Staff are only at the sites at certain times, getting greywacke rock from the river or its edge, crushing it and leaving it in stockpiles.
He said there were now many more restrictions on taking gravel. The regional council restricted the volumes available.
There were also restrictions on working hours.
"You are not allowed at certain times of year because of fish, or at weekends because of anglers."
The restrictions would drive up costs for taxpayers and ratepayers, he said.
"The country hasn't actually worked that out yet. The resource consent process is quite onerous."
No submissions have been received so far, and Rangitikei District Council senior policy analyst Katrina Gray doesn't know how many to expect.
Civil engineering business Stringfellows bought the Byford quarries and construction businesses three years ago. They now have 25 central North Island quarry consents and 25 staff.
The metal made is sold to the New Zealand Transport Agency and district councils.