"We do not have the capacity given the current numbers that are coming through and the forecast numbers," council's assets and facilities management team leader Rosemary Fletcher said.
Council staff considered five locations for the new facility but recommended the Airport Rd site.
A report said bringing the existing pound up to code would require a full rebuild and was not feasible at the current site.
The current design for the new pound has room for 48-60 kennels, up from 36, and features compliant drainage and a higher level of service to the public.
"The animal welfare issue is coming at us like an angry pit bull," mayor Hamish McDouall said as he urged councillors to approve the proposed new pound.
"We've got compliance issues and we must meet those."
Councillor Kate Joblin agreed.
"Nobody likes spending ratepayers' money but we've got to have a fit-for-purpose pound," she said.
Councillor David Bennett wanted council to explore outsourcing the pound while Alan Taylor suggested investigating a shared facility with neighbouring Rangitikei district.
But committee chairwoman Helen Craig said animal control was a tough business which should not be in the hands of private operators.
"Dog pounds are not a cleaning contract for public toilets or looking after little pussycats," she said.
"We have looked at this thing upside down and around the back and it's time we made a decision."
Chief executive Kym Fell did not believe a private operator could run it at less cost.
"This is a core role of council. It's not an art gallery."
