Local councils are being challenged to back up rising debt with infrastructure revenue

The Infrastructure Commission's found councils previously used debt to pay for new infrastructure, by creating new revenue sources.

It found debt to revenue ratios used to rise at similar rates, but no longer.

Economics director Peter Nunns says the critical question is whether councils can service debt.

He says if they don't have revenue streams to repay loans today, they'll have to cut investment budgets in the future.