as part of every installation we complete.
It depends on your consent conditions. There is a common understanding that mag flow meters require re-verification every 5 years, ultrasonic (clamp-on type) meters every 3 years, and mechanical meters every 2 years. In practice, our experience has shown that for now, all meter types fall under a 5-yearly rotation, though this may change in the future. New meters are verified within six months of installation, and trade waste discharge meters are typically required to be verified annually. Contact us if you're unsure what applies to your specific situation.
ECan specifies that an Ultrasonic Clamp-On type flow meter must be used to carry out flow meter verifications in the Canterbury region. NZ Flow Group uses the Flexim Fluxus F601 portable ultrasonic meter. Our units are sent away for IANZ-accredited calibration every year, compared against a certified flow rig under fixed conditions.
A typical site visit takes between one and two hours. We handle the compliance documentation and can supply it directly to ECan on your behalf.
Your meter may be out of spec without you knowing. A meter that's drifting doesn't announce itself. It just quietly records the wrong data until something prompts a check.
You may be in breach of your consent. If ECan audits your consent and your verification is overdue, or if your meter is found to be outside the ±5% tolerance, you may be in breach of your resource consent conditions.
Retrospective correction is difficult. If your meter has been recording inaccurately, correcting the historical record is complicated and may not be possible.
The cost of remediation is higher than the cost of staying current. Emergency meter replacement, compliance remediation, and dealing with ECan notices all cost significantly more than a routine five-yearly verification.
NZ Flow Group tracks verification due dates for our customers. If we've verified your meter before, we'll contact you when you're coming up for your next one, so you don't need to remember the date yourself.
ECan specifically recommends Blue Tick accredited providers for irrigation flow meter verification in Canterbury. NZ Flow Group holds Blue Tick accreditation through Irrigation NZ, covering installation, verification, and data hosting. Using a Blue Tick accredited provider gives you confidence that the verification is being carried out correctly with the right equipment.
No. Verification must be carried out by a qualified provider using IANZ-calibrated equipment. ECan requires the Ultrasonic Clamp-On method using a calibrated instrument, this isn't something that can be done with standard on-farm equipment.
A failed verification means your meter is operating outside the ±5% tolerance. NZ Flow Group will diagnose the cause, repair or replace affected components where possible, and re-verify. If the meter is beyond repair, we'll replace it and complete the verification so you're back in compliance quickly.
Contact NZ Flow Group. We can carry out a verification to establish your current meter accuracy and reset your compliance clock from that date. It's far better to get a verification done and documented than to continue operating with uncertainty.
NZ Flow Group are Canterbury's Blue Tick accredited verification specialists. Contact us to book or check when you're next due.