"It is going to be delivered," he said to loud applause from about 150 supporters at the campaign launch in Cornwall Park.
Mr Brown said his second big challenge would be building more affordable housing. He also promised to keep average rates increases around the rate of inflation.
His other main priority was getting the Auckland economy growing and creating jobs.
Mr Brown - a member of the Labour Party - made no mention in his speech of his support for the SkyCity convention-centre-for-pokies deal, for which he has been criticised.
He has also upset traditional supporters by refusing to back port workers in the long-running dispute on the wharves and not doing enough to resolve the issue.
Following his campaign speech, Mr Brown said he had always supported both the economic benefits the convention centre would bring to the city, and harm minimisation measures to identify problem gamblers. The ports strike, he said, was an issue between the ports company and the Maritime Union, not the council, which owns 100 per cent of the company.
Mr Brown's position on social justice issues has prompted the head of the Auckland Council's Pacific Peoples Advisory Panel, the Rev Uesifili UNasa, to stand against the mayor.
He also faces challenges from left-wing activists John Minto - a Mana Party member - and Penny Bright.
The only centre-right challenger at this stage is businessman John Palino.
Nominations for October's local body elections open on Friday and close on August 16.