Kaipara District Council is considering drafting a local bill to try and amend part of the Auckland super-city legislation.
The council wants the northern boundary of the Rodney district included in the Kaipara district.
Mayor Neil Tiller and chief executive Jack McKerchar say if Kaipara's boundary was shifted south, Auckland could delegate control of the southern part of Kaipara Harbour to the council.
The council would then set up an independent agency to manage the harbour.
It expects to make a decision in about a month, whether it will proceed with a local bill.
Amalgamation with Whangarei unacceptable
The Kaipara District Council has ruled out any prospect of a merger with Whangarei.
The Kaipara, Far North and Whangarei District Councils have paid $90,000 for a consultant's report about options for local government reform.
The report recommends either a single unitary authority for the whole region or two such authorities, one in the Far North and one for Whangarei and Kaipara.
But the Kaipara mayor Neil Tiller says joining Whangarei would do nothing for Kaipara ratepayers.
He says the Kaipara District Council's preference is to incorporate part of Rodney into Kaipara, and it's certainly not interested in being amalgamated into the Whangarei council.
The new Auckland Council comes into being on 1 November.