Animal hoarders in particular are putting extra strain on an already overloaded system.
SPCA Auckland's chief inspector Kevin Plowright told the Herald his team once rescued 180 cats from a single house.
"It doesn't take long to start adding up to some serious numbers, unfortunately it's increasing not reducing."
So, to alleviate some of the pressure on the Mangere centre and to ensure the SPCA Auckland keeps providing the services the communities it serves needs, the charity has announced that it will build a second centre at Hobsonville in Auckland's north west.
The two-storey satellite centre will house a 258 sqm inspectorate office where animal welfare inspectors that look after the West Auckland and North Shore areas can do paper work or conduct interviews and a 674 sq m adoption centre that Midgen hopes will encourage more residents from Auckland's western and northern suburbs to adopt from the SPCA by making it more accessible.
Plowright said the new facility will mean his team of inspectors can save "hundreds and hundreds" - if not thousands - more animals each year.
"It just all comes down to that efficiency and use of time without having to traipse through that Auckland traffic, which is horrendous at times.
"You'll just cut down enormous travel, you'll be able to do more inspections in a greater amount of time and the end result is you're saving lives. The more efficiently we can do our job, the more lives we save."
The new centre will cost $6 million to build and SPCA Auckland has set aside $4.5 million for the project.
It plans to raise another $1.5 million through fundraising over the next year.
Anyone who wants to donate can do so by visiting SPCA Auckland's website or phone the Mangere centre.
SPCA Auckland fast facts
In 2016 the organisation:
• Received 6990 animal welfare complaints, an increase of 576 on 2015
• Cared for 9359 animals in its hospital
• Performed 4241 desexing operations
• Arranged foster homes for 2415 animals