Otago regional councillors have questioned if there are the tools available to make proposed changes to water-quality rules in Otago a success.
The council is working with Landcare Research to develop new tools, including the lysimeters the council is trialling on properties at Hawea and Omakau. The meters gather information on water percolation and leaching losses from soil.
Cr Trevor Kempton told the natural resources committee meeting this week there was quite a lot riding on what the council could learn from the lysimeters.
Environmental information and science director John Threlfall said the lysimeters were providing a lot of information but they were never going to be "the tool", more a "stepping stone".
"It is very early days yet."
Landcare had mentioned some "new thinking" concerning a 20m-plus lysimeter which they believed would be cheaper to install and provide readings from across a paddock rather than just in one spot, he said. However, it could take two to three years to develop.
Cr Doug Brown said there was concern about the measuring side of the proposed plan change 6A for water quality.
"It is gratifying to see the work being done," he said.
Cr Bryan Scott said the community needed to be aware of what was going on so in two years' time there was confidence the tools would work.
Cr Gretchen Robertson said the council was not 100% sure it had the right tool to go on to every farm to measure non-point discharges but it was obligated under the National Policy Statement to monitor the state of waterways by 2014.
"It is a new and tricky road ahead."
