After a two-year transition period, about 1000 Otago consent holders still need to install meters and it will be a struggle for them comply with the deadline, the Otago Regional Council says.
New resource management regulations came into force in 2010 requiring daily recording of water use at the point of abstraction under a permit, the first - takes of more than 20 litres per second - comes into force in November.
The Government standard requires meters for consented takes, most of which are for irrigation, to assist water management on a regional and national level.
It was estimated Otago had 1600 water takes that fitted into the first category, and so far only 600 had installed water meters.
Council Regional Services director Jeff Donaldson said those who had not yet put in a meter had open water races, which were more expensive and more difficult to install than piped takes.
"I think it's going to be a struggle."
An open-channel water metering system could cost about $7000 to $10,000, with piped water meters about half that. Some landowners with multiple takes could need more than one meter.
While many water metering companies had moved into Otago anticipating the work needed to meet the new law, many had left the region because of a lack of work, Mr Donaldson said.
"We're now down to a few companies . . . and they'll certainly struggle to get around most of these properties."
Jared Halstead, manager of WaterForce, one of the companies still working in Otago, said there was "no way" all the takes would be metered in time as there were not enough resources or expertise left to deal with the "panic" of those who had left it until the last minute. Open-channel metering required experienced hydrologists and there was a limited supply of those professionals, who were also needed in other regions such as Canterbury, which was facing similar problems.
"I think they've been hoping the regional council will change its mind, but this is driven by central Government, so the regional council's hands are tied."
Mr Donaldson said there were dispensations available for takes where it was impracticable to measure at the point of take, but under consent conditions those with water takes were required to provide the council with good quality data, and not doing so meant they could face the council's enforcement processes, including infringement notices and prosecution.
Given the difficulties that could be faced by those who had left it until the last minute, the council would look at who had made efforts to get one installed before taking the issue further, he said.
"They need to get in touch with a service provider."
The council had been proactive, doing mail drops and expos on the topic to inform those with takes of their responsibilities.
Council chief executive Graeme Martin said at a recent committee meeting there was some reluctance in Central Otago because of the issue in the region around the district council metering and selling water.
"There is a fear of water meters. But that has nothing to do with us."
Ministry of Environment director of environmental regulation Kevin Currie said the Resource Management Act had provisions for compliance, including abatement notices and enforcement orders.
"The ministry expects councils to ensure that people measure their water take, as required by the regulations."
Councils had options in terms of what type and level of enforcement action they pursue and different penalties would apply depending on the type of enforcement action taken, he said.
Federated Farmers Otago deputy president Mike Lord said farmers, like anyone, were not exempt from the law and they would be wise to get on and get the technology installed.