A portfolio of carbon credits held by Southland District Council to offset rate increases could be in line for a shake-up.

On Wednesday, council staff presented a report on the current market for units it holds under the Emissions Trading Scheme, recommending that they be held.

But councillors expressed a desire to get more bang for their buck, despite the units currently appreciating by around 7 percent per annum on the futures market.

Independent chair Bruce Robertson asked staff to “do the thinking” about how the credits could be put to better use.

“We need to have something that gives you (staff) the direction that you’re looking for that drives these credits a bit harder,” Robertson said after gauging the mood of the room.

According to the council report, the portfolio had traditionally held a single purpose which was to create returns through harvesting operations that would support moving rates.

Council manager finance and assurance Anne Robson told Local Democracy Reporting that while the units didn't in themselves keep rates down, council was considering selling some and investing the money into something that gave a return.

There were two kinds of emission units at play with different liabilities at harvest for both.

The first type of unit was awarded for land defined as pre-1990 which had a forestry crop in place prior to that year.

A total 82,914 units were owned by the council for that variety, with a current value of about $6 million.

The second type was for post-1989 forests, of which the council owned 26,759 units.

If the council were to harvest the latter, it would have to pay back the majority of its units.

Councillor Julie Keast said there was “no way in the world” the post-1989 credits should be touched while expressing a desire to see more output from the older variety.

“The pre-1990 ones really need to work a bit harder for our ratepayers than what they are at the moment.

“That’s just sitting there as a fluctuation of the market. They don’t actually provide a return as such to our ratepayers.”

Similar sentiments were shared by councillor Derek Chamberlain who said there was no risk to selling pre-1990 credits.

“It’s been a good investment holding onto them, but who knows where it’s going to go from now?”

Council commercial infrastructure manager Stuart O’Neill said the portfolio offset rates “quite well” and had been a wise decision that benefited future generations.

The report highlighted a recent government proposal to change how the Emissions Trading Scheme worked as an issue, saying the National Party had released policies which were likely to reduce afforestation in Southland.

Ultimately, councillors passed a resolution to periodically review its ongoing position with emissions units, while acknowledging the need to consider its investment policy.

A follow-up report is expected to follow in June.

LDR is local body journalism co-funded by RNZ and NZ On Air

Reporter: Matthew Rosenberg