Fans will also be encouraged to go to Wynyard Quarter, which council officials want to license so people can obtain food and drinks.
The Auckland Council came under heavy criticism after the RWC opening night when officials underestimated the huge crowds which turned up.
Rachael Dacy, spokeswoman for the 2011 Auckland Management Committee, said the committee wanted to ensure everyone had a great time on Sunday.
"People will obviously want to come to the waterfront and CBD so it is prudent to increase capacity where we can and provide contingencies."
If the proposal to turn Aotea Square into a fan zone is approved, rugby supporters will have to share the area with Occupy Wall St protestors.
More than 100 protesters are camped in the square, and under an agreement with city officials, they will "shuffle back" but remain there during the cup celebrations.
They have also won the backing of Mayor Len Brown, who yesterday also said they could stay in the square.
Said protester Andy Hendrie: "We warmly welcome the fans here. We are rugby fans too."
FINAL PLANS
* New fan zone at Aotea Square with big screens
* Captain Cook Wharf's capacity to increase from 10,000 to 14,000
* Fan zone space for about 4500 people to be created on Marsden Wharf
* Wynyard Quarter fan zone to be licensed to provide full food and beverage service